From 1c85c2ecaa826afd8bf80f93741cf1b2deba5798 Mon Sep 17 00:00:00 2001 From: hachem Date: Mon, 24 Aug 2026 13:06:22 +0200 Subject: [docs]: remove duplicate --- README.md | 2 -- 1 file changed, 2 deletions(-) diff --git a/README.md b/README.md index 605123a..8898802 100644 --- a/README.md +++ b/README.md @@ -21,8 +21,6 @@ The curvature of spacetime changes the direction of each ray as it passes around ## Rendering For each pixel, Donut generates a ray from the camera using its position, orientation, field of view, and aspect ratio. The ray is then converted into the coordinates used by the geodesic integrator and propagated through the scene. During integration, the renderer checks for intersections with the black hole, accretion disk, and other scene objects. Rays that escape are sampled against the background environment. The accretion disk is a thin, opaque, self-luminous surface in the equatorial plane, with a Novikov–Thorne temperature profile that is hottest just outside the inner edge and cools outward, coloured as a redshifted blackbody; an optional turbulence overlay modulates its brightness. Its gas orbits at relativistic Keplerian speed (reaching half the speed of light at the innermost stable orbit), so the disk is Doppler-brightened on the side rotating toward the camera. Since the disk is viewed through curved spacetime, different parts of it can reach the camera along multiple paths around the black hole. The resulting image includes gravitational lensing, gravitational redshift, and Doppler shifting from the rotating disk. The final pixel color is determined from the ray's path, its intersection with the scene, and the relativistic effects accumulated along the way. The entire process runs on the GPU as a full-screen fragment shader, tracing every pixel's ray in parallel. -The full equations of motion, the accretion-disk and redshift models, and the integration scheme are documented in [docs/physics.md](docs/physics.md). - ## Documentation For a deeper explanation of how Donut works, see the [`docs/`](docs/) folder: - [docs/physics.md](docs/physics.md) — the physics and mathematics: null geodesics and the equations of motion, the numerical integrator, the event horizon / photon sphere / ISCO, the Novikov–Thorne accretion disk, gravitational + Doppler redshift and relativistic beaming, and the observable quantities the renderer can measure. -- cgit v1.3