I have found out how to Burn a badass hole in my Fog of war texture:
Code
float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
float dx = coords.x - 0.0f;
float dy = coords.y - 0.0f;
if (dx * dx + dy * dy <= 0.02f){
float4 color = float4(1.0f, 0.0f, 0.0f, 0.0f);
return color;
}
else{
float4 color = float4(0.0f, 0.0f, 0.0f, 0.5f);
return color;
}
}
Now I need to find out how I can pass the Shader at which positions he shall do this.
and how I calculate 3D Worldpositions to texturecoordinates