PBVH¶
Sculpt mode uses a coarse BVH tree, PBVH. The leaves are fairly
large compared to most BVHs; this is because the leaves are used to
split the GPU mesh.
Data modes¶
PBVH has three different modes, each of which has a different data backing:
You get can the mode with BKE_pbvh_type.
Vertex/Face references¶
The PBVH API stores vertex references in a special structure,
PBVHVertRef. It contains a single intptr_t value, the meaning of
which varies by PBVH data mode. PBVH_BMESH stores pointers in the
value, while the other two store indices. The null reference is
PBVH_REF_NONE.
Vertex Iteration¶
You can iterate over the vertices in a PBVHNode. There are two modes
for this, PBVH_ITER_UNIQUE and PBVH_ITER_ALL.
PBVH_ITER_UNIQUE iterates over the vertices uniquely assigned to
this node, while PBVH_ITER_ALL iterates over the vertices that
belong to this node's faces.
PBVHVertIter vd;
BKE_pbvh_vertex_iter_begin(pbvh, node, vd, PBVH_ITER_UNIQUE) {
//PBVHVertIter has various bits of data:
//vd.co - position
//vd.no - normal
//vd.mask - pointer to mask
//vd.color - active color attribute data, if it exists
}
BKE_pbvh_vertex_iter_end;