Gravitational lensing near a Schwarzschild black hole, with Einstein rings and the photon sphere
Raymarching geodesics in the Schwarzschild spacetime metric surrounding a non-rotating black hole. Light rays are bent by the curved spacetime, producing gravitational lensing, Einstein rings, and the photon sphere. The numerical integration follows null geodesics of the Schwarzschild metric.
Controls: WASD to rotate, arrow keys to translate.
