Unreal Engine 4 : Black Hole : Volumetric Accretion Disk : Jumping Into The Future

Описание

Real-time rendering with Unreal Engine 4 of some effects related to special and general relativity. Relativistic aberration of light and Doppler beaming are modeled according to the equations of special relativity. Gravitational lensing is not physically accurate since it is modeled by equations unrelated to general relativity and with the assumption that light propagates instantaneously.

Orbital motion is modeled by Newtonian mechanics implemented by the physics engine. So in terms of physics in this video, orbiting objects move around a spherical dark star, an object compatible with Newtonian mechanics that has a surface escape velocity that equals or exceeds the speed of light. The radius of the dark star in this video is 3000 m. The speed of light is greatly reduced and is taken equal to 9000 m/s.

The beacon time displayed on the HUD is related to the proper time of the big clock mounted on the asteroid. The radial coordinate and apsides are indicated in fractions of the dark star radius. The orbital speed is indicated in fractions of the speed of light.

Although Newtonian mechanics and general relativity treat gravity quite differently, the equations of motion of Newtonian mechanics are the limiting case in general relativity for weak fields and velocities of motion much less than the speed of light. The task of describing motion is greatly simplified for binary systems, in which the mass and the size of one body can be neglected in comparison with another very massive and spherically symmetric body. In such binary systems, one can assume that the smaller body moves as a so-called test particle in the gravitational field generated by the larger body. In this case, in Newtonian mechanics, the motion of a test particle is a Kepler orbit, while in general relativity, the motion is described by the equations of the geodesic in a curved spacetime.
Kepler orbit: https://www.desmos.com/calculator/h7v1r3m7wh
Here you can compare orbits of test particles in Newtonian mechanics and in the Schwarzschild metric: https://www.desmos.com/calculator/vbrl2jzmho

On the Unreal Engine Marketplace page, you can find the download link for the playable demo:
https://www.unrealengine.com/marketplace/en-US/product/black-hole-volumetric

The mesmerizing music of Vangelis from the album Rosetta (https://youtu.be/l_mLrRMlT-w):
Origins (Arrival);
Starstuff;