Learning Null Geodesics for Gravitational Lensing Rendering in General Relativity

Mingyuan Sun, Zheng Fang, Jiaxu Wang, Kunyi Zhang, Qiang Zhang, Renjing Xu; Proceedings of the IEEE/CVF International Conference on Computer Vision (ICCV), 2025, pp. 28473-28482

We present GravlensX, an innovative method for rendering black holes with gravitational lensing effects using neural networks. The methodology involves training neural networks to fit the spacetime around black holes and then employing these trained models to generate the path of light rays affected by gravitational lensing. This enables efficient and scalable simulations of black holes, significantly decreasing the time required for rendering compared to traditional methods. We validate our approach through extensive rendering of multiple black hole systems with superposed Kerr metric, demonstrating its capability to produce accurate visualizations with significantly 15x reduced computational time. Our findings suggest that neural networks offer a promising alternative for rendering complex astrophysical phenomena, potentially paving a new path to astronomical visualization.