Help Wanted Using the Fog node with a unlit master

Using the fog node with a unlit master node being active result in the return value of the density being completely black (understand 0). When a PBR master node is active however the density value is correct. This is happening on URP 7.1.7/unity 2019.3 and URP 7.1.8/unity 2020. Has anyone encountered this problem and how can it be solved?

 

Hello, I'm currently trying to add fog to a shader and have the exact same issue.
Did you already reported it as a bug ?

 

Thank you very much !

 

Hey I finally got around to fixing this issue. I ended up implementing a exponential squared fog since this is what we would be using but the other formulas are as follows and people can implement them easily.

Code (CSharp):

1. Linear Fog = (FogEnd - ViewpointDistance) / (FogEnd - FogStart)
2. Exponential Fog = 1.0 / 2.71828 power (ViewpointDistance * FogDensity)
3. Exponential Fog 2 = 1.0 / 2.71828 power ((ViewpointDistance * FogDensity) * (ViewpointDistance * FogDensity))

I'm also uploading the relevant nodes in the shader graph.

 

Code from the URP Core.hlsl

Code (CSharp):

1. real ComputeFogIntensity(real fogFactor)
2. {
3.     real fogIntensity = 0.0h;
4. #if defined(FOG_LINEAR) || defined(FOG_EXP) || defined(FOG_EXP2)
5. #if defined(FOG_EXP)
6.     // factor = exp(-density*z)
7.     // fogFactor = density*z compute at vertex
8.     fogIntensity = saturate(exp2(-fogFactor));
9. #elif defined(FOG_EXP2)
10.     // factor = exp(-(density*z)^2)
11.     // fogFactor = density*z compute at vertex
12.     fogIntensity = saturate(exp2(-fogFactor * fogFactor));
13. #elif defined(FOG_LINEAR)
14.     fogIntensity = fogFactor;
15. #endif
16. #endif
17.     return fogIntensity;
18. }