Hi, I have included a hip file with a few examples of shader based ambient occlusion, each of them slightly different and I was wondering if anyone could tell me what is going on in them...? Example 1: Nothing plugged into AO position or surface normal inputs. So it should use the global variables by the same names. Fine... But what space are the surface position and surface normals in in this case? Camera space? Object space? World space? Example 2: Same as example 1 except that the AO po