Non-linear Monte Carlo Ray Tracing for Visualizing Warped Spacetime
Avirup Mandal*
Kumar Ayush*
Parag Chaudhuri
[Paper PDF]


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 these light 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 create plausible visualizations of what happens when a black hole appears in a more known environment, like a room with regular specular and diffuse surfaces. We demonstrate that our solution is correct at cosmological scales by showing how spacetime warps around a stationary Schwarzschild black hole and a non-stationary Kerr black hole. We verify that the solution is consistent with the predictions of general relativity. In the absence of any curvature in spacetime, our renderer behaves like a normal linear ray tracer. Our method has the potential to create rich , physically plausible visualizations of complex phenomena that can be used for a range of purposes, from creating visual effects to making pedagogical aids to understand the behaviour of spacetime as predicted by general relativity.

Paper and Supplementary Material

A. Mandal*, K. Ayush*, and P. Chaudhuri. (* Equal contribution).
Non-linear Monte Carlo Ray Tracing for Visualizing Warped Spacetime. (Shortlisted for Best Paper Award).
International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - IVAPP. 2021.
[Paper PDF][Paper PPT]
[IVAPP (Publisher) version]



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