black_hole

Usage Guide

Running the Simulation

Navigate to your build directory where the executables are located.

3D Simulation

Run the main executable:

./black_hole

(On Windows, this might be .\Debug\black_hole.exe)

2D Lensing Demo

Run the 2D ray tracer:

./2D_lensing

Controls (3D Simulation)

Camera Movement

Action	Control	Description
Orbit	Left Mouse Button + Drag	Rotate camera around the black hole.
Zoom In	Scroll Up	Move closer to the black hole.
Zoom Out	Scroll Down	Move further away.
Pan	Shift + Left Mouse (or Middle Mouse)	Pan the camera view (note: camera attempts to stay centered on the black hole).

Simulation Toggles

Key	Function	Description
G	Toggle Gravity	Turns N-body gravity on/off for orbiting objects (not the light rays, those are always affected).
Right Click	Hold for Gravity	Temporarily enable gravity while held.

Understanding the View

• Black Realm: The region inside the event horizon ($r < r_s$) from which no light can escape.
• Accretion Disk: The glowing ring of matter. You will notice one side is brighter (Doppler beaming) and the back side of the disk is visible above and below the black hole due to gravitational lensing.
• Einstein Ring: If you align the camera perfectly with a background object, it generates a ring of light.
• Grid: The coordinate grid visualizes the warping of space. Near the event horizon, the grid lines plunge downwards, illustrating the “infinite well” potential.