function getChildByName(node, name) {
                return node.getChildMeshes(false, function (n) { return n.name === name; })[0];
            }
Takes a list of meshes (as loaded from the glTF file) and finds the root node, as well as nodes that
can be transformed by button presses and axes values, based on this._mapping.

@param scene scene in which the meshes exist
@param meshes list of meshes that make up the controller model to process
@return structured view of the given meshes, with mapping of buttons and axes to meshes that can be transformed.