Kerr black hole visualizer and Kerr geodesics simulator in Javascript with WebGL.
Reference:
- Radiation transfer of emission lines in curved space-time, S. V. Fuerst, K. Wu, A&A 424 (3) 733-746 (2004), DOI: 10.1051/0004-6361:20035814
- The Mathematical Theory of Black Holes, S. Chandrasekhar, Clarendon Press, Oxford Classic Texts in the Physical Sciences