public static void trimBoneWeights(IrMesh mesh) {
        for (IrPolygon polygon : mesh.polygons) {
            for (IrVertex vertex : polygon.vertices) {
                trimBoneWeights(vertex);
            }
        }
    }
Removes low bone weights from mesh, leaving only 4 bone weights at max.

@param mesh the IrMesh to modify (not null)
jme3-plugins/src/main/java/com/jme3/scene/plugins/IrUtils.java