Shadow and distance attenuation do not work in URP Unlit Graph

So a related issue for me was that additional light shadow has no attenuation. This was solved for me by looking at the lighting.hlsl which contains two forms of GetAdditionalLight(), one of which accepts a shadow mask and the other does not. Without suppling the shadowmask (i.e. half4(1,1,1,1)) the shadowAttenuation is otherwise 1

 

Anyone resolved this issue in URP 11.0?
After trying all of the above I still can't recieve shadows in my unlit graph...

 

I just give up and have been using lit instead.

 

Hi, Actually yesterday I found a blog that gave me a tip.

Code (CSharp):

1.     // --- RUDIMENTARY SHADOWs   Keywords: _MAIN_LIGHT_SHADOWS_CASCADE && _SHADOWS_SOFT --- \\  
2.     float4 shadowCoord = TransformWorldToShadowCoord(WPos);      
3.     float shadowAtten = SampleShadowmap(shadowCoord, TEXTURE2D_ARGS(_MainLightShadowmapTexture, sampler_MainLightShadowmapTexture),
4.     GetMainLightShadowSamplingData(), GetMainLightShadowStrength(), false);

Use this code before the main light function call and multiply the lighting by 'shadowAtten', and don't forget to defing the keywords in the graph.

This is the final custom function:

Code (CSharp):

1. #ifndef CUSTOM_LIGHTING_INCLUDED
2. #define CUSTOM_LIGHTING_INCLUDED
3.  
4. /* IN(5): SpecColor(4), Smoothness(1), WPos(3), WNormal(3), WView(3) */
5. /* OUT(2): Diffuse(3), Specular(3) NdotL(1) for toon ramp: point,clamp) */
6.  
7. void CalculateLights_half(half4 SpecColor, half Smoothness, half3 WPos, half3 WNormal, half3 WView,
8.                           out half3 Diffuse, out half3 Specular)
9. {          
10.     Diffuse = 0;
11.     Specular = 0;
12.     #ifndef SHADERGRAPH_PREVIEW
13.  
14.     Smoothness = exp2(10 * Smoothness + 1);  // WNormal = normalize(WNormal);    WView = SafeNormalize(WView);
15.    
16.     // --- RUDIMENTARY SHADOWs   Keywords: _MAIN_LIGHT_SHADOWS_CASCADE && _SHADOWS_SOFT --- \\  
17.     float4 shadowCoord = TransformWorldToShadowCoord(WPos);
18.     float shadowAtten = SampleShadowmap(shadowCoord, TEXTURE2D_ARGS(_MainLightShadowmapTexture, sampler_MainLightShadowmapTexture),
19.     GetMainLightShadowSamplingData(), GetMainLightShadowStrength(), false);
20.    
21.     Light light = GetMainLight(shadowCoord); // Main Pixel Light
22.     half3 attenCol = light.color * light.distanceAttenuation * shadowAtten;
23.  
24.     Diffuse = LightingLambert(attenCol, light.direction, WNormal);     /* LAMBERT */        
25.     Specular = LightingSpecular(attenCol, light.direction, WNormal, WView, SpecColor, Smoothness); /*Blinn-Phong*/    
26.  
27.     #endif
28. }
29. #endif

The shadows and pitch black and not attenuated, maybe I'm still missing something, but it's a start.

 

After doing a bit of research I've found two solutions. In both cases they work with the function MainLight_half shown here without modifications (You only need to change #if SHADERGRAPH_PREVIEW into #if defined(SHADERGRAPH_PREVIEW)):
https://blogs.unity3d.com/2019/07/31/custom-lighting-in-shader-graph-expanding-your-graphs-in-2019/

-> Solution 1: Use the Lit graph
1) As suggested before, just plug your custom lighting into the "Emission" node, setting to 0
everything else.
2) Add _MAIN_LIGHT_SHADOWS and _MAIN_LIGHT_SHADOWS_CASCADE keywords in Shader Graph and set them to multi compile & global.


-> Solution 2: Use the Unlit graph
1) Make sure in your URP shadow settings the cascade count is set to 2 or above.
2) Add _MAIN_LIGHT_SHADOWS and _MAIN_LIGHT_SHADOWS_CASCADE keywords in Shader Graph and set them to multi compile & global.

The unlit shader will only work with cascade shadows.
If you want to support non-cascade shadows, then you'll have to make changes to the generated shader as Unity looks for a new Varying called "shadowCoord" which the unlit graph doesn't generate. (In this case, you're probably better off using the Lit graph instead)

 

"Solution 1: Use the Lit graph"
This seems the easier way. That said i found this and they are using Unlit. I'm yet to download it to check

 

Interesting, thanks for sharing! I took a look at their project and found out what's going on:
As I wrote above, the unlit graph can't handle non-cascade shadows as it lacks the "shadowCoord" varying, so I suggested adding the two defines to force the shader to use cascade shadows. (The NG combination of keywords is when _MAIN_LIGHT_SHADOWS is defined but _MAIN_LIGHT_SHADOWS_CASCADE is not. That's when Unity will look for shadowCoord)

When using a multi_compile keyword I believed Unity would compile all shader combinations, including the error one, but that appears not to be the case. It's only compiling them as necessary.
Since the above project is using cascade shadows, everything works fine. If you try to set the cascade count to 1 in their URP asset, Boom, the scene turns pink and all their graphs don't work anymore

I updated my solution 2 above to this simpler one

 

2021.1 This is also not working
The TransformWorldToShadowCoord seems to not work at all so I tried the
half cascadeIndex = ComputeCascadeIndex(WorldPos);
half4 shadowCoord = mul(_MainLightWorldToShadow[cascadeIndex], float4(WorldPos, 1.0));
But also no shadows from other objects. This is really annoying...

 

Thanks for sharing this because of this I was able to solve the issue in the newest unity version:
Using their script:
https://github.com/UnityTechnologie...Assets/Shaders/CustomHLSL/CustomLighting.hlsl

And these settings:

 

I'm using the unity 2020.2.6f1 version, and the URP version 10.3.1.
I dont know about shader code so, i watched this tutorial in you tube:

, and i did all the stuffs he did.

The problem happends when i do the cast shadows (according to the tutorial) and didn't work for me. The material works, but cast shadows doesn't.
After this, i change the MainLight_half function (that you guys posted), and does not work.
and i tryed include the:
#pragma multi_compile _ _MAIN_LIGHT_SHADOW
#pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE
and and does not work too.
can you help me guys ?

 

Try the settings I posted on my screenshot.

 

The link to this image expired, do you perchance still have this screenshot somewhere?

 

https://chulin28ho.tistory.com/690
in 2021.2.3 , it worked.

 

I have a custom URP Opaque shader that received shadows fine in Unity 2019 and now does not in Unity 2021.3, is there something changed in the shader libs for that case ?

EDIT:

I found the cause, in the below code seems defaults to the second line than the first, seems _MAIN_LIGHT_SHADOWS fails to register or something, even though i have it in multi compile etc

Code (csharp):

1.  
2. #if _MAIN_LIGHT_SHADOWS
3.                 mainLight = GetMainLight(TransformWorldToShadowCoord(positionWS));
4. #else
5.                 mainLight = GetMainLight();
6. #endif
7.  

Is there something i am missing ? If i use the below code works

Code (csharp):

1.  
2. #if _MAIN_LIGHT_SHADOWS
3.                 mainLight = GetMainLight(TransformWorldToShadowCoord(positionWS));
4. #else
5.                 mainLight = GetMainLight(TransformWorldToShadowCoord(positionWS));
6. #endif
7.