float raySampleDepth = startDepth + rayDepth * sampleStep;
// Depth buffer depth for this sample
float sampleDepth = SAMPLE_TEXTURE2D_LOD(_CameraDepthTexture, s_point_clamp_sampler, sampleUV, 0.0).x;
bool Hit = false;
float depthDiff = sampleDepth - raySampleDepth;