Primary tessellation is a first pass through the geometry that creates a specific number of triangles in the U and V directions of the surface; it places triangles evenly all over the surface, regardless of curviness or displacement.
Secondary tessellation (also called Adaptive tessellation) is a second pass that creates more triangles only where needed.
With Maya software rendering and hardware, you can set basic and advanced tessellation settings.
Basic tessellation (for novice users) performs both primary and secondary tessellation, in the following ways:
- curvature tolerance affects the chord height ratio of the secondary attributes
- u/v divisions affects the number U/V, and uses per-span # of isoparms
If basic tessellation doesn’t provide you with the required results, choose advanced tessellation, and make adjustments accordingly.