Pinned curves are a special case of non-periodic cubic curves (relevant only for BSpline and CatmullRom basis) where the authored intent is for each curve to begin and end at its first and last control points respectively. This is done by setting the 'wrap' mode on the topology to 'pinned'.
Renderers that don't provide built-in support for pinned curves can use this scene index to "expand" or "unpack" the authored data. This involves the following:
- Adding "phantom" points at the ends of each curve. For BSpline basis, each end point is repeated twice (so we have 3 consecutive identical points on each end) while for CatmullRom basis, each end point is repeated once. The topology is modified to reflect this.
- Expanding vertex primvars to account for the additional control points and varying primvars to account for the additional segments.
- Note
- This scene index does not convert indexed curves (i.e., with authored curve indices) into non-indexed curves.
Definition at line 55 of file pinnedCurveExpandingSceneIndex.h.