code: def vertex(self, points):
          
          tree = self._mesh.kdtree
          return tree.query(points)
docs: Given a set of points, return the closest vertex index to each point
  
          Parameters
          ----------
          points : (n,3) float, list of points in space
  
          Returns
          ----------
          distance  : (n,) float, distance from source point to vertex
          vertex_id : (n,) int, index of mesh.vertices which is closest