face count, integer
the number of faces in a mesh
face topology, array of 8 bit unsigned integers
each entry at index i corresponds to face i the value of the entry is the arity of the face; i.e. a triangle is 3 and a quad is 4
face array
an array of integer tuples, arity indicated per tuple by the face count array, where each tuple is the vertex indices, in ccw order, describing a face
holes
hole array, array of unsigned integers
The value of an entry in the holes array indicates the index of a face that is a hole
edge creases
array of tuple of int, int, float Each entry refers to two vertex indices comprising an edge, and a weight between 0 and 1 indicating the amount of creasing
vertex creases
array of tuple of int, float Each entry refers to a vertex index, and a weight between 0 and 1 indicating the amount of creasing
method
Enumerated value indicating one of the subdivision rules, Catmull-Clark, or Loop, or Hybrid Catmull-Clark/Loop
boundary interpolation rules
Boundary interpolation rules control how subdivision and the limit surface behave for faces adjacent to boundary edges and vertices None, Edge Only, Boundary Edge and Corner
Face varying interpolation rules FVAR_LINEAR_NONE smooth everywhere the mesh is smooth FVAR_LINEAR_CORNERS_ONLY linearly interpolate (sharpen or pin) corners only FVAR_LINEAR_CORNERS_PLUS1 CORNERS_ONLY + sharpening of junctions of 3 or more regions FVAR_LINEAR_CORNERS_PLUS2 CORNERS_PLUS1 + sharpening of darts and concave corners FVAR_LINEAR_BOUNDARIES linear interpolation along all boundary edges and corners FVAR_LINEAR_ALL linear interpolation everywhere (boundaries and interior)
For further information, please see https://graphics.pixar.com/opensubdiv/docs/intro.html