Soft shadows for point lights (my implementation)

I made the realization of soft shadows for point lights. In order to make it work , you need to find in folder "...\Unity5\Editor\Data\CGIncludes" file "UnityShadowLibrary.cginc" and edit it.

To see the result , you need to find a folder of your project . In it find the folder "Library". Remove from this folder directory "ShaderCache" and restart Unity. Yes, I restarted Unity after each compilation.

See in "UnityShadowLibrary.cginc". We need this cut:

Code (csharp):

1.  
2.     #if defined (SHADOWS_SOFT)
3.  
4.         float z = 1.0/128.0;
5.         float4 shadowVals;
6.         shadowVals.x = SampleCubeDistance (vec+float3( z, z, z));
7.         shadowVals.y = SampleCubeDistance (vec+float3(-z,-z, z));
8.         shadowVals.z = SampleCubeDistance (vec+float3(-z, z,-z));
9.         shadowVals.w = SampleCubeDistance (vec+float3( z,-z,-z));
10.         half4 shadows = (shadowVals < mydist.xxxx) ? _LightShadowData.rrrr : 1.0f;
11.  
12.         return dot(shadows,0.25);
13.  
14.     #else
15.  
16.  

What do we see ? Artfully created a small offset vector. Works quickly, looks terrible:



First of course you need to choose the offset is not in all three dimensions, but in a plane perpendicular to the vector from light. Thus, we will work with the cubemap as a flat texture. So you need to be less than the sample for best results.
To obtain the virtual vector we start axes X and Y, then store them in different sequences , thereby selecting a point on the same virtual plane. No matrix , everything fast and simple.
And second - we need some random. It was effect like Disk Bloor.

Code (csharp):

1.  
2.   #if defined (SHADOWS_SOFT)
3.  
4.         // Smaller number is more blur
5.         float downscale = 32.0f;
6.  
7.         // Random vector
8.         const float3 rndseed = float3(12.9898,78.233,45.5432);
9.         float3 randomvec = float3( dot(vec,rndseed) , dot(vec.yzx,rndseed) , dot(vec.zxy,rndseed) );
10.         randomvec = frac(sin(randomvec) * 43758.5453);
11.  
12.         // Vectors of X and Y axis for virtual planar
13.         float3 xvec = normalize(cross(vec,randomvec));
14.         float3 yvec = normalize(cross(vec,xvec));
15.  
16.  
17.         // Two offsets
18.         float3 vec1 = xvec / downscale;
19.         float3 vec2 = yvec / downscale;
20.  
21.         float4 shadowVals;
22.  
23.         // Four samples
24.         shadowVals.x = SampleCubeDistance (vec+vec1);
25.         shadowVals.y = SampleCubeDistance (vec+vec2);
26.         shadowVals.z = SampleCubeDistance (vec-vec1);
27.         shadowVals.w = SampleCubeDistance (vec-vec2);
28.  
29.         half4 shadows = (shadowVals < mydist.xxxx) ? _LightShadowData.rrrr : 1.0f;
30.         return dot(shadows,0.25);
31.  
32.     #else
33.  
34.  

And see:



Here there are the same four samples , but the difference is enormous. Pixels are no longer visible. With good textures dithering was invisible. You can see what now there's not a bias problem.

And now - warning! We can make Area Light like effect:

Code (csharp):

1.  
2.    #if defined (SHADOWS_SOFT)
3.  
4.         #define SHADOWS_SOFT_AREALIGHT
5.  
6.         float downscale = 32.0f;
7.         float areascalefactor  = 10.0f;
8.  
9.         const float3 rndseed = float3(12.9898,78.233,45.5432);
10.         float3 randomvec = float3( dot(vec,rndseed) , dot(vec.yzx,rndseed) , dot(vec.zxy,rndseed) );
11.         randomvec = frac(sin(randomvec) * 43758.5453);
12.  
13.         float3 xvec = normalize(cross(vec,randomvec));
14.         float3 yvec = normalize(cross(vec,xvec));
15.  
16.         float3 vec1 = xvec / downscale;
17.         float3 vec2 = yvec / downscale;
18.  
19.         float4 shadowVals;
20.  
21.         #if defined (SHADOWS_SOFT_AREALIGHT)
22.  
23.             // Lookup
24.             shadowVals.x = SampleCubeDistance (vec+vec1);
25.             shadowVals.y = SampleCubeDistance (vec+vec2);
26.             shadowVals.z = SampleCubeDistance (vec-vec1);
27.             shadowVals.w = SampleCubeDistance (vec-vec2);
28.  
29.             // Choose distances sum
30.             float shadowdist = mydist - dot(shadowVals, 0.25f);
31.  
32.             // Change bloor factor
33.             downscale *= 2.0f / (1.0 + (shadowdist > 0.0f) ? (shadowdist * areascalefactor ) : 0.0f);
34.            
35.             vec1 = xvec / downscale;
36.             vec2 = yvec / downscale;
37.  
38.         #endif
39.  
40.         // Continue old operations
41.         shadowVals.x = SampleCubeDistance (vec+vec1);
42.         shadowVals.y = SampleCubeDistance (vec+vec2);
43.         shadowVals.z = SampleCubeDistance (vec-vec1);
44.         shadowVals.w = SampleCubeDistance (vec-vec2);
45.  
46.         half4 shadows = (shadowVals < mydist.xxxx) ? _LightShadowData.rrrr : 1.0f;
47.         return dot(shadows,0.25);
48.  
49.     #else
50.  
51.  

If you know russian language you can find more information in this thread:
GameDev.ru

 

Where is that value mydist came from?
Edit : My Bad, haven't check the real code before. ignore my question