Getting Fog color and density

I have modified terrain shaders targeted at SM 3.0, which disabled the inbuild easy-to-use fog functionality.
So I need to obtain the values for fog color and density from Unity, so I can multiply them on the color output accordingly, but can't seem to figure out how to get the values. I'm still very new to the whole shader area, and the answer may be very simple...

To pass them by script is not an option, as I really haven't got any material (or MeshRenderer component) to pass it to, because it's a terrain shader.

?

 

Nobody seems to know anything about it, it seems.

The other day I came up with this method in my fragment program, after some research. This gives me precisely the same result as when using the inbuild fog. And yeah, I know this should probably go into the vertex program instead. Will change it when I have it right.

Code (csharp):

1.  
2.  
3. uniform float4 _AddFog;
4.  
5. float4 manualFogEXP2Fragment (v2f i) : COLOR {
6.  
7.      half4 whateverColorCalculated = blahblah;
8.  
9.      float whatEverDistanceFromView = someOtherBlahBlah;
10.  
11.      float fogDensity = 0.0015;
12.  
13.      float eFactor = 2.7183;
14.  
15.      float fog = 1/(pow(eFactor,(pow(fogDensity  * whatEverDistanceFromView,2)))); 
16.    
17. half4 c = lerp(whateverColorCalculated ,_AddFog,1-fog);
18.  
19.      // Another method than lerp(): half4 c = (1-fog) * _AddFog + fog * whateverColorCalculated ;  
20.    
21.      return c;
22.  
23. }
24.  
25.  

As you can see I still have the density of the fog as a hardcoded variable. I simply can't find a way of obtaining it automatically. At least I have the color from the uniform float4 value; _AddFog.

Still no real solution to the density? Am I being stupid?

 

That's so strange. Because they do. And they were obviously some of the first guesses of variable names I tried. Have no idea what I did wrong elsewhere, when I first tried out these. I just know they didn't work then.
Stupid.

Thx Aras

 

Hi,
I was searching for exactly this (despite being a very old thread), but I cannot make it work. Using "float4 _FogColor;" always returns black, despite being configured properly in the RenderSettings. For additional info I'm trying to access this on the vertex shader. Any clues?

 

Just in case anybody finds this, it's "unity_FogColor"

 

Thanks gametr4x, declaring "float4 unity_FogColor" worked for me!

 

just in case anybody fell here, is not necessary more declares

https://forum.unity.com/threads/unity_fogcolor-not-working-in-unity-5.313002/

 

Thanks @mauriciofelippe , this worked for me

Code (CSharp):

1. changed this->  UNITY_APPLY_FOG_COLOR(IN.fogCoord, result, fixed4(0, 0, 0, 0));
2.  
3. for this ->  UNITY_APPLY_FOG_COLOR(IN.fogCoord, result, unity_FogColor);