cortex.polyutils.Surface.extract_chunk

Surface.extract_chunk(nfaces=100, seed=None, auxpts=None)

Extract a chunk of the surface using breadth-first search, for testing purposes.

Starting from seed (or a random vertex), grows a set of faces by breadth-first traversal of face adjacency until at least nfaces faces have been collected, then returns the sub-mesh induced by those faces with vertex indices remapped to be contiguous.

Parameters:

nfacesint, optional

Minimum number of faces to include in the extracted chunk. Default is 100.

seedint, optional

Vertex index to start the breadth-first search from. If None (default), a random vertex is chosen.

auxptsndarray, optional

Auxiliary per-vertex data (e.g. an alternate set of point coordinates) to subset and return alongside the chunk.

Returns:

ptsndarray

Vertex coordinates of the extracted chunk.

auxndarray

Corresponding rows of auxpts for the extracted chunk’s vertices. Only returned if auxpts is not None.

polysndarray

Triangle faces of the extracted chunk, as indices into pts.