Clarisse provides several tessellation modes to drive tessellation schemes and thus level of detail of displacement. These attributes are defined in geometries.
Mode |
Description |
Adaptive (base) |
This special heuristic performs adaptive tessellation based on primitive areas of the base geometry (without deformation). The level of tessellation is defined by Displacement Adaptive Span Count attribute. |
Adaptive (deformed) |
This special heuristic performs adaptive tessellation based on primitive areas of the deformed geometries. The level of tessellation is defined by Displacement Adaptive Span Count attribute. |
Uniform |
Perform uniform non-adpative tessellation. Each quad of the displacement mesh is subdivided by Displacement Uniform Span Count . For example a level of 2 subdivides a quad into 4 new quads. |
When using adaptive modes, the level of tessellation is defined by Displacement Adaptive Span Count. This value is relative to the max extent of the bounding box of the geometry that is displaced. The best way to understand how this heuristic works is to imagine you are subdividing the bounding box of the underlying geometry instead. In fact when you set a value of 200 spans, this defines the size of the micropolygon according to the bounding box size. The geometry is subdivided adaptively using this micropolygon size. The mode doesn't add micropolygon to primitives which area is smaller than the micropolygon size. The resulting tessellation tends to become uniform.
Displacement Adaptive Span Count set to 5 on an implicit sphere
Displacement Adaptive Span Count set to 20
Displacement Adaptive Span Count set to 200
No tessellation
Uniform tessellation (4). Note the heterogeneous tessellation.
Adaptive tessellation (500). Note the homogeneous tessellation.
