Abstract
General relativity describes the curvature of spacetime. Rays of light follow geodesic paths in curved space-time. Visualizing scenes containing spacetime regions with pronounced curvature requires tracing of theselight ray paths. We present a Monte Carlo approach for non-linear raytracing to render scenes in curved space-time. In contrast to earlier work, we can accurately resolve ray-object interactions. This allows us to createplausible visualizations of what happens when a black hole appears in a more known environment, like a roomwith regular specular and diffuse surfaces. We demonstrate that our solution is correct at cosmological scalesby showing how spacetime warps around a stationary Schwarzschild black hole and a non-stationary Kerrblack hole. We verify that the solution is consistent with the predictions of general relativity. In the absenceof any curvature in spacetime, our renderer behaves like a normal linear ray tracer. Our method has the poten-tial to create rich, physically plausible visualizations of complex phenomena that can be used for a range ofpurposes, from creating visual effects to making pedagogical aids to understand the behaviour of spacetime aspredicted by general relativity.