private void parseNodeGroup(String key, String value) {
		switch(key) {
		case "Geometry":
			node.geometry = parseVector3f(value);
			break;
		case "BulkMaterial":
			node.bulkMaterial.add(parseMaterial(value));
			break;
		case "AnisoCarcassConductivityMult":
			node.anisoCarcassConductivityMult = parseVector3f(value);
			break;
		case "TreadDepth":
			node.treadDepth = Double.valueOf(value);
			break;
		case "TreadMaterial":
			node.treadMaterial.add(parseMaterial(value));
			break;
		case "RingAndRim":
			node.ringAndRim = parseDoubleList(value);
			break;
		case "PlyParams":
			ply = new Ply();
			ply.params = parsePlyParam(value);
			node.plies.add(ply);
			break;
		case "PlyMaterial":
			if(this.ply != null) {
				this.ply.materials.add(parseMaterial(value));
			}
			break;
		}
	}