What exactly is connectivity?

[jandrovins]

pyoctree.PyOctree(pointCoords,connectivity)

I'm trying to use your data structure to find collisions on a cloud of spheres. I have the coordinates of each point, but I do not understand what is the second parameter used for, nor why it is mandatory...

Am I just missing something?

[themmes]

@jandrovins Good question! Connectivity means the edges between the points of the mesh. I was hoping it wouldn't be needed too. However the library seems to be oriented towards ray intersection with meshes. From the README.md:

#pyoctree

Octree structure containing a 3D triangular mesh model. To be used for ray tracing / shadow casting.

[zdens]

still no answer:(
why should the length of connectivity be equaled to the length of the pointCoords?
one item in pointCoords is one point whereas one item in connectivity is one triangle, isn't it?
given the mesh of cube from 12 triangles we obtain 12*3 points...