#While I can just bake the tree s colors

1 messages · Page 1 of 1 (latest)

sharp wasp
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How many different color ramps do you need

small elk
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It will vary based on the object in question.

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For the tree, since it has Green and Brown

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I would need two ramps if I wanted it to have a single material

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likewise, for something like a house

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it might need more ramps to compensate for the multiple colors that go into that

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Hence my questions about instanced materials, and whether or not they're worth considering as an option

sharp wasp
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I don't understand if ramp is the texture, a ramp is sampled for a (solid color) texture, or if a texture is sampled for a ramp

small elk
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if Instanced Materials aren't as performantly heavy as regular materials, I might consider just using those, somehow.

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The object's lighting is converted into greyscale, and then used as an alpha to blend between two colors, or so I assumed. Are we thinking of different definitions of a color ramp?

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So I need to be able to define at least two colors, light and dark, and have the object lighting be used to create a gradient between those two on the object in question

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I could try making you an example in blender if this isn't making sense to you.

sharp wasp
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That might help

small elk
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One moment

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I'll whip up a quick example.

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@sharp wasp As you can see here, this tree has two materials, in blender. One for the leaves, and one for the wood. Each having a unique pair of two colors in its color ramp

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I can't think of a way to replicate this in Unity without actually HAVING multiple materials

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which isn't performant

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Which is why I was asking about Instanced Materials, which I don't quite understand in terms of how they contribute to draw calls, and how efficient/inefficient they are

sharp wasp
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Will the lighting be baked or does it react to lighting changes on unity side?

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Sorry for so many questions xD

small elk
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It will need to react to lighting changes, yes

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this methodology, if I can get it working at all

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will be applied to everything in my scene, in some form or another

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this is because my game using a color grading system which chooses "weird colors" from time to time

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and a simple color ramp corrects for this autonomously.

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Here's an example I showed to some other people

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The default scale of lighting from dark to light on a white object results in "weird colors" being chosen by my palette forcing setup, as a consequence of distance comparisons in color space

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But by using a color ramp to map light values to a color range and ignoring color data

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I can correct for this

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using a theoretical "red object being lit or darkened"

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compared to one who has had its color value stripped, and its lighting data fed directly into a color ramp of my own choosing

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While I could use a hackneyed solution involving blueshifting towards darker colors and apply it to all materials and colors universally to MAYBE get a similar result

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it would still result in "weird color" issues with my grading method, which is easily solved in blender at least through the use of color ramps

sharp wasp
small elk
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It's a full screen post process. It's expensive, but it ensures that literally everything in the game, no matter what I do or what lighting it is in, will comply with my palette.

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I have some examples if oyu want to see them

sharp wasp
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The challenge with that I suppose is that it won't know when to use a different shadow color per surface

small elk
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Yes

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which is why I'm asking about the best way to handle using multiple color ramps on a single object

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And whether or not Instanced Materials are meaningfully useful in something like this

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essencially

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if this helps explain my goal at all

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I want to be able to assign parts of a model specific colors (that have associated color ramps that are fed their lighting values)

sharp wasp
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Aren't material instances just at runtime duplicates of existing materials?

small elk
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To my knowledge, yes.

sharp wasp
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Which is like, the exact opposite of optimized

small elk
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Ok, so those aren't a solution, then.

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which is a question I had.

sharp wasp
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Assuming there has to be a custom light ramp per object in addition to the grading PP, the crude approach would be to use separate materials for each part with a property for shadow color and light color

small elk
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Which is what I want to avoid, since using seperate materials for each part, or so I've heard, is basically the worst possible thing to do.

sharp wasp
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Doable, but won't work with GPU instancing or SRP batching

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So the question comes down to how can we store two different colors per surface with the exact same material for everything

small elk
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It's strange to think I can't just use one material for everything and change its colors for each part.

sharp wasp
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Well you can if the colors are stored in a texture

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"Palette mapping" it's sometimes called

small elk
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I did consider the solution of just baking two textures, one for lights, and one for darks

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Then the material could simply be fed both colors as texture maps

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and plug them into the ramp

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but that's a fairly excessive amount of work and allows for zero tweaking in unity

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all editing I did would have to be in Blender itself,

sharp wasp
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If every object samples the same palette, it'll be perfectly compatible with GPU instancing

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Since we need a shadow color as well, my idea is to either use vertex colors for that, or sample the same palette texture plus/minus one grid cell's length

small elk
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Interesting. I'd have to set up a special texture that has color ramps built in, exactly.

sharp wasp
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So the shadow color would always be grabbed from an adjacent tile on the palette

small elk
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So the tree's UVs would all be on the "light green" cell

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while the Light and Darks would be sampled from surrounding cells

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That's intriguing.

sharp wasp
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Yes

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Both ideas are kind of clumsy if you need to change stuff afterwards but I guess they'd work

small elk
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definitely clumsy.

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I MIGHT experiment with it, but at this point, it's looking more like I'll just be having to put up with "Weird Colors" in my fullscreen shader.

sharp wasp
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And the adjacent cell method only works if you can trust that the palette cells are at a defined distance

small elk
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Yeah, I'd have to make the palette texture myself

sharp wasp
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But that distance could be defined as a global float

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So you can change it easily if you need to change the cell grid size

small elk
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Another possible problem is that this would be completely incompatible with certain other things

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since the UVs would be turned into glorified color pickers

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I couldn't effectively use the UVs for normalmaps or anything other than those palette setups

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due to them being much smaller

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Or the palette would need to be inordinately large

sharp wasp
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True, not ordinarily

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There can be multiple UV channels though

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For example unity uses the second channel for baked lightmapping

small elk
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Yeah, but I also have to take into account the unspoken resource of personal time required

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If every material and object I make requires TOO many hoops to jump through to set up a very simple visual effect

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Time might be better spent elsewhere.

sharp wasp
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If you've got the color picker thing operational it shouldn't be much effort to make new assets

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The palette texturing method is probably the quickest one out there anyway

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Oh and triplanar mapping is also an option if you want to add detail or normal textures on top of everything

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Usually something you end up using for environments anyway and doesn't take any extra effort to use once you've got it

small elk
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I'll probably just ditch the idea of using color ramps and bake my asset textures. I don't really understand how Triplanar mapping works, from what little I've seen from a quick google search.

sharp wasp
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Almost like a bit of a cheat since you don't even need UVs

small elk
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I can see some uses for it, definitely. I'll look into it if setting it up doesn't turn out to be too much of a chore at this stage of development.

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then again

sharp wasp
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Which render pipeline are you working in?

small elk
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HDRP.

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I don't know any better, so I just picked that one.

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and at this point

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I'm unsure if I could even change to URP without breaking my project irrecoverably

sharp wasp
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Unlikely

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HDRP offers triplanar node by default in shader graph

small elk
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Oh

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Well, that's handy!

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lmao, guess I was worried for nothing, in that case.

sharp wasp
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I hope you haven't been writing HDRP shaders by hand 😂

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HDRP also uses SRP batching which usually performs better than GPU instancing, and they are mutually exclusive

small elk
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Well, I did set up a sobel outliner using a several year old tutorial and wrote my own colorspace distance grading tool after getting frustrated with LUTs.

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I don't suppose you know a way to convert a LUT into a true Point-interpolated 3D texture, instead of the gradiated ones that Unity generates against your will?

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I tried using a LUT for my palette forcer, but it blended the colors together in a really nasty way because of how unity interpolated between the layers, and I couldn't figure out a way to make it not do that.

sharp wasp
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There are 3D texture / texture array formats which may interpolate better in that use, but I don't really know

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I never worked with LUTs

small elk
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Any good ways to force a strict palette other than brute forcing it with color space distance comparisons?

sharp wasp
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Besides sampling gradients I don't know any other ways

small elk
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sampling gradients?

sharp wasp
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You know... color ramps?

sharp wasp
small elk
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Ahh, yeah.

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Sorry, I've got brainrot from only ever using blender up until like a week ago and on and off a few years before that.