Real-time ray tracing rendering accretion disk of a Schwarzschild black hole

Real-time rendered accretion disk of a Schwarzschild black hole with relativistic Doppler effect and intensity boosting effect, implemented in CUDA and OpenGL (C++). Each pixel traces a null geodesic through the Schwarzschild metric using a 4th-order Runge-Kutta integrator, producing an accretion disk with animated texture. Part of the accretion disk red/blue shifts out of visible light band. The photon ring is visible at 1.5 radius of the event horizon. Benchmarked on an NVIDIA® GeForce RTX 4060 Ti: 1280×720 resolution at 30 FPS. [GitHub repository] [Derivation of geodesic equation]