Yes, which is why the light cone is actually described as a 4D object that exists in spacetime, not a 3D sphere. Some back of the envelope calculation indicate

Yes, which is why the light cone is actually described as a 4D object that exists in spacetime, not a 3D sphere. Some back of the envelope calculation indicates that the spacetime "volume" of the light cone of an object is 1/8th of the spacetime volume of the universe up to that point. So using the light cone would net you an 8x speedup over a brute-force Universe render. Nothing to write home about if you have infinite computing power.