A class containing useful utility functions for scene manipulation.
geometry -- The geometry for the set of materials.
materials -- The materials for the object.
Creates a new Group that contains a new mesh for each material defined in materials. Beware that this is not the same as an array of materials which defines multiple materials for 1 mesh.
This is mostly useful for objects that need both a material and a wireframe implementation.
[link:https://github.com/mrdoob/three.js/blob/master/examples/js/utils/SceneUtils.js examples/js/utils/SceneUtils.js]