Toon Cel-Shaded version of URP/Terrain/Lit?

[unique thicket]

Would it be possible to take the stock unity Shader "Universal Render Pipeline/Terrain/Lit" and re-write the light calculations to be stepped/toon/cel-shaded style?

The doccument is very large and I am not experienced with writing shader code, only using shadergraph.

Where exactly in "URP/Terrain/Lit" is the "light" pass that refers to actual lighting? Where would I edit it to change how lighting is done?

[brittle ridge]

Should be possible. Assuming Forward/Forward+ rendering paths, shading is handled by the UniversalFragmentPBR function call in TerrainLitPasses.hlsl

So something like

• Copy the terrain shaders & TerrainLitPasses.hlsl under the Shaders/Terrain folder.
• In the copied shaders, update the path to that TerrainLitPasses include
• In the copied hlsl file, replace UniversalFragmentPBR with your own toon-shading function

[unique thicket]

Forgive me I am a little slow.
I see reference to that file you mention as #includes. How do I find and open that file however?
Once I find it, you are saying I should make a copy, and rewrite inside of it the light/shadow calculations, and then divert the references:
#include "Packages/com.unity.render-pipelines.universal/Shaders/Terrain/TerrainLitPasses.hlsl"
to my rewritten version?

I was able to find the terrain lit through here, but I don't know how to dig deeper and find TerrainLitPasses.hlsl

oh I found it

TerrainLitPasses is very bloated, its hard to see when/where im supposed to edit what to get toon ramp cel shaded lighting

trying hard to step by step what you've suggested copy them first step, redirect next step, update last step

Redirected to the copied version

So far so good, it accepts the new material, and the base original Terrain seems to be working

now I just have to find the lines in the LitPasses and rewrite them with a basic toon implementation

half4 color = UniversalFragmentPBR(inputData, albedo, metallic, /* specular */ half3(0.0h, 0.0h, 0.0h), smoothness, occlusion, /* emission */ half3(0, 0, 0), alpha);

like you said, I should replace that line with my own function

Is there any way to see what UniversalFragmentPBR method looks like?

for toon shading I dont need most of that stuff, but like I don't even know what variable data type a "inputData" is

I get an underclaired identifier with just this

[brittle ridge]

It's in URPs ShaderLibrary/Lighting.hlsl (also a BlinnPhong version of that function which is simpler than PBR)

[unique thicket]

that will help fix the arguments being passed in

[brittle ridge]

I think InputData is in Input.hlsl iirc. But functions in TerrainLitPasses should initalise that struct

Or maybe in TerrainLitInput.hlsl, not sure off top of my head

[unique thicket]

Okay I found it, looks like UniversalFragmentPBR is quite large, no surprise there, this gets me the right inputs however

okay the inputs passed in are right

hm why is there an undeclared identifier

it says the method name itself is undeclared

but I declared it right there

maybe i need to move it inside the bracket

Nope that didnt work

[brittle ridge]

Might need to be before the fragment function

[unique thicket]

Oh order in the file might matter?

It does appear to matter, moving it up fixed it

[brittle ridge]

Yeah I think in hlsl functions need to be defined before they are called

[unique thicket]

hmrgh I hit a snag that I don't think is surmountable

A lot of their code is hard coded to deal with exactly 4 textures

But weirdly the default terrain material does allow for and works with more than 4 textures

except in my version, its applying black to the first four textures

and I need it to affect all of the textures, not just four

those other textures must still be using the default terrain material Im guessing? but where/how do I find that to resassign it

I was only able to reassign the terrain material through the Debug inspector

it seems like the terrain material that I reassigned is just one of many

and that unity Terrain uses a bunch more in different contexts and zoom levels

[brittle ridge]

Ah yeah terrain shaders are actually multiple shaders (in BiRP and URP at least). In the Shaders/Terrain you'll also find TerrainLitAdd (which handles another 4 paintable layers etc). Also TerrainLitBase and TerrainLitBasemapGen, though I'm not entirely sure what those ones do tbh

[unique thicket]

the black I expect, thats my code returning all 0's

[brittle ridge]

Those shaders get connected to the main shader using a "Dependency" - I think defined at the bottom of TerrainLit.shader

[unique thicket]

I see, Ill copy those over and update their Lit path includes as well

oh these files are not the same files

I dont think I have access to the Hidden folder

these files exist, but its a different path and different filename

Base and Add don't appear to be referenced anywhere else but the Dependency at the bottom

How do I redirect this Hidden path reference to my version, will it be enough to just give it the path to that new file? Even though the filenames dont match?

Oh when I open it, that's its name, not file path

I see now

okay making progress redirecting the dependencies

Hm okay, I redirected all the dependencies, but nothing has changed on the material in the scene

which is odd, I expect that all if it should be showing black now

oh

it wasnt using the right material

now its all black, thats good

hmm lots of errors

some progress

I have it returning its unshaded albedo

but if you zoom out too far, one of the terrain shader/materials is fuxed

ill grab Input which it can't seem to find maybe and make a toon version of that too?

DetailLit maybe is the missing one?

I don't have any grass and I cloned the other ones

but I didnt see any reference to detail lit so far

[brittle ridge]

Probably yeah. It looks like the path in the BasemapGen one is a relative path rather than the Packages/... one so it's looking in the same folder as your shader

[unique thicket]

Ahh

ill update all the include paths on all of them to a clone

[brittle ridge]

And in the Add shader you might have changed paths for both includes when you only copied one file

[unique thicket]

Hm when I updated TerrainLitAdd to the copied file, the whole Terrain turned pink

It's not that big of a shader file

[brittle ridge]

Does the console have errors? Or inspector when shader is selected

[unique thicket]

Let me try reloading the scene or saving or something, I don't see any errors but maybe I cleared them

when I reassigned the material, it turned back from completely pink to only pink in the distance again, weird

Ill keep going making sure all the Input files are redirected

Fixed all the console errors and paths, but it sstill pink in the distance

this is the only console message currently

[brittle ridge]

I think pink in distance means an error in the BasemapGen or Basemap shaders.
Not totally sure but I think the Gen one is used to bake out the albedo into a texture, which is passed to Basemap to render distant terrain.
But that baked texture is probably lower res, so TerrainLit shader is used for close-up terrain.

It could be that you need to reload the scene or something to force it to regenerate that baked texture?

[unique thicket]

Oh, yeah, hitting File > Save instantly unpinked it

whew okay good progress, we have the full Terrain material path shader redirected, from here I just have to convert my shadergraph code for toon ramp to HLSL/CG/normal text code, which I think I can do

I think I will give it a break here and start again fresh on that next time because I've been at this all day and my brain is mush, thank you for the help as always Cyan 🙌

[unique thicket]

Working on this again, I have this basic setup, but I hit a wall

I don't have the surface normals passed in

and I dont know where to get them, or how to get them

the original universalPBR didnt pass in normals either oddly

so im a little unclear how they calculated light/shadow without the normals

oh maybe its in the inputdata

woo that's a start

gotta tweak the actual math, probably want to use smoothstep not step, and include two bands

[unique thicket]

I've kep't working on this and I've hit a new problem

I re-wrote the blending logic so that it uses a dither pattern instead of just a soft linear alpha blend

it works, for the first four materials

but then all subsequent materials, it doesn't

the part thats stumped me is all the different passes derive their logic from ToonTerrainLitPasses

which is where I rewrote the blending logic

each shader derivative doesn't have its own blend logic, they all reference that one file

so I dont understand why rewriting it in one place didn't rewrite it for all of them

im 100% positive they've all been rewritten to target my code, not anything still making use of stock original Terrain code

[brittle ridge]

Maybe something to do with the main pass only blending/dithering between colours while additive passes have transparency?

Though I guess there's red/green touching above and if those are drawn by the same additive pass I'd expect those to dither

[unique thicket]

ive been trying to fix this for days now

I got every material dither blending on texture layers 1-4

and every material dither blending on texture layers 5+ which are added from the Add pass

but I CANNOT get the add pass layers to dither blend with the original 1-4 layers

and I keep rewriting it and trying debug after debug and im looking and looking and I cannot find anything wrong I cannot find a reason why its doing this, im going insane

its dither blending sorta

but its ALSO not dither blending

and I dont have a @#$@^@ clue why or how its even possible that it can be doing both

I cant move forward on anything until I fix it

but I cant fix it no matter how hard I try

im so stuck

I dont know what more to do than to show others

ive tried and tried and tried

the entire fragment and color mixing methods have been rewritten to use a ton of submethods trying to make it easier to work with

unity's code is such a mess though

they tried to cram like 5 separate pipelines of shader code into this one thing and it makes it impossible to get anything done or change anything

i just want it to not use soft alpha falloff

but i can barely make heads of tails of their code to find every instance of where its happening in order to remove it

fffffffffffffffffffffffffffffffffffffinally

I just resorted to directly overwriting the alpha at the last step of the render pipeline with the dither alpha

of course ive only fixed Lit and LitAdd

LitBase and LitBasemapGen still use wrong code

as soon as you zoom out, it blurs again because the 'low spec' versions of the terrain shader are untouched and I have to re-write the same stupid edits over and over for every one of their dumb cascade of subsitution shaders

except im just NOT going to do that and leave it broken because im using an orthographic camera and Its depth means it never uses the 'low spec' shader