Hi, I am new to using PyMesh. I am trying to perform Boolean operations on basic polyhedra, e.g. intersection of two cubes. However I am finding that pymesh.boolean() rejects any basic 3D shape I give it, reporting "Input mesh is not PWN!".

For example, consider the two trials below. The call to pymesh.boolean works fine for the intersection of two triangles in 2D, but fails for the same task with two tetrahedra in 3D, claiming the input mesh is not PWN. I am not familiar with the concept of PWN (piece-wise constant winding number) but it is counterintuitive to me that this most basic shape is not eligible for boolean operation. Can anyone spot the error?