URP id buffer

[wide mica]

You'd likely want to look into creating a custom renderer feature, to render these objects. I'm not sure there's much resources out there for it though. Might be a bit complicated, but I'll try to give some info/tips.

This might provide an example : https://gist.github.com/Cyanilux/d16dbfec869dbfb690426c837745679c
It doesn't use any IDs, basically just renders objects into a temporary buffer for masking a glitch effect I made. It's also a bit outdated, may want to look into switching RenderTargetHandle out for a newer RTHandle (which you'd generate using RenderingUtils.ReAllocateIfNeeded(ref temp, desc, name: "_TempTexture");, rather than the cmd.GetTemporaryRT).

I probably would store the ID in a property or vertex colours, rather than trying to use layers - as they aren't accessible in the shader. You could do a separate context.DrawRenderers for each layer but that's not very efficient.

The example code I have above uses overrideMaterial instead which would work if you store the ID in the Mesh.colors.
Otherwise can try changing it to overrideShader (new to 2022.2+ I think?) which works similar to the Replacement Shader for Built-in RP. That should allow properties to carry over from the shader it used before, so if both have an _ID property for example, that should allow you to set an id per material.

Would also want to change _TempGlitch to whatever global texture reference you want to sample in other shaders. And probably don't need the blit part either.

@velvet lintel (ping just to make sure you find/see this, not sure if creating a thread does that automatically)

[velvet lintel]

thanks, i will take a read of the code and see if i can understand it. These new pipelines are way more complicated than the old built in stuff 😦

[velvet lintel]

hmm maybe there is an easier way @wide mica is it possible to just have 2 depth textures but for specific layers rather than the whole scene

[wide mica]

Hmm maybe, but that would still require a custom renderer feature.

You'd use the same context.DrawRenderers call to draw objects on the layers specified by the layerMask (passed in the FilteringSettings stuct) and use the "DepthOnly" pass (in ShaderTagId list)

[velvet lintel]

do you think that is what they are doing here for this vfx:

because they some how know the frags are after a object of a certain height from the main camera but with respect to the npc's view

im thinking two depth textures because i can get the world position from that

some one said stencil but i can't see how stencil works from the main camera's pov

[wide mica]

The way I'd probably tackle something like this is a script calculating the appropriate field of view / line of sight meshes, similar to this : https://www.youtube.com/watch?v=rQG9aUWarwE (for green part, and an inverted version for the blue section you've circled)

It does look like the blue lined section is projecting onto the walls at the side though, so I'd probably say the line-of-sight meshes are more 3D and project onto objects similar to decals.

[velvet lintel]

i tried his method first but his method is using ray casts to change the mesh but that isn't very accurate without a lot of rays and is costly

my idea was depth texture from npc then clip where depth is before the npc's view mesh but with two depths i can change the alpha for waist height obstacles versus full on walls

[wide mica]

Sure depends exactly on the use-case. But there could be optimisations, like only recalculating if the units/surroundings move.

[velvet lintel]

yeah i know but shadow tactics use shaders as i have their source code they dont use the ray - mesh method like sebastian did

[wide mica]

You could also look into how shadowmapping for point lights work, that uses depth textures so might be a good reference.

[velvet lintel]

ive tried to find a good tutorial on shadow mapping but its all very low level since unity does it all for you that no one has covered the topic much =/

renderdoc shows them using stencil:

but i just don't see how that works for changing the alpha of the fragment

[wide mica]

With stencils you have a comparison function that discards fragments. That's why the line-of-sight effect isn't showing over certain objects (coloured white in this stencil buffer image)

That won't help with making it turn from green -> blue where an object is in the way though

[velvet lintel]

yeah but it also becomes fainter green after its behind the object unless its a full on wall in which case its occluded

how would they have done that 🤔

[wide mica]

I'm not sure, the only way I can think of is what I explained above with a script calculating line-of-sight meshes.