#archived-shaders | Official Unity Discord | Page 115

fervent tinsel Mar 29, 2019, 9:10 PM

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HDRP renders things camera relative

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HDRP uses camera relative rendering. This means that there is a good rendering precision even far away from the origin of the world. This has an impact on all the shaders used with HDRP.

broken field Mar 29, 2019, 9:26 PM

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it is both camera relative and reverse depth

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holds up for pretty much any draw distance thrown at it

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builtin just cannot render my game in that respect sadly

devout quarry Mar 29, 2019, 10:02 PM

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I'm creating/testing so many graphs to get the best depth values

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📎 unknown.png

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I'm gonna dream in nodes tonight

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bottom left is most promising atm

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is view space the same as eye space?

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and if so, why is the naming not consistent in shader graph

frigid zinc Mar 29, 2019, 10:30 PM

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where are those terms used?

devout quarry Mar 29, 2019, 10:34 PM

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the 'position' node has a 'view' space as well as 'object', 'world', and 'tangent'

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and the scene depth node has an 'eye' sampling mode

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so I was thinking that eye and view were related

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and in the documentation of the scene depth node they refer to 'eye space units' as well

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so that implies that there is an 'eye space' and a 'view space'

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and eye/view sound related to me

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so I'm confused in how they are different

frigid zinc Mar 29, 2019, 10:42 PM

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https://docs.unity3d.com/Packages/com.unity.shadergraph@5.10/manual/Scene-Depth-Node.html

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documentation doesn't really explain what an 'eye space unit' is

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so i have no idea

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but it's a distance, not an angle

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or position

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so not the same as you would get from position node

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https://gamedev.stackexchange.com/questions/65783/what-are-world-space-and-eye-space-in-game-development

Game Development Stack Exchange

What are "world space" and "eye space" in game development?

I am reading a book about 3D concepts and OpenGL. The book always talks about world space, eye space, and so on.
What exactly is a world inside the computer monitor screen?
What is the world space?

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defined here but i'm not sure i get the definition lol

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sounds like eye space is close to the same thing as camera space

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if not the same thing

devout quarry Mar 29, 2019, 10:47 PM

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because we use the camera as our eye?

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if it's relative to eye coordinates

frigid zinc Mar 29, 2019, 10:48 PM

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https://stackoverflow.com/questions/15588860/what-exactly-are-eye-space-coordinates

Stack Overflow

What exactly are eye space coordinates?

As I am learning OpenGL I often stumble upon so-called eye space coordinates.

If I am right, you typically have three matrices. Model matrix, view matrix and projection matrix. Though I am not ent...

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another attempt at defining

devout quarry Mar 29, 2019, 10:49 PM

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thank you, gonna read these tomorrow morning

frigid zinc Mar 29, 2019, 10:49 PM

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looks like Eye space is also the same as UNITY_MV

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Model View matrix

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if this second one is right

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so it's not exactly same as view, it's a combination of object and view

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yeah this kind of confirms it: http://www.songho.ca/opengl/gl_transform.html

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It is yielded by multiplying GL_MODELVIEW matrix and object coordinates.```

stark hornet Mar 30, 2019, 1:21 AM

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Is it possible with shaders to count how many pixels of a mesh are being drawn?
So for example if I have a quad and use a discard function to not draw pixels within a circle radius, is it possible to check what % of pixels of the quad I discarded?

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And get that percentage value to an external script as a variable?

frigid zinc Mar 30, 2019, 1:49 AM

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i honestly can't say i would know how to do that

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if a shader can modify external variables i'd say you could

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but I have a feeling you can't

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or if you could it would probably slow things down considerably

stark hornet Mar 30, 2019, 2:12 AM

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Seems the closest thing to what I asked would be to generate a pixel color histogram with compute shaders which feels like it would take quite some processing power... And since I want that for every object and probably a couple of times per second.... Seems like it's a nope

still carbon Mar 30, 2019, 4:24 AM

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There might be a better approach in general to your goal. What is it you're trying to achieve game mechanic wise?

brazen comet Mar 30, 2019, 8:23 AM

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Hi shader people ! Quick question : I have a two-pass shader made in amplify that works well but is obviously not compatible with HDRP. So i'm heading toward creating again in Shader Graph , but is it able to do multi pass ? Everything will be compatible with HDRP and LWRP then ?

main blade Mar 30, 2019, 9:56 AM

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anyone have any experience with ray tracing?

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I am trying to get a mesh's uv with the Moller Intersection

devout quarry Mar 30, 2019, 12:39 PM

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I'm going to create a water shader tutorial

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📎 unknown.png

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I mostly make this break-down for myself but I think it could be useful for others too

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I'm at depth based water colors and opacity, and foam lines

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I'm still going to add animated foam textures and water displacement, after that I'll share it

stark hornet Mar 30, 2019, 2:13 PM

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@still carbon I made a shader that "reveals" whatever surface it touches. Now I need to check what % of the surface it has revealed to do other stuff based on that

📎 Texture_Revealer_Stencil.gif

supple root Mar 30, 2019, 2:26 PM

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@stark hornet does that only work for spheres?

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I mean as the brush

stark hornet Mar 30, 2019, 2:26 PM

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@supple root no, it works with any non-concave mesh

supple root Mar 30, 2019, 2:26 PM

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ohkk

stark hornet Mar 30, 2019, 2:27 PM

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I still need to fix it in order to work with concave meshes

sand perch Mar 30, 2019, 3:19 PM

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@stark hornet the histogram you're talking about might be doable, that's how they do part of the auto-exposure in AAA games

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they produce a histogram of the whole screen as a postprocess,

stark hornet Mar 30, 2019, 3:23 PM

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@sand perch yeah it definitely seems like a good tool to use with the output of the whole screen

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but it seems it would not be ideal for what I want, which is have 1 histogram per object that takes into account also the faces of the object that face away and are occluded by other objects

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I will probably end up doing a solution that doesn't use shaders for that. Maybe something like, take into account the radius or bounding box of the object holding the shader and do calculations to check how much of the surface is covered by it

stark hornet Mar 30, 2019, 5:41 PM

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Question about draw calls, batching and geometry: When doing dynamic batching on multiple objects with the same shader, does the GPU have to process the geometry for both anyways?

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Dynamic batching: for small enough Meshes, this transforms their vertices on the CPU, groups many similar vertices together, and draws them all in one go.

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the docs say that, does that mean for example 2 vertices in the same place get treated as one? I mean in the sense that the GPU only processes one

frigid zinc Mar 30, 2019, 5:43 PM

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no

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it just combines the meshes into one draw call

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so instead of Draw Mesh A: 1 draw call
Draw mesh B: 1 draw call

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it's
Combine meshes A and B : 1 draw call

stark hornet Mar 30, 2019, 5:44 PM

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so the geometry get taken into acount anyways, right?

frigid zinc Mar 30, 2019, 5:44 PM

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it's not about eliminating anything, it's about doing it all in one go

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yes

stark hornet Mar 30, 2019, 5:44 PM

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I see...

frigid zinc Mar 30, 2019, 5:45 PM

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if they removed vertices based on some arbitrary distance it would lead to visual artifacts

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and you dont' want that

stark hornet Mar 30, 2019, 5:46 PM

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@frigid zinc yeah that makes sense

frigid zinc Mar 30, 2019, 5:46 PM

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tools like blender can do that, because they have you to fix any problems

stark hornet Mar 30, 2019, 5:46 PM

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I'm testing performance for shaders using : A) 1 sphere with 1 shader that has 3 passes and B) 3 spheres with 1 shader each with 1 pass on each shader

frigid zinc Mar 30, 2019, 5:46 PM

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but an automated pipeline has no way to know what is correct and what isn't

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so they don't do it

stark hornet Mar 30, 2019, 5:46 PM

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with B I can batch all the drawcalls but seems pretty much the same performance as A

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I guess that's because the triplicated geometry on case B

frigid zinc Mar 30, 2019, 5:48 PM

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yeah you wont' see much gain from such a small sample size

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you need to test with several hundred meshes

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then you'll see the difference

stark hornet Mar 30, 2019, 5:48 PM

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yeah I'm doing stress tests with 4000 objects

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I see a bit of performance increase with B when using simple meshes like cubes

frigid zinc Mar 30, 2019, 5:49 PM

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with perfect batching you'd see it go from 4000 drawcalls to 1

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and the difference should be pretty substantial

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but there's a LOT of things that break batching

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so you may not be getting the batching at all

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you should check the stats window and see

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you should see the "Number of drawcalls saved through batching" change when it's on or off

stark hornet Mar 30, 2019, 6:00 PM

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with One shader and 3 Passes I get this and results in average of 61 fps

📎 One_Shader_Multiple_Passes_61_fps.png

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With 2 shaders and 1 pass each I get this and results in average of 75 fps

📎 Mulitple_Shaders_1_Pass_Each_75fps.png

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Option B seems to give better results, and even less verts/tris to process? even tho the actual number of meshes in the scene with option B is the double of option A

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when using 1 shader with 3 passes on a cube I get this geometry count: 36 triangles and 72 verts

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when using 1 shader with 1 pass on a cube I get this geometry count: 12 triangles, 24 verts

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does that mean that for each pass I am creating a new "copy" of the geometry of the mesh?

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that is the tris/vert count from the Stats window

frigid zinc Mar 30, 2019, 6:10 PM

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you're processing the same data more than once

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so it counts that as 'more verts'

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technically it just means 'more operations on the same verts'

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but it's the same amount of work as if you draw the same mesh 3 times

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so either way of defining it works

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1 shader with 3 passes = everything drawn 3 times

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2 shaders with 1 pass = everything drawn 2 times

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so of course the second is going to be faster

stark hornet Mar 30, 2019, 6:12 PM

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I see, so I'm just better of with option B that lets me do Dynamic batching on all the objects even tho I have more actual gameObjects that I have to take care off (I was avoiding doing this approach because I'm not sure if it would casue issues when moving thousands of them at the same time via script)

frigid zinc Mar 30, 2019, 6:12 PM

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question is why aren't you testing with 3 shaders with 1 pass, for a real apples to apples comparison?

stark hornet Mar 30, 2019, 6:13 PM

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@frigid zinc Option B is just the result of trying to separate the 1 shader 3 passes into different shaders for the purposes of batching

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I ended up not needing one of the passes this way

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so I got to the same result with 2 shaders with 1 pass each

devout quarry Mar 30, 2019, 6:13 PM

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shader graph question

frigid zinc Mar 30, 2019, 6:14 PM

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ok then sounds like that would be the way to go

devout quarry Mar 30, 2019, 6:14 PM

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If I have a remap node that remaps to 0-1 and a clamp not after that one that clamps to 0-1

frigid zinc Mar 30, 2019, 6:14 PM

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a pass saved is performance earned

devout quarry Mar 30, 2019, 6:14 PM

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I can just remove the clamp node right

frigid zinc Mar 30, 2019, 6:14 PM

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sounds like you could @devout quarry

stark hornet Mar 30, 2019, 6:15 PM

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@frigid zinc thanks a buch for taking the time to answer my trivial and somewhat repetitive questions! 😊 I'll go back to keep on learning shaders and rendering stuff so I don't need to flood this discord channel with questions that often!

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heh 😅

devout quarry Mar 30, 2019, 6:16 PM

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it doesn't seem to have an effect either

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ty

frigid zinc Mar 30, 2019, 6:17 PM

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np 😃

broken field Mar 30, 2019, 6:18 PM

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If using SRP please do evaluate your decision differently

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because with SRP batcher, you're batching per shader not material etc, and dynamic batching can often lead to less perf if CPU bound

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(try with and without instancing etc)

frigid zinc Mar 30, 2019, 6:22 PM

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if your CPU bound you have other issues heh

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but i get what you're saying. in any event since he's hand coding his shaders, I assumed he's on Legacy.

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I would like more info on that though if you can provide it. I've read nothing to suggest Batching works differently on SRP. They only say it's faster. @broken field

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https://i.imgur.com/ZDiPw0t.png

Imgur

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or maybe you're thinking of the "SRP Batcher" which is a whole other thing:

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https://blogs.unity3d.com/2019/02/28/srp-batcher-speed-up-your-rendering/

Unity Technologies Blog

SRP Batcher: Speed up your rendering! – Unity Blog

In 2018, we’ve introduced a highly customizable rendering technology we call Scriptable Render Pipeline (SRP). A part of this is a new low-level engine ren...

stark hornet Mar 30, 2019, 6:39 PM

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@broken field @frigid zinc yeah I'm hand coding my shaders and using de default rendering pipeling. I don't know ANYTHING about SRP, LWRP or HDRP

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all I can guess is they give more control to decide what renders in which order and stuff like that?

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I was just using Unity 2017 until a couple of days ago, when I updated to 2018.3 I gave a quick read to some of the new stuff and saw the new rendering pipelines mentioned a couple times but for now I haven't read anything about them

frigid zinc Mar 30, 2019, 6:42 PM

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yeah it's a whole new pipeline written from the ground up

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better in every way you could say

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but breaks compatibility with just about everything that used Legacy

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so that's the downside

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you can't really hand code shaders, but instead you need to use Shadergraph

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which is similar to ShaderForge/Amplify for legacy

broken field Mar 30, 2019, 6:44 PM

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if you are a DIY enthusiast then SRP is for you

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the legacy (builtin) renderer is well featured but quite old > a decade of cruft

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they have been removing and cleaning it up best they could over the years but it's what it is, it is pretty good

frigid zinc Mar 30, 2019, 6:45 PM

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it's fine but there's always new techniques beinge developed

broken field Mar 30, 2019, 6:45 PM

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but for learning the guts and doing your own, builtin is a bad choice.

frigid zinc Mar 30, 2019, 6:45 PM

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and it's good Unity is rebooting using them

broken field Mar 30, 2019, 6:45 PM

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its far too distant from hw

frigid zinc Mar 30, 2019, 6:45 PM

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ehhhh i don't agree with that

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abstraction is good

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for starting out

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best place to learn

broken field Mar 30, 2019, 6:46 PM

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I would probably suggest a SRP based off LWRP because it is a lot simpler than builtin

frigid zinc Mar 30, 2019, 6:46 PM

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then you can start diving into the guts

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honestly for me LWRP is a non-starter

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it's missing too many basic things

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(but then again I don't go for no phone games)

broken field Mar 30, 2019, 6:47 PM

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it's true it's simpler but if you bake everything it can still look nice I think

frigid zinc Mar 30, 2019, 6:48 PM

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no decals, no planar reflections, no translucency what else

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i forget all the stuff it doesn't have lol

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no skin or hair shader i bet

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aniso?

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i think that's why i like legacy

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there is no limit to what you can do with it

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from the lowest low to the highest high

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funny enough, SRP seems very rigid and inflexible, which considering why it was created, is ironic

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sure i could 'write my own SRP' but i'll get on that as soon as I become a millionaire and can afford a team of devs 😛

broken field Mar 30, 2019, 6:51 PM

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SRP is very open though if you copy it you can take it wherever you please, its super simple for the LWRP version at least

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it's just a bunch of loops basically

frigid zinc Mar 30, 2019, 6:51 PM

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maybe you're right in that respect

broken field Mar 30, 2019, 6:52 PM

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you can feasibly write your own 2D renderer from scratch in an hour if you wanted :P

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you, not a beginner that is

frigid zinc Mar 30, 2019, 6:52 PM

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i only dove into LWRP enough to find Yannis' shadow setting

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but it didn't really seem that simple

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i feel it would take months to really know the code backward and forward enough to seriously modify it

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maybe weeks, I tend to overestimate how long things take 😛

broken field Mar 30, 2019, 6:54 PM

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LWRP has most of the complexity in the shader which tries to bond valve's vr forward technique with something else and I think it kind of falls short in a number of areas but I get why it exists: LWRP is really only here because HDRP's proper goal would've been in 2 years time not end of this year, and in 2 year's time most things will be running on HDRP without performance issues (like any AAA renderer basically)...but that's too long, too far etc, so they made LWRP - at least that's what I took away from looking at the dev processes at Unity.

frigid zinc Mar 30, 2019, 6:54 PM

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makes sense

broken field Mar 30, 2019, 6:54 PM

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ideally unity should've just focussed on keeping builtin nice and optimised instead of doing LWRP

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builtin for mobile + vr + anyhing and HDRP for the next gen nuts

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because ultimately LWRP will just be discarded in the end or used for a template to design new games with

I get that its faster if you use it as intended within it's limits but for fast mobile games you will end up with similar real world perf if you just throw a few simple vert shaders or unlits at builtin

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I mean I shipped a few mobile games with the old builtin which was frankly much slower than today and those were 60fps

frigid zinc Mar 30, 2019, 6:57 PM

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yeah i already see that everyone using LWRP want to push it beyond it's limits heh

broken field Mar 30, 2019, 6:57 PM

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all I needed to do was write a few classic simple frag/vert shaders and avoid surface shaders

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yeah LWRP is just an awkward stop-gap to me. I do like what it represents but it's not more useful for more people atm

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had amplify shader editor not existed, LWRP would be mandatory for a lot of people

frigid zinc Mar 30, 2019, 6:58 PM

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probably

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not everyone can write shaders the manual way

broken field Mar 30, 2019, 6:59 PM

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LWRP is faster if your games's conditions require most of LWRP

but it's turning out most people don't have those exact conditions

frigid zinc Mar 30, 2019, 6:59 PM

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i struggled a lot myself to learn to write shaders

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and i'm a semi-genius ;p

broken field Mar 30, 2019, 7:00 PM

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its funny, a lot of optimisations in HDRP are quite similar to what I did when I wrote all the vert and frag shaders from scratch for ps vita

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they reuse everything and do some foul tricks

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it's not all perfect utopia code :P

frigid zinc Mar 30, 2019, 7:00 PM

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devious minds think alike i guess 😛

broken field Mar 30, 2019, 7:00 PM

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but my "renderer" back then had no per pixel lighting

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instead we focused on having higher poly counts (no extra passes so it's safer) and vert lighting

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i had subsurface scattering working fine on this primitive device

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if you could call it that - it's per vert so I already had the light passing right through the meshes by distance to vert, so for "sss" it was just a matter of controlling how much one wanted to occlude that light on the far side of the object

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a dot and an exposed multiplier was all it took, plus multiply by vertex red or such to control where

frigid zinc Mar 30, 2019, 7:02 PM

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yeah that's the basic way to do it

broken field Mar 30, 2019, 7:03 PM

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primitive ways but so so fast

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and really quite nice looking on a small screen you know?

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There's not much reason for overkill on mobile, vert lit is actually sufficient given good shadows and some fairly nice lightweight post fx

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unless you are 12 with an earring and hipster hair with a $2000 mobile phone that has a screen the size of a4 paper

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heh i'm arguing against lwrp while arguinf for lwrp

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shrugs

frigid zinc Mar 30, 2019, 7:07 PM

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hehe

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for phones it's fine as you say

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i'm just not interested in making phone games

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99% are free

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and i seriously doubt many pay for the paid ones

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and i find ads morally reprehensible 😛

broken field Mar 30, 2019, 7:24 PM

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ads tick me off

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and apparently tick apple off too

stark hornet Mar 30, 2019, 7:25 PM

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for what you say seems like the new Scriptable Render Pipeline could be good to increase rendering performance

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as of now, how hard would it be for a beginner like me to adapt a bunch of hand written shaders to use the new rendering pipelines ?

broken field Mar 30, 2019, 7:25 PM

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its fastest because it does absolutely nothing at all where builtin does a lot of stuff if you like it or not

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but it does only qualify if you make your own shaders of course

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(for your case I mean)

stark hornet Mar 30, 2019, 7:27 PM

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but it would require to substantially change a bunch of stuff in the de code in my shaders, right?

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it's not just a matter of plug and you are all set

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at least that's the impression I'm getting from reading what you both said about the SRP

frigid zinc Mar 30, 2019, 7:28 PM

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yes legacy shaders won't work

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you'd have to make replacements using Shadergraph.

stark hornet Mar 30, 2019, 7:30 PM

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hmmm... I see, for now it seems I'm better off with the legacy pipeline and shaders because I'm still learning how to properly and "efficiently" write my own shaders

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and most of the beginner-friendly resources online seem to use the legacy stuff

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and to be honest I don't know how much time it would take me to properly learn SRP in order to make good use of it

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I didn't even know how a shader worked 6 months ago 😅

broken field Mar 30, 2019, 7:46 PM

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yeah people don't realise that it's not something that just happens but rendering a triangle in a specific way with a little program

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pixel by pixel

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:D

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being on this side of the fence, i'm grateful I don't look for "how was that done" any more when I play games

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I stopped doing that around the end of 16 bit

stark hornet Mar 31, 2019, 2:23 PM

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Question about Stencil Buffer and ZTest:

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Does ZTest Greater affect the order in which objects write to the Stencil Buffer?

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Or the writing to the Stencil Buffer happens in the order of the Render Queue regardless of whatever the ZTest is?

frigid zinc Mar 31, 2019, 4:47 PM

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Unity's documentation says this:
How should depth testing be performed. Default is LEqual (draw objects in from or at the distance as existing objects; hide objects behind them).

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it uses the term 'existing objects' which would lead me to believe it's just modifying how the things already rendered are interpreted by this shader's operations. So that wouldn't change the render queue at all, just changes what portions of the current object are drawn.

stark hornet Mar 31, 2019, 5:26 PM

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Yeah makes sense

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I guess the Stencil Values get writen as long as their pixels are visibles

frigid zinc Mar 31, 2019, 5:27 PM

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yes depending on the results of the test mode you specify

stark hornet Mar 31, 2019, 6:51 PM

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Is there a way to pass data between 2 shaders? For example passing the world position of a pixel from one shader to another?

frigid zinc Mar 31, 2019, 7:38 PM

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basically the only thing i could find on this is this:

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Regardless of each APIs terminology, you need to write to an intermediate buffer and pass that buffer to the next shader program. A widely used technique is to render to a texture and pass the texture into the next shader. Most of the advanced effects are implemented using a variation of this technique most; notably all of the deferred renders use this to generate of what is called a G-Buffer that contains several info about the geometry in the scene (Position, Normals, Tangents) all those are output of the geometry pass of the deffered render and encoded in buffer.

stark hornet Mar 31, 2019, 8:15 PM

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@frigid zinc thanks! I'll do some research on G-Buffers

frigid zinc Mar 31, 2019, 8:17 PM

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well that's just an example

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G-Buffer is something maintained by the deferred rendering path

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it's not really something you can use for your own purposes.

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https://forum.unity.com/threads/accessing-deferred-renderer-g-buffers.315223/

Unity Forum

Accessing Deferred Renderer G-Buffers

Hi,

I'd like to save the PBS deferred G-Buffers to disk, I want to use the resulting textures in PBS materials. Is this possible without writing a...

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as explained here you can access the g-Buffer and save it's data to a texture, but if you tried to write to it, you'd be altering the whole overall scene, not just whatever your shader is working on

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think of it as an intermediary screen buffer.

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basically the only real choice is to write your data to a texture and pass that to the next shader.

stark hornet Mar 31, 2019, 8:22 PM

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@frigid zinc so what I could use is something like Render Textures?

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I was under the impression those were only to capture the whole screen

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I would need something to capture the pixels of 1 texture and transfer them to another

frigid zinc Mar 31, 2019, 8:24 PM

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as I understand it, it wouldn't be any different than the texture you input

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a model h as UV space and the surface is mapped in that space

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so your diffuse is a single texture for any surface

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if you write your output buffer indexed by UV in the same way, your data will be a single texture mapped in UV space, in similar fashion

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so whatever you're doing, you would have a pixel per pixel to use in the next shader

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i hope that makes sense

stark hornet Mar 31, 2019, 8:26 PM

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yeah it makes sense,

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but I am not entirely sure how I could do that with my current situation

frigid zinc Mar 31, 2019, 8:27 PM

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yeah honestly I've never had need to do that, so i have no idea on how to accomplish it

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but it sounds like you'd probably want a RenderTexture as an input so you can write your data to it

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and then that same texture as an input to the other so it can read the data from it

stark hornet Mar 31, 2019, 8:28 PM

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I have this as the result of a couple of stencil masks and what I need now is to take that result and put it into a different shader so I can play better with the Depth Buffer

📎 1f4c943ed2dce3c7de35744e6e8ca93d.png

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So I'm exploring different ways of achieving that

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an idea I had was maybe create a new texture at runtime using Texture2D.GetPixels and Texture2D.SetPixels

frigid zinc Mar 31, 2019, 8:32 PM

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problem is how would you pass data to such a script so it can setPixels

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the writing has to occur within the shader afaik

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there's no way you can avoid doing this? reading and writing is going to have overhead as well

atomic echo Mar 31, 2019, 8:33 PM

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Ooof shader graph is fighting me on this one.

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Trying to make a simple panning texture in the distortion distance.

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Worked for a bit, now it just outputs solid color.

stark hornet Mar 31, 2019, 8:34 PM

#

I need to play around with my approach to stencils so maybe I can avoid the problem I'm having, which is for that result in the screenshot I posted: I have to provide an initial geometry(cube) with ZWrite On to obtain that result, but that also occludes other objects using the same stencil masks...

frigid zinc Mar 31, 2019, 8:35 PM

#

https://docs.unity3d.com/Manual/class-CustomRenderTexture.html

#

this page talks about rendertextures and how to write to them from a shader

#

and second example is for reading i think

#

no second is for 'initializing' the rendertexture

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i guess reading is the same as any regular texture

stark hornet Mar 31, 2019, 8:39 PM

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@frigid zinc thanks for the link! I'll give it a go

stark hornet Mar 31, 2019, 10:52 PM

#

what is the uniform keyword used for in shaders?

#

I'm making a shader that has an array of float4 for scrolling through colors but using the uniform keyword or not doesn't make any difference

#

uniform float4 _Colors [5];```

#

I set the arrays from an external script

#

myMaterial.SetVectorArray("_Colors", colors);```

#

the Nvidia CG website says this:

#

The uniform qualifier indicates the source of a variable's initial value. When a Cg program declares a variable as uniform , it conveys that the variable's initial value comes from an environment that is external to the specified Cg program

#

So from that I assume the "uniform" keyword serves to mark a variable in a shader that comes from outside the shader? But it doesn't seem to matter in my shader, works either way

still carbon Mar 31, 2019, 11:29 PM

#

I recall hearing that all variables are uniform by default for unity CG compilation

stark hornet Mar 31, 2019, 11:30 PM

#

@still carbon oh! That could explain why it doesn't make any difference

#

for now I'll keep using the uniform keyword as a reminder that those variables come from outside the shader

#

but I wonder, is there any situation where using that "uniform" keyword really matters? or any situation where not using that keyword will break a shader?

frigid zinc Mar 31, 2019, 11:37 PM

#

yeah I have seen all the various stuff and never really saw the point of it half/float/uniform it doesn't seem to matter

#

i know 'half' is half precision but I've never really seen it explained why you would want that

stark hornet Mar 31, 2019, 11:42 PM

#

besides what Invertex said about them being automatically set to uniform by Unity, the only explanation for using it I could find online is this:

#

because it's safer in the long term and more maintainable. Maybe down the line Unity might change up their compiling so that they are not uniform by default, then a bunch of your shaders might need updating

still carbon Mar 31, 2019, 11:43 PM

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Which was a forum comment by me too LUL

stark hornet Mar 31, 2019, 11:43 PM

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lol, nice

broken field Apr 1, 2019, 2:06 AM

#

variables like fixed and half are still compiled to fixed and half depending on target platform (usually mobile, if the particular mobile supports it)

#

but fixed is mabye just float on desktop gpus

frigid zinc Apr 1, 2019, 2:14 AM

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yeah i should probably read up on that stuff to understand it better

uncut karma Apr 1, 2019, 3:22 AM

#

@stark hornet i recommend using LWRP..lol. or at least looking into it in a test project and experimenting with stencils. With legacy depending on what you need you may end up with a weird workaround or less efficient solution, the nice thing with LWRP is it can be modified without much trouble once wrapping your head around how it is intended to function, and overall it gives a bit more insight into how a frame gets rendered if you're interested in the renderin/shader side of things

#

it does make sense though that most of the resources online are based around legacy stuff so it could be better for figuring things out

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personally i think all the shader code in LWRP is better formatted and easier to read, and the core shader library of helper functionality/macros is way better organized than the old unity built in shader stuff

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maybe also read this tutorial for a very high level idea of render pipelines too if you do look into LWRP a bit, https://catlikecoding.com/unity/tutorials/scriptable-render-pipeline/custom-pipeline/

Custom Pipeline

A Unity Scriptable Render Pipeline tutorial about creating a custom pipeline.

#

(i dont recommend actually using that tutorial for the basis of your own render pipeline though, its more just to understand the core functionality Unity provides and reference it against LWRP)

stark hornet Apr 1, 2019, 4:10 AM

#

@uncut karma yeah that's pretty much the issue I'm experience right now with Stencils and the default pipeline, there's some cases where I am like "oh I would like to use the Depth Buffer in this specific and arbitrary way" or "oh man I wish I could have more control over how Stencils and Depth writing and reading work with each other here" so I end up with solutions that are too rigid and cumbersome to make them work efficiently

#

I'll look into LWRP more as a learning tool than anything else because I doubt I will be able to achieve by myself a good enough Render Pipeline that works better than the legacy

#

But definitely might be worth the time to do a couple tests just for the sake of getting a solid grasp on rendering related topics

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My priority for now is focused on improving my knowledge of shader coding with the default pipeline, and I definitely need to get on learning lightning related stuff because my knowledge of that is pretty much nonexistent apart from some basic concepts that I picked up here and there while learning shader coding 😅

#

Thanks for the link! I'll take a look at it

prime gazelle Apr 1, 2019, 4:36 PM

#

i'm using two plane with mobile/cutout shader but when i'm facing one of them transparent plane for the other grass is visible how do i get rid of it

📎 unknown.png

broken field Apr 1, 2019, 5:07 PM

#

I'm surprised that a mobile "cutout" variant even exists.

#

given that cutout will be slow on tiled gpus

frigid zinc Apr 1, 2019, 5:12 PM

#

speaking of Moble and GPUs

#

https://docs.unity3d.com/Manual/SL-DataTypesAndPrecision.html

#

I did get around to researching about the usage of half/fixed/uniform, and all the other variable types

#

and it all boils down to performance on mobile

#

The half and fixed types only become relevant when targeting mobile GPUs, where these types primarily exist for power (and sometimes performance) constraints. Keep in mind that you need to test your shaders on mobile to see whether or not you are running into precision/numerical issues.```

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so for PC it doesn't matter what you use, it will all end up as regular float anyway

#

but it does matter for mobile, using the proper types can improve performance and energy efficiency.

devout quarry Apr 1, 2019, 5:32 PM

#

SG suestion

#

📎 unknown.png

#

So I generate noise (top left node) and I want to add the white spots on top of a blue color

#

but as you can see it also adds the black part of the noise

#

how do I make it so that only the white spot's get added onto the blue color?

frigid zinc Apr 1, 2019, 5:34 PM

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I don't see how it could be adding black, since that's zero

#

zero + number will always = number

#

not black (zero)

devout quarry Apr 1, 2019, 5:35 PM

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well this is without me adding it

#

📎 unknown.png

frigid zinc Apr 1, 2019, 5:36 PM

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unless there's some bug with the add node

devout quarry Apr 1, 2019, 5:36 PM

#

and this is when I add something similar

#

📎 unknown.png

#

but in the form of a texture instead of noise

frigid zinc Apr 1, 2019, 5:36 PM

#

yeah that looks more like what I would expect

somber bolt Apr 1, 2019, 5:36 PM

#

Anyone successfully using PostProcessing v2 on Mobile? If so, could you share notes?
All I get is a black screen, I think the same as this bug report
https://issuetracker.unity3d.com/issues/ios-post-processing-stack-v2-on-ios-with-a10-or-lower-chip-gives-just-a-dark-screen

Unity IssueTracker - [iOS] Post Processing Stack V2 on iOS with A1...

To reproduce: 1. Open users attached project "PostProcessingStack.zip" 2. Build for iOS 3. Deploy the Xcode project to an iOS device...

frigid zinc Apr 1, 2019, 5:37 PM

#

remap is only outputting a Vector1

#

but it's being cast to a vector4

#

maybe a problem with that

#

try using a node to ensure Alpha (the 4th number) is always 1.0

#

that could be the issuse

#

i'm sure they have a vector building node

stone sandal Apr 1, 2019, 5:39 PM

#

also worth double checking that your generated noise doesn't have any negative numbers in it, that could be creating weird behavior in the add node as well

devout quarry Apr 1, 2019, 5:40 PM

#

I'm remapping to a 0-1 output

#

I'll try checking if the vector1-vector4 is the issue

#

probably is

stark hornet Apr 1, 2019, 5:53 PM

#

what is more performant in a shader? these are 2 simple examples but I intend to do this with at least 1000 items

#

         {
             output._WorldPositions[i] = mul(_MyMatrixArray[i], worldPos);
         }```

#

or:

#

output._WorldPositions[1] = mul(_MyMatrixArray[1], worldPos);```

devout quarry Apr 1, 2019, 5:54 PM

#

idk man this add node seems broken

frigid zinc Apr 1, 2019, 5:54 PM

#

what did you try to fix it?

#

@stark hornet I'd say the difference is probably minmal. but it's not unusual for people to 'unroll' loops for better performance. of course the code is larger in that instance.

devout quarry Apr 1, 2019, 5:56 PM

#

I tried building a new vector, and

📎 unknown.png

#

so my texture gives me these outputs right

#

alpha is 1

#

so I tried building a vector4 with my noise

#

📎 unknown.png

#

a vector4 with an alpha that's 1

#

and it's giving me the expected r,g,b,a values

#

but tbh I think something else is the issue, because the blue color that I wanted to add the texture onto also change's color when I add the texture

#

so I don't think my noise output is the issue but something else, gonna investigate a bit

frigid zinc Apr 1, 2019, 5:59 PM

#

i'd make sure your remap is remapping to 0-1

devout quarry Apr 1, 2019, 5:59 PM

#

yep it is

frigid zinc Apr 1, 2019, 5:59 PM

#

because the only other thing I can think of is that it's not

#

or that there's something wrong with add (but that seems unlikely since it works with the other input)

devout quarry Apr 1, 2019, 5:59 PM

#

lol okay so

#

I added a clamp01 after the remap

#

and it works

frigid zinc Apr 1, 2019, 6:00 PM

#

hmm

devout quarry Apr 1, 2019, 6:00 PM

#

📎 unknown.png

#

my remap is set to a 0-1 output

frigid zinc Apr 1, 2019, 6:00 PM

#

so maybe remap has a problem

devout quarry Apr 1, 2019, 6:00 PM

#

I thought that was the whole point of remap

#

📎 unknown.png

#

but yeah getting good result now

stark hornet Apr 1, 2019, 6:01 PM

#

@frigid zinc so le'ts say I do a for loop in a vertex shader with a couple thousand items... would I see a noticeable performance hit?

#

what alternatives exist to not use for loops in shaders?

frigid zinc Apr 1, 2019, 6:01 PM

#

I don't really know the statistics on that

stark hornet Apr 1, 2019, 6:01 PM

#

i've read somewhere that sometimes people use "step" to avoid loops in shaders

#

but I may be remembering incorrectly

#

maybe that was for conditionals

frigid zinc Apr 1, 2019, 6:02 PM

#

https://computergraphics.stackexchange.com/questions/2153/loop-performance-in-a-shader

Computer Graphics Stack Exchange

Loop performance in a shader

I am wondering what's the best way to integrate a dynamic loop function in a shader?

First, it seems that dynamic arrays are not possible. So, is it better to create a maximum size array and only ...

#

from that answer it seems the compiler may do unrolling for you anyway

#

unrolling is really the only way to not use a for loop that I know of

#

also I think this is sound advice from a page I found

#

unlike on cpu where unrolling small loops should increase execution time on older gpu its better to use loops for more compact code instead of unrolling them, thus saving more instruction for later calculations. but current shader models support many of gpu instruction so loops are not good or bad, but either how and in what context they are used.

#

i'd probably not fret over it a lot

stark hornet Apr 1, 2019, 6:04 PM

#

hmmm, I see

frigid zinc Apr 1, 2019, 6:04 PM

#

the compiler will do what is best for the case

stark hornet Apr 1, 2019, 6:05 PM

#

@frigid zinc thanks for the info! I'll do some stress tests with 10k items in multiple contexts and see what happens

frigid zinc Apr 1, 2019, 6:05 PM

#

ok, have fun 😉

stark hornet Apr 1, 2019, 6:05 PM

#

hope my GPU doesn't explode or something! 🙃

wraith tide Apr 1, 2019, 6:46 PM

#

Hey guys, quick question. Is there a way to force unity to render a certain shader using an unlimited amount of per-pixel lights?

#

Surface shader

stark hornet Apr 1, 2019, 7:06 PM

#

I'm having a weird behavior with variables in a shader that are not declared inside the Properties block and are declared in the Subshader block, their values seem to not persist when certain conditions are met (for example tabbing out of the Unity Editor)

#

I have this variable on a shader uniform float _ArraySize; and I'm getting weird behavior when minimizing Unity or tabbing out to the desktop

#

Here's step by step what I do with that variable and what is happening afterwards
1. I click play on the Unity Editor and the application starts
2. On the Start method of an external script I set it to 5 myMaterial.SetFloat("_ArraySize", 5)
3. On the fragment shader I use the variable to check if it matches either value 0 or value 5
4. _ArraySize matches 5, fragment shader works as intended
5. I tab out of Unity or click on my second screen or minimize it. Then I come back into Unity
6. _ArraySize matches 0 and as a result the shader stops working

#

why are those variables being reset to 0 whenever I minimize Unity? It doesn't happen when I put that float on the Properties block but I'm also using arrays which are not supported as Properties in shaders, so I loose all the data of the arrays whenever I tab out of Unity

somber bolt Apr 1, 2019, 7:09 PM

#

Anyone know if there is a way to modify a Shadergraph file with actual Shader code? ie I need my Shadergraph file to have stencil functionality and add this to Properties

[Enum(Equal, 3, NotEqual, 6)] stest("Stencil Test", int) = 3

and this to every SubShader

Stencil {
Ref 1
comp[stest]
}

devout quarry Apr 1, 2019, 7:10 PM

#

@frigid zinc water shader starting to look pretty

#

📎 mNodNKD6cj.mp4

#

the sine wave is kinda boring though

broken field Apr 1, 2019, 7:37 PM

#

add more sines with different times

devout quarry Apr 1, 2019, 7:39 PM

#

yes! Gonna look into 'gerstner' waves too

#

I see that term a lot when it comes to water

broken field Apr 1, 2019, 7:40 PM

#

that's just a technique to make waves peak instead of hump when they join

#

better for ocean?

#

https://www.youtube.com/watch?v=5-XW_qev5dg

YouTube

Alexander Sannikov

Gerstner wave approximation

I made this simple demo to play with different parameters of Gerstner waves to find out what they are capable of and what they are not.

▶ Play video

fervent tinsel Apr 1, 2019, 7:41 PM

#

https://catlikecoding.com/unity/tutorials/flow/waves/

broken field Apr 1, 2019, 7:41 PM

#

The vid merely shows the effect it has

fervent tinsel Apr 1, 2019, 7:42 PM

#

https://giant.gfycat.com/PertinentSpitefulCrane.webm

Gfycat

catlikecoding

Gerstner Wave Correct Normals

▶ Play video

#

you mean that?

broken field Apr 1, 2019, 7:42 PM

#

I assume alex means that effect, but might not know it's for that effect :D

#

it's not so useful for smaller bodies of water and can be skipped i think

#

though it is nice isnt it?

devout quarry Apr 1, 2019, 7:44 PM

#

yeah I saw gerstner in the catlikecoding article too

#

I'll try some sines with offsets first

#

and for refraction

#

can it be as simple as offsetting the UV's at random spots?

#

like squeezing and stretching them

broken field Apr 1, 2019, 7:45 PM

#

refraction is a built in feature

#

(if HDRP)

devout quarry Apr 1, 2019, 7:46 PM

#

LWRP

broken field Apr 1, 2019, 7:46 PM

#

just read the buffer it should be present before transparent pass

#

(opaque buffer)

#

and blend that tex

frigid zinc Apr 1, 2019, 7:59 PM

#

@devout quarry I think you broke reddit 😛 : https://www.reddit.com/r/Unity3D/comments/b80wyk/this_subreddit_recently/

devout quarry Apr 1, 2019, 8:01 PM

#

haha, yeah it was posted few hours after I did

#

I like the meta posts on that subreddit

frigid zinc Apr 1, 2019, 8:01 PM

#

saw your posts, I recognized your demo scene lol

brazen comet Apr 1, 2019, 9:23 PM

#

Upgraded planet shader and it's custom editor I made from my old package in the store : https://i.imgur.com/7FBPEjL.jpg

It's 1 mesh / 1 material , with a 2 pass shader made with amplify. There is no directional or point light in scene , only a Game Object to set the illumination direction, all the shader is Emissive and should run on mobile (exept for the ultra high res cloud texture , it will need to be downsized)
This update will reach the store in at least 2 weeks, not before.

Imgur

frigid zinc Apr 1, 2019, 9:25 PM

#

looks gorgeous.

brazen comet Apr 1, 2019, 9:27 PM

#

Thank you , I've put all my heart in it.

broken field Apr 1, 2019, 10:49 PM

#

that's a very nice planet shader, the best

mellow falcon Apr 2, 2019, 4:25 AM

#

I can't seem to find the document to convert existing custom shader to the new SRPs, does they exists yet?

broken field Apr 2, 2019, 4:36 AM

#

yeah click the documentation link in package manager for the package

#

but conversion is not realistic outside of shader graph

#

add a custom function node if you need more control

grand jolt Apr 2, 2019, 7:09 AM

#

Hello,
I'm trying to fake spot a light in a 2D game that influence a portion of the screen depending of it's position and it's range. It works-ish but I'm not quite satisfied because my game is not exactly top-down so the light shouldn't be exactly a circle. So far my shader just compute the distance of the pixel with the light position and if it less than the light range the computation continue. So the area effect is always a circle.
Is it possible, having a global angle that represent my game "perspective" to compute/know how a "circle" would looks like and be able to know if a pixel is inside this shape ?

still carbon Apr 2, 2019, 7:26 AM

#

@stark hornet that's pretty strange, I know that when you place it in properties, that serializes the values on the material so they can get re-applied whenever. Perhaps if it's not a global set variable it loses that data when context is lost? I've had the opposite experience with global texture arrays where unity doesn't like the size changing on them unless you've restarted unity itself!

mellow falcon Apr 2, 2019, 9:06 AM

#

@broken field does you mean this: https://docs.unity3d.com/Packages/com.unity.render-pipelines.lightweight@5.10/manual/upgrading-your-shaders.html. I also checked the other related packages, this is the closest I could find, but is only talk about built-in shader

grand jolt Apr 2, 2019, 9:44 AM

#

Images can talk better than words, so here more "illustrated" explantions : https://forum.unity.com/threads/shader-graph-drawing-an-ovale-based-on-the-distance-between-two-points.654499/

Unity Forum

Shader graph : drawing an ovale based on the distance between two ...

Hi !

I’m pretty new to shader graph, and to shaders in general. I'm stuck in a math problem and I don’t have a clue on how to manage it.. Here’s the...

#

any help is welcome.

#

😃

amber saffron Apr 2, 2019, 10:33 AM

#

I answered, with blindly writen pseudocode

#

But basically, an ovale is a sqashed circle, so you just have to scale the difference of the two vectors on one axis, and then compute the distance.

#

That's way more effective then trying to do something based on the angle.
On the other side, if you need non axis oriented elipses, that's getting a bit more complicated.

mental sentinel Apr 2, 2019, 10:54 AM

#

+1 @amber saffron I would say the same answer

grand jolt Apr 2, 2019, 10:59 AM

#

@amber saffron thanks ! Would it be possible to compute the squash factor depending of the light range and the "angle" ?

amber saffron Apr 2, 2019, 11:00 AM

#

Yes, you can do that in c#. In fact, only the angle is needed here, as you want to scale an axis to have a "non uniform circle"

mental sentinel Apr 2, 2019, 11:01 AM

#

if you have more than one light it gets complicated

#

you will need arrays I guess

grand jolt Apr 2, 2019, 11:03 AM

#

Yes. That' an other problem. So far they are declared hard-coded in the shader.

amber saffron Apr 2, 2019, 11:06 AM

#

Remember my advice about making a "compute light" node for a single light, and use multiple of them and a texture/array to pass the light values ?

grand jolt Apr 2, 2019, 11:09 AM

#

Yes I do remember. Not sure how to create the light node, the API about custom node are about to change from what I have read. But I thought it would be possible to "pack" all my current "compute light" node into a subgraph and having multiple of those and feed them with arrays. Each arrays would represent a same type of data, one for light position, one for light range, one for light colors etc. Does that make sense ?
Extra question: is it possible to pass textures through array ? I did not find a way to achieve that?

amber saffron Apr 2, 2019, 11:11 AM

#

I was more talking about a subgraph for the light node.

#

I'm a bit confused right now if Shadergraph already has an input for float1/2/3/4/matrix array (can you confirm?).
If not, you can use a single texture as input instead of an array, as basically, a texture is an array of pixels/colors, and those a simply vector4 datas.

grand jolt Apr 2, 2019, 11:15 AM

#

yes, there is those arrays !

#

So what you meant is that I can write textures data in array in order to pass all of them into the shader ?

amber saffron Apr 2, 2019, 11:17 AM

#

No, I had the other way around in my head.

grand jolt Apr 2, 2019, 11:19 AM

#

Meaning ? The goal of those textures is to define for each light a different "ramp texture" so I thought that each "light" would know its texture and at initialisation send all those textures int the shader to feed all light sub-graph.

amber saffron Apr 2, 2019, 11:22 AM

#

Well, you don't have texture array for the moment, so you have to send it to the shader in an other way.
Since your can't use global shader properties (for the moment), you'll have to use a shared texture.
One thing could be to manipulate the texture in c# to store all the data you want.
For example, with a 130x20 pixels texture, you could store in each line of pixels :

1 pixel for the position
1 pixel for the rotation or other data (you have 4 values)
128 pixels for the color ramp

And thus, store 20 lights, here.

vocal narwhal Apr 2, 2019, 11:22 AM

#

1 pixel for position and rotation 😉

#

and 1 spare value!

amber saffron Apr 2, 2019, 11:23 AM

#

For pure 2D, yes.

grand jolt Apr 2, 2019, 11:26 AM

#

I'm not sure we are talking the same thing right here. I think arrays exist in shader graph so I thought to use them to send data to the shader. When I was talking about textures I meant a real texture used by the shader to compute the "ramp" effect. So like the position or the color, the texture is a "light" property. So I need (if possible) to set this property two.
But what you are saying, I guess, is that if arrays (float1 etc.) does not exist shader graph side, I should use a texture2D property in the shader in order to write required data inside it.

#

Am'I correct ?

amber saffron Apr 2, 2019, 11:28 AM

#

That what I said.

#

Correct.

grand jolt Apr 2, 2019, 11:57 AM

#

Tahnks !

#

Thanks

grand jolt Apr 2, 2019, 12:40 PM

#

@amber saffron Ok, so I just checked and there is not array float or vector in the shader graph. Surprisingly there is a Texture2D array property but not sure I can use it.

So I need to go the way you proposed. I want to be sure I get it right. Let's say I have a "fake light" script that I put on every object I want to act like a fake light. This script would have properties such as:

range
color
ramp texture (1x128)

Then I would have a FakeLikeController script that will retrieve all FakeLight scripts. t That script would have a Texture2D property, for example 10x123 and every frame it will retrieve fake light position and properties and write them inside its texture2D and then set that texture in the Shader ? Am'I right ?

I guess I can monitor what have changed between two frame for not having to re-write all the controller texture data.

stark hornet Apr 2, 2019, 1:02 PM

#

@still carbon from what I've been reading seems like it's possibly a serialization issue with Unity for shader variables declared outside the Properties block. It seems certain event changes like OnApplicationFocus, OnApplicationPause and probably a bunch of others are causing the shader variables to lose their values

#

I guess Unity assumes those values are meant to be set every frame, which Im avoiding to save performance so I guess I will have to manually set them again whenever something causes them to lose their values. Any other variables I will place them on the Properties block, but with arrays I can't

amber saffron Apr 2, 2019, 1:29 PM

#

@grand jolt Yes, that's what I had in mind

grand jolt Apr 2, 2019, 1:32 PM

#

Thanks ! I will investigate that solution so.
Extra question: is it possible to "dynamically instantiate" sub-graph ? That would allow me to just have as much sub-graph as fake lights.

broken field Apr 2, 2019, 1:33 PM

#

Is it possible to access the current jitter of the camera in regular scripts or in shaders? I quite fancy jittering my alphatest amount each frame to see if it can improve AA

#

or maybe it doesn't matter much, who knows

amber saffron Apr 2, 2019, 1:34 PM

#

@grand jolt I don't think you can do that, sorry 😃

grand jolt Apr 2, 2019, 1:35 PM

#

I can imagine why.

#

but needed to ask 😃

amber saffron Apr 2, 2019, 1:36 PM

#

@grand jolt Also, your scripts that store datas per light, quick tip : you don't have to use a texture for the ramp, just use a gradient, and sample it when creating the texture in the "global" script 😃

grand jolt Apr 2, 2019, 1:36 PM

#

Got it ! thanks !

devout quarry Apr 2, 2019, 2:17 PM

#

anyone got the custom function node to work in shader graph?

#

specifically when referring to another file

#

@broken field

#

I see you used them?

broken field Apr 2, 2019, 2:25 PM

#

I briefly dabbled but probably won't be enough to give you great help. I liked your tweet on water, cool tip :D

devout quarry Apr 2, 2019, 2:25 PM

#

thank you 😃

amber saffron Apr 2, 2019, 3:04 PM

#

That might help you in the near future @grand jolt (and possibly a lot of other people) :

📎 unknown.png

grand jolt Apr 2, 2019, 3:05 PM

#

Yep. Thanks !

amber saffron Apr 2, 2019, 3:06 PM

#

It's already in the github repository, and will be comming in next package release for 2019.2

devout quarry Apr 2, 2019, 3:11 PM

#

the documentation lacking immensely though 😢

fervent tinsel Apr 2, 2019, 3:25 PM

#

that is already in 5.10

#

sg custom function node that is

#

@devout quarry

amber saffron Apr 2, 2019, 3:26 PM

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wow, how did I miss that

fervent tinsel Apr 2, 2019, 3:26 PM

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I think it might have been in 5.8 already

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but 5.10 definitely has it

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because I'm using it here https://github.com/0lento/OcclusionProbes/tree/2019.1-hd-sample

GitHub

0lento/OcclusionProbes

Unofficial Occlusion Probes Package, requires Unity 2019.1+ - 0lento/OcclusionProbes

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@devout quarry you can see file example here: https://github.com/0lento/OcclusionProbes/blob/package.hd/Include/OcclusionProbes.cginc

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oops, fixed the link now

broken field Apr 2, 2019, 3:28 PM

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https://forum.unity.com/threads/hdrp-refraction.618193/#post-4384027

Unity Forum

HDRP + Refraction

Hi,

I am having hard time achieving refraction using HDRP Lit shader. First for transparent objects, Surface type needs to be "Transparent" & Blending...

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just highlighting an issue with latest 6.6

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hdrp reflection bug

fervent tinsel Apr 2, 2019, 3:29 PM

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@devout quarry and here's example on how you can use it on SG itself:

📎 unknown.png

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the screenshot is actually from different project so don't wonder about the Assets path on that one

devout quarry Apr 2, 2019, 3:30 PM

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.cginc file 😮

fervent tinsel Apr 2, 2019, 3:30 PM

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the one I linked was in package

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well, that's just what I named it

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could be anything

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hlsl

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shader

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etc

amber saffron Apr 2, 2019, 3:31 PM

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*.magic

fervent tinsel Apr 2, 2019, 3:31 PM

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I don't know what is the preferred thing there

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yeah, magic would work as well 😄

devout quarry Apr 2, 2019, 3:31 PM

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and can you change the 'custom function' name?

fervent tinsel Apr 2, 2019, 3:31 PM

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in SG graph?

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no

devout quarry Apr 2, 2019, 3:31 PM

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too bad

fervent tinsel Apr 2, 2019, 3:31 PM

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it'll always read "custom function

devout quarry Apr 2, 2019, 3:32 PM

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tyvm for the help, gonna try this out immediately 😃

fervent tinsel Apr 2, 2019, 3:32 PM

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well, it's not really that bad

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just do what I did there

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put the whole thing in subgraph

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and use it as new node

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it's reusable then

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recent SG versions support subgraph nesting so you could have as many nested as you want

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it's no issue

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there is one issue with the file thing that one has to be aware though

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you can't include same file on multiple different custom function nodes

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like, if you want to have multiple functions you call in same include file, that's broken atm

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I have filed a bug report for it but there's no ETA for fix

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so, if you need something like that today, you just have to have new shader include file for each custom function node

devout quarry Apr 2, 2019, 3:34 PM

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yeah so why would I use custom function nodes if I can use subgraphs?

fervent tinsel Apr 2, 2019, 3:34 PM

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this is why I ended up with this mess https://github.com/0lento/OcclusionProbes/tree/package.hd/Include

GitHub

0lento/OcclusionProbes

Unofficial Occlusion Probes Package, requires Unity 2019.1+ - 0lento/OcclusionProbes

devout quarry Apr 2, 2019, 3:34 PM

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Can't I just make the 'custom function' through nodes

fervent tinsel Apr 2, 2019, 3:34 PM

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you can

amber saffron Apr 2, 2019, 3:34 PM

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loops

fervent tinsel Apr 2, 2019, 3:34 PM

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but you can't do everything in SG

devout quarry Apr 2, 2019, 3:34 PM

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ah I see

fervent tinsel Apr 2, 2019, 3:34 PM

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or some things are just needlessy complicated

devout quarry Apr 2, 2019, 3:34 PM

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Gonna try out both

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well for basic math operations SG is such a hassle

fervent tinsel Apr 2, 2019, 3:35 PM

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in my case, I just wanted to read the public variable, SG subgraphs don't support it

broken field Apr 2, 2019, 3:35 PM

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https://tenor.com/view/magic-shia-labeouf-snl-skit-fingers-gif-4860090

Tenor

devout quarry Apr 2, 2019, 3:35 PM

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a lot of nodes instead of a one-liner

fervent tinsel Apr 2, 2019, 3:35 PM

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if you'd do the same on SG only, you can only get global parameters from the main graph, not from subgraphs

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I wish it wasn't so

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but you can work around it with the file include

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also

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SG hasn't exposed all shader commands

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so if you need something that's not there, no biggie, put custom function node and write the shader code for it yourself

devout quarry Apr 2, 2019, 3:38 PM

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I think I'll prefer custom function nodes over subgraphs

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with custom nodes I'll learn to code real shader code

broken field Apr 2, 2019, 4:18 PM

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not same thing

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you put the custom node inside a subgraph.

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the subgraph is then shared across all your other graphs if you choose

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think of it as a container not just for nodes but also for hlsl

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its not a "hider" but a "re-user"

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because sub graphs become assets in the project

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It sure becomes handy then to just add that subgrah like a regular node in any other shader you do...

echo badger Apr 2, 2019, 4:33 PM

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I have been trying to figure out how to do a foliage interaction shader using Shader graph. The part I am unsure of how to do is how to get the position of the object that would be pushing the vertices.

fervent tinsel Apr 2, 2019, 4:33 PM

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@echo badger you know unity does have a demo for that

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oh wait it was on vfx samples

echo badger Apr 2, 2019, 4:34 PM

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It does?

broken field Apr 2, 2019, 4:35 PM

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for vegetation bending at it's simplest, make a vertex shader that moves verts away from an xyz position you pass in.

frigid zinc Apr 2, 2019, 4:36 PM

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for shaders your character script should set a global shader variable that contains the character's current position.

broken field Apr 2, 2019, 4:36 PM

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you do this by getting a direction by subtracting the vert world pos from the pos you pass in

frigid zinc Apr 2, 2019, 4:36 PM

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https://docs.unity3d.com/ScriptReference/Shader.SetGlobalVector.html

broken field Apr 2, 2019, 4:36 PM

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yeah start there... then solve the additional problems as they crop up

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dont try to solve the entire thing first, just get verts reacting first

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so get it reading a position you pass in first

frigid zinc Apr 2, 2019, 4:37 PM

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the shader can then read the variable and know the character position.

echo badger Apr 2, 2019, 4:37 PM

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Thanks hippo. But I figured that was the basic idea. I was just not sure how to get the position though.

broken field Apr 2, 2019, 4:38 PM

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As ceebee mentioned above

frigid zinc Apr 2, 2019, 4:38 PM

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I just told you how

echo badger Apr 2, 2019, 4:38 PM

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yes thank you.

broken field Apr 2, 2019, 4:39 PM

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use a string for now, give it an imaginative name

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"MyDogsButtAsHeScratchesThatItch"

frigid zinc Apr 2, 2019, 4:39 PM

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heh

broken field Apr 2, 2019, 4:39 PM

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or "PlayerPos"

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when you can access it inside shader you can move onto grabbing the world-space position of a vertex

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you could prototype this in c# first

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to get he maths right

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if you want

frigid zinc Apr 2, 2019, 4:41 PM

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https://twitter.com/i/status/1014226452378775557

Joyce[MinionsArt] (@minionsart)

Interactive grass using an array of object positions! #gamedev #unity3d #vfx
Shader code + script for multiple objects in first reply :)

More tips and shaders >> https://t.co/FqAsMb9Plg https://t.co/7LnXmCs6PI

Retweets

772

Likes

3091

▶ Play video

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mini-tutorial

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Object Position would be your character position

echo badger Apr 2, 2019, 4:42 PM

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Yeah, that is a good tutorial.

stone sandal Apr 2, 2019, 4:42 PM

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minion's art is great for bite-sized info chunks, she's started porting her shader stuff into shader graph too

echo badger Apr 2, 2019, 4:44 PM

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Using Shader.SetGlobalVector. How would I access it then in shader graph? Would I use the property name from setglobal as the name in reference in shader graph?

amber saffron Apr 2, 2019, 4:44 PM

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If i'm not wrong, if you declare a property with that name in the blackboard, you can access it

stone sandal Apr 2, 2019, 4:45 PM

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declare property, make sure that the "exposed" check box in disabled, and name the reference name with the property name

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will only work if it not exposed on the blackboard

echo badger Apr 2, 2019, 4:47 PM

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Got it. Is there a better way to do this if I want it to react to quite a few different objects and not just the player?

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For example NPCs

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There has to be a better way than just have like 1000 properties

frigid zinc Apr 2, 2019, 4:48 PM

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you can set a global array

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instead of just a single vector

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have the shader iterate over that

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but will be more complicated

echo badger Apr 2, 2019, 4:49 PM

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SG doesn't seem to support arrays right now

frigid zinc Apr 2, 2019, 4:49 PM

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her tut mentions multiple objects as well

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oh well, then I dunno. odd they wouldn't support that

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might could take it 99% of the way with SG

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then add that part in by hand

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or wouldn't custom nodes work?

echo badger Apr 2, 2019, 4:51 PM

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I remember a overview article about a similar shader mentioning drawing the interactable objects onto a separate texture

frigid zinc Apr 2, 2019, 4:51 PM

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if you scroll up to around 8AM Remy and 0lento were talking about custom nodes in shadergraph

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lets you insert raw HLSL into the node graph

devout quarry Apr 2, 2019, 4:54 PM

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📎 chrome_uZ2ML2omiW.png

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📎 Discord_bwqhu7AoFr.png

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I have the relevant images screenshotted here 😃

echo badger Apr 2, 2019, 5:30 PM

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Hey thanks.
I was looking more at the idea of drawing objects on to a texture and using that, for the vertex displacement. Looks like I would need to use a grab pass and an ortho camera, probably with render layers only rendering the objects that can interact with the foliage? Though I am not sure how to get from the texture to using it for the actual interaction part.

devout quarry Apr 2, 2019, 6:16 PM

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man I suck at creating these custom nodes lol

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will take some time

stark hornet Apr 2, 2019, 6:20 PM

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I'm having trouble using an array in my shader. I have this array (declared on the main body of the pass): uniform float4 _WorldPositions [100];

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I'm trying to modify it in the vertex program vertexOutput vert(vertexInput input) {_WorldPositions[i] = mul(_MyMatrixArray[i], worldPos); }

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and then use the result in the fragment programfloat4 frag(vertexOutput input) : COLOR { if (length(_WorldPositions[i].xyz) > 0.5) }

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But it doesn't seem to give any result. It works fine if I declare the array in a struct like this and then pass it through the vertex and fragment programs

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float4 _WorldPositions [100] : TEXCOORD1;

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But that limits the size of the array to 32, if I exceed it it gives me this error ps_4_0 input limit (32) exceeded

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any ideas why I am not able to "modify" the values of the array on the vertex program and use the result in the fragment program if I define it on the main body of the pass instead of inside a struct?

stark hornet Apr 2, 2019, 8:16 PM

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*** Nevermind it seems that I glanced over the fact that "uniform" variables cannot be changed inside a shader, they need their values to be initially provided by an external source and remain constant throughout the execution of the shader

broken field Apr 2, 2019, 8:57 PM

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uniform and varying

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the 2 kinds

stark hornet Apr 2, 2019, 9:42 PM

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@broken field does HLSL have "varying" variables?

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what exactly are they?

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and how are they used in Unity?

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can't find any info on that

still orbit Apr 2, 2019, 9:44 PM

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interpolators are varyings

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for a start

stark hornet Apr 2, 2019, 9:45 PM

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oh so the variables defined inside a struct with semantics like POSITION, COLOR, TEXCOORD, etc?

still orbit Apr 2, 2019, 9:45 PM

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in the vertex to fragment struct yes

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those are varyings

stark hornet Apr 2, 2019, 9:51 PM

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I see

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I have a question related to that, regarding how data is passed to the fragment shader

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If I have this conditional on the fragment shader using an array of float4 with the semantic TEXCOORD1 that is defined on the Vertex to Fragment struct(v2f)

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if (length(input._WorldPositions[i].xyz) > 0.5)

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will it work in exactly the same way if instead of that input._WorldPosition[] I provide the data from an outside script?

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instead of having it as an interpolator on the v2f struct?

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because I just read this on the Unity docs: The values output from the vertex shader will be interpolated across the face of the rendered triangles, and the values at each pixel will be passed as inputs to the fragment shader .

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and it kinda made me doubt about what I'm trying to do

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My initial assumption is that it will work, because all I need is to make this calculation outside the shader, and then use the resulting float4 on the fragment shader:

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output._WorldPositions[i] = mul(_MyMatrixArray[i], worldPos);

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multiplying a matrix by a float4

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but there's so many shader concepts I'm not familiar with that sometimes I make assumptions based on my lack of experience... so I don't know what to assume anymore 😅

still orbit Apr 2, 2019, 10:39 PM

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so youre setting this data from C# either way?

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just read it in the fragment shader, interpolators have a cost

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and should only be used to move vertex attribute data into fragment

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so for example if you need clip space and world space position in fragment

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youll calculate both those in vertex and use two interps

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because theres 0 point calculating the world pos per fragment (the result will be the same) and the interp is likely cheaper than the ALU cost of doing it in fragment

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oooh sorry I didnt read your snippet

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yea yours is a murkier case and depends on the rest of the shader complexity

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but likely its worth doing it in vertex

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otherwise youll be doing arr.Length amount of muls per fragment. Likely pretty costly.

stark hornet Apr 2, 2019, 10:54 PM

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@still orbit as of now I have a shader that discards pixels based on their world positions, I supply an array of matrices from external objects into the shader via a C# script, I take each of those matrices in the array and multiply them with the world positions in the vertex program

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then I store the results in an array of float4 and pass that into the fragment shader, which performs discards based on that

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for now I use the array as TEXCOORD1 on the vertex to fragment struct

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but that limits a lot the size of the array I can use

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so I'm trying to do that externally to support more items in the arrays

still orbit Apr 2, 2019, 10:55 PM

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whats your target platform?

stark hornet Apr 2, 2019, 10:56 PM

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Windows

still orbit Apr 2, 2019, 10:56 PM

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use a read/write structured buffer instead

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itll limit your minimum target to (i think) shader model 4.6?

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but should be fine for your case, just a general nono on mobile

stark hornet Apr 2, 2019, 10:57 PM

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Thanks for the advice! I don't know much about buffers tho

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any specific info on what I should research?

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is that a "compute buffer" ?

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https://docs.unity3d.com/ScriptReference/ComputeBuffer.html

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I googled "read/write structured buffer" and most of the results seem to be about compute buffers

still orbit Apr 2, 2019, 10:59 PM

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hold on let me find you an example

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its not very documented

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https://github.com/Verasl/BoatAttack/blob/release/2019.1/Packages/com.verasl.water-system/Shaders/GerstnerWaves.hlsl

GitHub

Verasl/BoatAttack

Demo Project using the Lightweight Render Pipeline from Unity3D - Verasl/BoatAttack

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ergh, this isnt RW

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its kinda complicated and i dont have any info at hand :/

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gonna need some serious googlin'

stark hornet Apr 2, 2019, 11:03 PM

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yeah it seems kind of like a weird topic for a beginner like me

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any info on that to get me started is greatly appreciated tho! 😃

frigid zinc Apr 2, 2019, 11:07 PM

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https://docs.microsoft.com/en-us/windows/desktop/direct3d11/direct3d-11-advanced-stages-cs-resources

New Resource Types - Windows applications

Several new resource types have been added in Direct3D 11.

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https://www.gamedev.net/forums/topic/652939-rwstructuredbuffer-read-and-write/

GameDev.net

RWStructuredBuffer read and write ?

Hello I have a little question about the UAVs in directx. I read some explanations about UAVs but there are always 2 types of buffers for input and output in the examples. For my implementation I need a buffer that is only used in the shaders, so I use a pixel or compute shad...

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these both seem to talk about structured buffers

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https://docs.microsoft.com/en-us/windows/desktop/direct3dhlsl/sm5-object-rwstructuredbuffer

RWStructuredBuffer - Windows applications

A read/write buffer that can take a T type that is a structure.

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but it does seem to be pretty esoteric

stark hornet Apr 2, 2019, 11:08 PM

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it might be worth the read

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thx for the links

still orbit Apr 2, 2019, 11:08 PM

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yea its not exactly friendly documentation 😛

stark hornet Apr 2, 2019, 11:17 PM

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since we are talking about variables in HLSL shaders... I wonder, is there a limit to how many variables I can put on the Properties block of a shader?

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can't test that until tomorrow

still orbit Apr 2, 2019, 11:17 PM

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I think there is, but i think its like 256 or something ridiculous

stark hornet Apr 2, 2019, 11:17 PM

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well.. if it's 256 I could maybe take advantage of that

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but I assume putting that many could cause my shader to perform worse?

still orbit Apr 2, 2019, 11:18 PM

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ok youre not talking about properties block?

stark hornet Apr 2, 2019, 11:19 PM

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yes

still orbit Apr 2, 2019, 11:19 PM

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thats just the block at the top where they assign shaderlab properties to uniforms

stark hornet Apr 2, 2019, 11:19 PM

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im talking about the block at the top of the shader

still orbit Apr 2, 2019, 11:19 PM

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i dont see how thatll help you

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you dont need to use that to set data from C#

stark hornet Apr 2, 2019, 11:19 PM

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just asking in case I can experiment with that to see how that behaves in the shader

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but I guess that would be pretty much the same as having a uniform array instead of 100 variables in the Properties block

still orbit Apr 2, 2019, 11:20 PM

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yea you dont need them in the properties block

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that just links material data to uniforms

stark hornet Apr 2, 2019, 11:21 PM

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hmm I see

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I wonder if I could provide float4 from a C# script and interpolate them manually in that script before passing them to the fragment shader...

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I still don't fully understand how the data output from the vertex shader gets interpolated for the fragment shader

still orbit Apr 2, 2019, 11:24 PM

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its part of the GPU pipeline

stark hornet Apr 2, 2019, 11:24 PM

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in the sense as, does ALL data get interpolated or just positions?

still orbit Apr 2, 2019, 11:24 PM

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all data you put into the v2f struct gets interpolated

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the GPU pipe knows where each fragment is in relation to the three verts of its triangle

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so it linearly interpolates all the data in that struct between the vertices

stark hornet Apr 2, 2019, 11:25 PM

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does it interpolate in clip space or world space?

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I assume clip

still orbit Apr 2, 2019, 11:25 PM

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not in any space

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its just data

stark hornet Apr 2, 2019, 11:26 PM

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oh

vocal narwhal Apr 2, 2019, 11:26 PM

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in the space of the triangle

still orbit Apr 2, 2019, 11:26 PM

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the fragment position is relative to the triangle

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so yea, triangle space? lol

vocal narwhal Apr 2, 2019, 11:26 PM

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which isn't a space in the shader sense 😛 but yeah

still orbit Apr 2, 2019, 11:26 PM

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yea, explains the concept though i guess 😛

stark hornet Apr 2, 2019, 11:27 PM

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thanks for the clarification 🙃

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do vertex and fragment programs accept more than 1 struct as input?

still orbit Apr 2, 2019, 11:31 PM

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yes

stark hornet Apr 2, 2019, 11:32 PM

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so could I technically create a bunch of structs in the following fashion and pass them through the vertex and fragment programs?

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float4 _WorldPositions [10] : TEXCOORD1;
};```

still orbit Apr 2, 2019, 11:33 PM

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theoretically yes but why?

stark hornet Apr 2, 2019, 11:34 PM

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because I'm trying to use an array of float4 with a size of let's say 500

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so would it be possible to divide that into a bunch of structs each one with an array with the maximum number of interpolators permitted?

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or does the shader complain about max interpolators in the shader overall?

still orbit Apr 2, 2019, 11:34 PM

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woaaaahhhh

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thatll never work

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you need to find a different way 😛

stark hornet Apr 2, 2019, 11:35 PM

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haha yeah I guess not

still orbit Apr 2, 2019, 11:35 PM

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even if it compiles that shader will be your entire frame budget 😛

vocal narwhal Apr 2, 2019, 11:35 PM

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sounds fun 😛

stark hornet Apr 2, 2019, 11:37 PM

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well if my GPU explodes I won't say that you didn't warn me xD

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thanks for the help anyways guys! I think I still need to do more research on how to use arrays of data in shaders efficiently

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I will pray to the shader gods for their blessing 🙏🏽

broken field Apr 3, 2019, 12:07 AM

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nvidia cg brotherhood

grand jolt Apr 3, 2019, 12:53 PM

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@amber saffron I'm trying to start to work with textures to store data, but I do not find how it is possible to read textures values inside Shader Graph. I need to iterate though each row and each column but did not find nodes that can do that. Am'I missing something ?

toxic mango Apr 3, 2019, 1:04 PM

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hey everybody, I'm trying to do rendertexture with camera, but I'm encountering a problem.

I'm working on AR scene where the background is drawn with a shader with

Tags { "RenderType"="Background" }

on a camera with clear flags set do Depth Only, and nothing is being rendered.

Do you know of any way to properly render everything, including Background? I can't have the stuff from shader obstructing 3D scene, as I'm trying to overlay AR objects on top of real world stuff.

toxic mango Apr 3, 2019, 1:20 PM

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btw, the scene looks good in the application itself, just rendering to texture doesn't work

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which is what puzzles me

devout quarry Apr 3, 2019, 1:57 PM

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in shader forge there is a 'refraction' slot in the master node

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is there something similar in shadergraph?

amber saffron Apr 3, 2019, 3:01 PM

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@grand jolt There's not magic to read texture value apart from using sampler and calculating your uvs 😃

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@devout quarry There's the index of refraction in the HDRP lit master node.

grand jolt Apr 3, 2019, 3:08 PM

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@amber saffron I do not understand, sorry. How can read specific pixel or range of pixels using a sampler ? Like you told me, I could have a row per light, first column position, second column color and 128 next column the ramp texture. How can I do/read that using a Sampler ?

amber saffron Apr 3, 2019, 3:09 PM

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Let says you want to read the value of the bottom left pixel in a texture of 128x16. You need to sample the texture at the UV coord : 0.5/128 , 0.5/16

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And generaly speaking, to sample a single pixel the uv coord is :
x = ( 0.5 + pixel.x ) / size.x
y = ( 0.5 + pixel.y ) / size.y

grand jolt Apr 3, 2019, 3:11 PM

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ok. But that means to use a sample texture2D node with a sampler node for each pixel I want to read. So even for one light it means putting 130 x 2 nodes (at least) in the sahder graph

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that's crazy, I must be missing something here 😃

amber saffron Apr 3, 2019, 3:12 PM

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not so much no

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In the example we had the othe day, you'll need one sampler for the first pixel (position), one for the second (other datas), and one for the gradient.

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You don't need to sample all the pixels for the gradient, you just do it like a regular gradient texture (just add a small offset)

grand jolt Apr 3, 2019, 3:16 PM

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Hum, how ? what ? The ramp texture is meant to be used in the fake light subgraph, so this subgraph need that ramp texture.

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Actually it's used in the sub-graph to get the right pixel according to the computing distance. But maybe I can calculate that before the subgraph and then send it to to the sub-graph. Need to check that.

amber saffron Apr 3, 2019, 3:22 PM

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I'm getting confused with your confusion now 😄 I tought that you had one ramp texture per light.If not, then your light data texture can be much smaller

grand jolt Apr 3, 2019, 3:23 PM

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Ha ha

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yes, I have one ramp texture per light

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this ramp texture should be pass in a sub-graph in the shader

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so it means at some point to read 128 pixels

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Am'i right ?

amber saffron Apr 3, 2019, 3:25 PM

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But like I said, you don't have to pass one ramp per light, it could be store in the lights data texture.
And to sample the ramp, you don't need to sample all the pixels, you just sample a single one (with interpolation).
That's what you already did with the previous method, right? You don't sample each pixel of the ramp texture.

grand jolt Apr 3, 2019, 3:28 PM

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Now, I'm very confused :-)
Each ramp texture won't be a straight gradiant, there would be specific parts with different flat color in order to have a cartoon effect. So I don't think I can interpolate something.
In my previous method I just sampled one pixel, yes, but to sample that one pixel, in my sub-graph, the sub-graph needs to have the access to the ramp texture <- that is exactly what I don't know how to do.

amber saffron Apr 3, 2019, 3:39 PM

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I'm pretty sure you interpolate. Your ramp texture is set to linear interpolation right ? You sample in it by using the distance as UV.x (or something like that), and this value can be "between" pixels.

You can store the ramp in the light data texture. Like I said in my previous example, let say that for each row you have pixels 1 and 2 that store data, and the rests that store the ramp (ramp is unidimentional and doesn't need more than one pixel).
Then you can sample the ramp by doing this :

uv.x = lerp( 2.5/size.x, (size.x-0.5)/size.x, distance );
uv.y = ( 0.5 + lightIndex ) / size.y;

rampValue = SampleTexture( dataTexture, uv );

grand jolt Apr 3, 2019, 3:43 PM

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ok, so I compute the ramp value before the sub-graph. At least this is what I understand and it makes sense for me.

amber saffron Apr 3, 2019, 3:46 PM

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Yes

grand jolt Apr 3, 2019, 3:47 PM

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I'm relief to say that I'm not confused anymore 😅

amber saffron Apr 3, 2019, 3:47 PM

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Yay

grand jolt Apr 3, 2019, 3:48 PM

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Shaders really are a weird, strange and scary realm !

amber saffron Apr 3, 2019, 3:48 PM

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Naaah, it's fun !

grand jolt Apr 3, 2019, 4:00 PM

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I guess so 😃

#

If I want to really optimize memory, can I store 4 pixel of my ramp texture in one pixel of the shader texture ? My ramp texture is in grayscale, so RGB value are always equals and the alpha is always 1. So with one value I can re-create the whole pixel RGBA values. Does that make sense ?

amber saffron Apr 3, 2019, 4:03 PM

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It makes sense memory wise, but then you'll need to do some uv trick to still profit from the interpolation.

grand jolt Apr 3, 2019, 4:04 PM

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indeed

amber saffron Apr 3, 2019, 4:04 PM

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But honestly, I doubt that on such small texture size you should worry about memory

grand jolt Apr 3, 2019, 4:04 PM

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ok !

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So I will start with the "easy" first. Gonne be enough to my nerves !

amber saffron Apr 3, 2019, 4:05 PM

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Like, iven at highest precision (32 bits signed float per component), the data for 32 lights would be 0.5 MB

grand jolt Apr 3, 2019, 4:06 PM

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One last question : should I used one big texture or separates textures in order to not have to re-write and re-send unmodified datas ? For example, tramp textures won't change, they can be write and send just once in one specific big texture in the shader. So i could have one big texture for ramps and one big texture for positions and datas.

amber saffron Apr 3, 2019, 4:07 PM

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You could separate in multiple textures depending on the precision you need (float 32 for position data, and unorm (255 values) for color)

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And this also answers your previous question 😃

grand jolt Apr 3, 2019, 4:08 PM

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ha ha ! thanks 😃

devout quarry Apr 3, 2019, 4:34 PM

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does the view direction node act differently in HDRP than LWRP?

stark hornet Apr 3, 2019, 7:54 PM

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I'm trying to measure world distances in a shader, and I'm getting weird results with the distance() function in the shader

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distance(myGameObject, input.worldPos);

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this should return the actual world distances from each pixel to the origin of myGameObject, right?

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this are the actual results that I'm getting, on the left the actual world distance measured on a C# script and on the right the values I'm getting in the shader distance function

📎 shader_distance_function.png

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is there something I'm missing?

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here's how I calculate the fragment world position in the shader output.worldPos = mul(unity_ObjectToWorld, input.vertex);

frigid zinc Apr 3, 2019, 8:11 PM

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well remember that worldPos is going to be the location of the vertex, not the object.

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so an object might be at 1,1,1 but lets say the object is a cube, and the pivot is at geometric center, the vertices will be at 0.5, 0.5, 0.5 etc

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assuming cube is 1 meter in scale

stark hornet Apr 3, 2019, 8:13 PM

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I was under the impression that when I pass that "worldPos" into the fragment shader the values get interpolated automatically

frigid zinc Apr 3, 2019, 8:14 PM

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it does

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but doesn't change the fact object location != vertex location

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if a cube is at 1,1,1 vertice X for instance will range 0.5 to 1.5

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and yes it will interpolate between that

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not sure how to visualize this for you

stark hornet Apr 3, 2019, 8:15 PM

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but it seems to actually return a consistant world position with that, even if it doesn't measure the EXACT world position

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because when I move, scale or rotate my object everything moves along with the object

frigid zinc Apr 3, 2019, 8:17 PM

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not sure then

stark hornet Apr 3, 2019, 8:17 PM

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correction, moving and rotatin matains, scaling does not

frigid zinc Apr 3, 2019, 8:17 PM

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It should move as the object moves

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unless it's local space to the object

stark hornet Apr 3, 2019, 8:18 PM

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one sec, I'll post giff

frigid zinc Apr 3, 2019, 8:18 PM

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well I G2G hopefully someone else can help

stark hornet Apr 3, 2019, 8:18 PM

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no worries 🙃

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📎 Fragment_World_Position_Test1.gif

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so It seems that output.worldPos = mul(unity_ObjectToWorld, input.vertex); is actually returning a consistent world position for each fragment

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but the distance() function on my frag shader does not return distances in real world space... they are kind of weirdly exponentially increased

still carbon Apr 3, 2019, 8:40 PM

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@stark hornet calculate in the vert output.worldCenter = mul(unity_ObjectToWorld, float4(0,0,0,1)); and then in frag do distance(input.worldCenter, input.worldPos); ?

stark hornet Apr 3, 2019, 8:42 PM

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@still carbon alright I'll test that out, gimme a sec

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@still carbon that acts just as if I put the "intersection" on the origin

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the distance function still measures with it's weird values

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which are the same as when using any other location in the world

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seems the closer to the origin the more innacurate the values are

rotund tusk Apr 3, 2019, 8:51 PM

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myGameObject is a float3? what is your expected behavior

stark hornet Apr 3, 2019, 8:52 PM

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I use an array of Float4 on a C# script and I populate it like this:

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intersectorsPositions[i] = intersectionsParent.transform.GetChild(i).transform.position;

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I want the distance() function on my shader to match the actual distance on the world space of the objects that I pass into the shader

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the closer to the point I pass into the shader (the origin of each myGameObject)

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the more inaccurate the value

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for example measuring on 100 world distance

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the shader measures almost 100

rotund tusk Apr 3, 2019, 8:54 PM

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so, as you scale the object, do you want the intersection positions to move too?

stark hornet Apr 3, 2019, 8:55 PM

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nope, I want the object holding the shader to not affect the shader at all

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the only thing that affects is the positions I feed into the shader as myGameObject, which are just empty gameobjects

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correction: they are positions taken from the transforms of empty game objects

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so they should not affect the shader at all when scaled or rotated, only when moved

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everything seems to be working as expected, except the values that the distance() function in the shader return

rotund tusk Apr 3, 2019, 8:58 PM

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ok. what if you do

stark hornet Apr 3, 2019, 8:58 PM

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a world distance of 0.1 equals a value of 0.005 in the shader. and a world distance of 100 equals almost 100 in the shader

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which is kinda weird to return that exponentially increased value

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I'll test what you posted, gimme a moment

rotund tusk Apr 3, 2019, 8:59 PM

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is this your own distance function?

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or hlsl/cg one

stark hornet Apr 3, 2019, 8:59 PM

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nope, the default HLSL distance function

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https://docs.microsoft.com/en-us/windows/desktop/direct3dhlsl/dx-graphics-hlsl-distance

distance - Windows applications

Returns a distance scalar between two vectors.

#

I also tested the Lenght function, with the exact same results

rotund tusk Apr 3, 2019, 9:01 PM

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how are you getting the actual values that distance returns?

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like the ones you showed in your table

stark hornet Apr 3, 2019, 9:02 PM

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measuring them in the scene with a C# script

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or placing small gameobjects as markers

rotund tusk Apr 3, 2019, 9:03 PM

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is that the GPU value though?

stark hornet Apr 3, 2019, 9:04 PM

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I'm debugging the distance that the shader gives with this in the fragment function:

#

{
    return col;
}```

rotund tusk Apr 3, 2019, 9:04 PM

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if you want to compare the distance from you empty gameobject to each pixel rendered on your clip gameobject

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ah

stark hornet Apr 3, 2019, 9:05 PM

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exactly

rotund tusk Apr 3, 2019, 9:05 PM

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how are you getting myGameobject out of your float array

stark hornet Apr 3, 2019, 9:06 PM

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here is the actual line of code in the shader: float dis = distance(_IntersectorsWorldPositions[0], input.worldPos);

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and I pass the values into the array in a c# script with this line:

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intersectorsPositions[i] = intersectionsParent.transform.GetChild(i).transform.position;

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that is an array of float4

rotund tusk Apr 3, 2019, 9:08 PM

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are the empty GOs the children of your clip GO?

stark hornet Apr 3, 2019, 9:08 PM

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yeah

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the parent is at 0,0,0

rotund tusk Apr 3, 2019, 9:08 PM

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(asking all these questions so i can better understand what you are trying to do)

stark hornet Apr 3, 2019, 9:09 PM

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no worries, ask all you want I will answer promptly 😛

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I'm gonna try the line with the square root that you posted above, brb

still carbon Apr 3, 2019, 9:10 PM

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does the result change at all if you do the object to world pos calculation in the fragment? (I can't imagine why it would, short of having vertex interpolators set... but)

rotund tusk Apr 3, 2019, 9:11 PM

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sqrt is probably the same output. you mind sharing your fragment function?

stark hornet Apr 3, 2019, 9:11 PM

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@still carbon how could I do that? same as in the vertex shader with a mul()?

still carbon Apr 3, 2019, 9:11 PM

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yeah

stark hornet Apr 3, 2019, 9:12 PM

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sqrt give a different output, and also the distance values seem to be not consistent with actual world distances

📎 2a91e015a657910390388843c7f66f37.png

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one sec I'll clean up the frag shader and I'll post it

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it's full of commented out code xD

rotund tusk Apr 3, 2019, 9:15 PM

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sorry it should have been

float3 disp = input.worldPos - myGameObject;
float dis = sqrt(  dot( disp, disp ) );

stark hornet Apr 3, 2019, 9:16 PM

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    float4 col = tex2D(_MainTex, input.uv);    
    float dis = distance(_IntersectorsWorldPositions[0], input.worldPos) - 1;    
    
    if(dis < _Threshold){
        return col;
    }
    discard;
    return float4(1,1,1,1);
}```

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@rotund tusk I'll try that, one momento

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OH SHIT

rotund tusk Apr 3, 2019, 9:17 PM

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you're subtracting 1 here?

float dis = distance(_IntersectorsWorldPositions[0], input.worldPos) - 1;

stark hornet Apr 3, 2019, 9:17 PM

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I think that is it!

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one sec I'll do more distance checks, but I believe you provided the answer

rotund tusk Apr 3, 2019, 9:18 PM

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distance should function the same as the code i posted

still carbon Apr 3, 2019, 9:18 PM

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yeah, seems like the -1 would be the culprit here

rotund tusk Apr 3, 2019, 9:18 PM

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that "-1" looks fishy haha

still carbon Apr 3, 2019, 9:19 PM

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has little effect around 100, but big effect when doing 0.1 compare

stark hornet Apr 3, 2019, 9:19 PM

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the -1 was just to make the values start at 0 instead of 1

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the results were pretty much the same, weirdly exponentially increased distance measures

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instead of lets say 101 it would be 100, and instead of 1.0055 it would be 0.0055

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but it was the same results

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BUT your code snipped solved it!

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float dis = sqrt(  dot( disp, disp ) );```

rotund tusk Apr 3, 2019, 9:20 PM

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so does

float3 disp = input.worldPos - _IntersectorsWorldPositions[0];
float dis = sqrt(  dot( disp, disp ) );

not behave like

float dis = distance(_IntersectorsWorldPositions[0], input.worldPos);

?

stark hornet Apr 3, 2019, 9:20 PM

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nope

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they have both "consistence" within themselves

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but the sqrt approach gives actual world distances

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I'm still puzzled by the behaviour of distance()

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can't wrap my mind around it

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it should be the same as your code snippet

rotund tusk Apr 3, 2019, 9:23 PM

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yathis is weird. distance should be doing a sqrt. it should end up compiling to the same instructions

stark hornet Apr 3, 2019, 9:23 PM

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hmmm...I've seen people use distance with a return type of vector(float3) instead of scalar(float)

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could that be it?

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Im using a return type of float

atomic echo Apr 3, 2019, 9:24 PM

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Return type of hlsl distance is scalar.

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https://docs.microsoft.com/en-us/windows/desktop/direct3dhlsl/dx-graphics-hlsl-distance

distance - Windows applications

Returns a distance scalar between two vectors.

stark hornet Apr 3, 2019, 9:25 PM

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here's an example of code from Minionsart (posts a bunch of shader tutorials on twitter) with distance() returning a vector

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float3 sphere = 1 - saturate(dis / _Radius);

 float3 sphereNoise = noisetexture.r * sphere;```

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don't know what that code actually does, I haven't tested that

rotund tusk Apr 3, 2019, 9:26 PM

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probably makes use of parallel computations

stark hornet Apr 3, 2019, 9:26 PM

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https://pastebin.com/FiDzFixp here's her full shader code

Pastebin

ToonLitDissolveWorldSpace.shader - Pastebin.com

rotund tusk Apr 3, 2019, 9:26 PM

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gpu might do that already but having dis be float3 and using it in the following computations enforces that

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so the components for sphere and sphereNoise are evaluated simultaneously

stark hornet Apr 3, 2019, 9:27 PM

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that code at the end does this:

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o.Albedo = resultTex;```

rotund tusk Apr 3, 2019, 9:28 PM

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float3 distance = distance() probably maps the scalar to each component. like

float3 dis = distance(...).xxx

stark hornet Apr 3, 2019, 9:28 PM

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so I guess the results of all the calculations with those vectors end up with each .x.y.z on the albedo values

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I see

still carbon Apr 3, 2019, 9:29 PM

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distance() seems consistent 🤷 https://i.gyazo.com/530c65385718a4221beb9f7200045789.mp4

▶ Play video

stark hornet Apr 3, 2019, 9:29 PM

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hmmmm

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strange

rotund tusk Apr 3, 2019, 9:30 PM

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using float3 will make use of SIMD unstruction sets

atomic echo Apr 3, 2019, 9:30 PM

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Yeah apparently HLSL can auto-promote a scalar to a vector.

#

Back to your original question... I don't know how distance() is screwing up... but maybe the inputs are confused about your vector size? Like maybe you're accidentally inputting float4s instead of float3s?

rotund tusk Apr 3, 2019, 9:31 PM

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ya. promotion happens from scalar to vector and i think demotion happens for vector to scalar ie

float x = float3(0, 1, 2);

results in x = 0

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i'll have to double-check that

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@atomic echo that is a great point

still carbon Apr 3, 2019, 9:32 PM

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yeah that'll result in 0

rotund tusk Apr 3, 2019, 9:33 PM

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try

float dis = distance( myGameObject.xyz, input.worldPos ); // assuming intput.worldPos is also float3

stark hornet Apr 3, 2019, 9:35 PM

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📎 c7b42786ca7593e8a09ab189d926a434.png

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this is what happens with distance() in the shader

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everything is at origin, nothing is parented, scaled, or rotated

still carbon Apr 3, 2019, 9:36 PM

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float dist = distance(_IntersectorsWorldPositions[0].xyz, input.worldPos);
clip(_Threshold - dist);
return col;```  if you just do it simple like that?

stark hornet Apr 3, 2019, 9:36 PM

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one sec, I'll test, but I believe it will give that same weird distance measurement

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yeah, exactly the same

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maybe it's the way I populate the float4 vectors on the C# script?

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intersectorsPositions[i] = intersectionsParent.transform.GetChild(i).transform.position;

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that's a float4 array

rotund tusk Apr 3, 2019, 9:38 PM

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try changing it to a float3[] in the shader

stark hornet Apr 3, 2019, 9:39 PM

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OH!

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it actually seems to be that

rotund tusk Apr 3, 2019, 9:40 PM

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smells like a bug with setting float4[] uniforms

still carbon Apr 3, 2019, 9:40 PM

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strange that would be the issue though, were you not using .xyz in the distance() like the last couple example showed?

stark hornet Apr 3, 2019, 9:40 PM

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so what could be happening with that float4 float3 difference?

still carbon Apr 3, 2019, 9:40 PM

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I mean in the distance() *

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sorry

rotund tusk Apr 3, 2019, 9:41 PM

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ok so you have it working with float3[] and distance?

stark hornet Apr 3, 2019, 9:41 PM

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yeah

rotund tusk Apr 3, 2019, 9:41 PM

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without the - 1 thing

stark hornet Apr 3, 2019, 9:41 PM

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yeah no -1 there

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gonna try also leaving it as float4 in the shader and feeding the last values of the float4 in the C# script as 0 and also as 1

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to see what happens

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yeah the result also changes

#

                                                   intersectionsParent.transform.GetChild(i).transform.position.y,
                                                   intersectionsParent.transform.GetChild(i).transform.position.z,
                                                   1);```

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that gives both same distance in world than in shader

rotund tusk Apr 3, 2019, 9:44 PM

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still very weird that the output would be different

stark hornet Apr 3, 2019, 9:44 PM

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with a 0 on that last line it gives weird different distances there

still carbon Apr 3, 2019, 9:45 PM

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well just to clarify as I didn't see an answer, you made sure to only use the .xyz in the distance() function right? cause if you were using distance on the full float4 I could see why that would happen

stark hornet Apr 3, 2019, 9:46 PM

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no I just passed the full float4 as it was

still carbon Apr 3, 2019, 9:46 PM

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yeah that's the issue

stark hornet Apr 3, 2019, 9:46 PM

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not the .xyz

rotund tusk Apr 3, 2019, 9:46 PM

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actually ya. that would give you different values

stark hornet Apr 3, 2019, 9:46 PM

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ohhhhhh

rotund tusk Apr 3, 2019, 9:46 PM

#

do the .xyz

stark hornet Apr 3, 2019, 9:46 PM

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one sec, testing, brb

rotund tusk Apr 3, 2019, 9:46 PM

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but the issue is because of the promotion of float3 to float4

atomic echo Apr 3, 2019, 9:47 PM

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glsl would compiler error IIRC

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but... microsoft lol

still carbon Apr 3, 2019, 9:47 PM

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float4 distance compare is a valid application tho

stark hornet Apr 3, 2019, 9:47 PM

#

yes indeed, .xyz = real distance / not .xyz = weird distance

still carbon Apr 3, 2019, 9:47 PM

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just not for this kind of distance

atomic echo Apr 3, 2019, 9:47 PM

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Yeah but make those conversions explicit lol

rotund tusk Apr 3, 2019, 9:47 PM

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promotion would be like this:

float3 x = float3( 1, 1, 1 );
float4 y = x; // y now = float4( x, 0 );

stark hornet Apr 3, 2019, 9:48 PM

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I can't believe I've wasted all your time like this with this stupid oversight

still carbon Apr 3, 2019, 9:49 PM

#

@atomic echo well the promotion in this case I believe is the Vector3 position from C# side being promoted to v4 and have a .w value that doesn't fall in line with vertex world pos. So how would that be enforced I guess

atomic echo Apr 3, 2019, 9:49 PM

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nah it's fine @stark hornet lol

stark hornet Apr 3, 2019, 9:49 PM

#

🙏🏽 I would kiss you all in the forehead If I was in the same room as you

atomic echo Apr 3, 2019, 9:49 PM

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@still carbon good point.

#

I'm imagining being bedtime kissed by Steve Buscimi.

stark hornet Apr 3, 2019, 9:50 PM

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so all has to do with the .w value of the float4 when taken from a raw vector3 position

#

right?

#

because giving the vector4 with position.xyz + 1 in the last place as the .w value worked fine

atomic echo Apr 3, 2019, 9:51 PM

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You could just split it out into a float3

still carbon Apr 3, 2019, 9:52 PM

#

yeah, the vector4 you'd get from the ObjectToWorld in the shader would have a w = 1 value, but the position you're feeding from C# side is only vector3, so fourth component defaults to 0

stark hornet Apr 3, 2019, 9:52 PM

#

I see

#

thanks a lot to everyone who helped me with this, not only I got a working solution with different ways of doing it, but also got now a better understanding about vectors in shaders and the HLSL distance function

#

really, thanks a bunch 😊 beginners like me would be fcked without peeps like you

still carbon Apr 3, 2019, 9:54 PM

#

@atomic echo Guess d3d11 errors too 😛

📎 68fdbdcf74a9f1eba28576eed33c1f74.png

stark hornet Apr 3, 2019, 9:59 PM

#

what would be more performant in theory? the HLSL distance() function or doing manually the sqrt of a dot?

#

I've read the HLSL functions are optimized and it's recommended to use them

#

instead of handcoding those kinds of things

#

can't find the full code of distance() from HLSL but found the one on CG Nvidia

#

{
  float3 v = vt2 - pt1;
  return sqrt(dot(v,v));
}```