I did not get the source code, I wonder how to get the closest primitive, in fact it is a triangle, if I want to get the nearest point with another, just use their
Euler distance, but how to get the nearest primitive with specific point?
If you want to get the closest point and the closest primitive to a specific point, you can use the function closest_point_and_primitive()
of the AABB-tree.
See a usage example here