int y = id.x / int(_ScreenWidth);
int x = id.x % int(_ScreenWidth);
// the depth-information. We get _DepthTexture from a pixelshader.
float4 depthInfo = _DepthTexture[uint2(x, y)];
float depthValue = depthInfo.z * _CamFar;
// world X and Y components of our target vector
float tanFov = tan(radians(_CamFOV / 2));
float screenDimY = tanFov * _CamNear;
float screenDimX = screenDimY * _CamAspect;
// normalize screenpos from range 0..1 to range -1..1
float4 normPos = depthInfo * 2 - 1;
float screenPosX = screenDimX * normPos.x;
float screenPosY = screenDimY * normPos.y;
float screenPosZ = -_CamNear;
float4 objInEyeSpaceVector;
objInEyeSpaceVector.xyz = float3(screenPosX, screenPosY, screenPosZ) * depthValue / _CamNear;
objInEyeSpaceVector.w = 1;
float4x4 camWorldMat = float4x4(_CamWorldMatrix0, _CamWorldMatrix1, _CamWorldMatrix2, _CamWorldMatrix3);
float4 pixelPosition =  mul(camWorldMat, objInEyeSpaceVector);