e of a sphere
			const spherePositions = [];

			// for the second morph target, we'll twist the cubes vertices
			const twistPositions = [];
			const xAxis = new t3d.Vector3(1, 0, 0);
			const quaternion = new t3d.Quaternion();
			const vertex = new t3d.Vector3();

			for (let i = 0; i < positionAttribute.buffer.count; i++) {
				const x = positionAttribute.buffer.array[i * 3];
				const y = positionAttribute.buffer.array[i * 3 + 1];
				const z = positionAttribute.buffer.array[i * 3 + 2];

				spherePosit