These topics describe controls that are common to all or most Autodesk Materials.
Ambient Occlusion (AO) is a method spearheaded by the film industry for emulating the look of true global illumination by using shaders that calculate the extent to which an area is occluded, or prevented from receiving incoming light.
The controls for Round Corners soften the edges of objects without your having to alter geometry.
The performance-tuning parameters let you tune performance by limiting the amount of calculation an Autodesk Material has to perform.