Anisotropic reflections

anisotropy.hlsl

// 'coord.y' is the clip space y-coordinate of the pixel on the water.
// 'ray0.y/ray0.w' is the clip space y-coordinate of the reflected pixel.
// The basic idea is near the horizion where the reflected point is close to the water,
// you should have a strong reflection. The further it gets from the horizon the more it should be blurred vertically.
// The result is pretty good. :D

float aniso = _SSRAniso*abs(coord.y - ray0.y/ray0.w);
float2 ddy_uv = max(ddy(uv), float2(0, aniso));
...
float4 color = tex2Dgrad(_CameraColorTexture, uv, ddx(uv), ddy_uv);