in_volume treats volumes as convex hulls

[jefferis]

Uses scipy to test if points are within a given CATMAID volume. The idea is to test if adding the point to the cloud would change the convex hull.

Doesn't this implicitly assume that the volume is a convey hull? Think about the convex hull of the mushroom body which looks a bit like a pyramid. It seems to me that a point could be inside the pyramid but far outside the alpha shape defining the mushroom body and still pass this test.

[schlegelp]

Good point! Will see if I can use scipy.spatial.Delaunay instead.

[schlegelp]

Found a library that does has no external dependency which uses Octrees to intersect rays with volumes: pyoctree (https://github.com/mhogg/pyoctree)

For example see here

Initial tests look promising. Will run some more to check performance before implementing.

[schlegelp]

Implemented with commit ba4b266