code: def update_positions(self, positions):
          '''Update the sphere positions.
          '''
          sphs_verts = self.sphs_verts_radii.copy()
          sphs_verts += positions.reshape(self.n_spheres, 1, 3)
  
          self.tr.update_vertices(sphs_verts)
          self.poslist = positionf update_positions(self, positions):
          '''Update the sphere positions.
          '''
          sphs_verts = self.sphs_verts_radii.copy()
          sphs_verts += positions.reshape(self.n_spheres, 1, 3)
  
          self.tr.update_vertices(sphs_verts)
          self.poslist = positions
docs: Update the sphere positions.