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From Slowchop Studios:
Gravit is visually stunning gravity simulator, where you can spend many hours of fun and experimentation. It simulates the N-body problem using the Barnes-Hut Algorithm.** NOTE ** There is a bug with the keyboard controls. You must hold down the "fn" key when pressing the function keys (F1-F12). Press: - fn-F8 to start a new simulation - fn-F6 to start recordingThis will be fixed very soon, with on-screen buttons.Many features including: - It looks pretty and is easy to use. - View the simulation in 3D using stereoscopic imaging! - You can record, then play back at any speed - Stores every particle's position for every frame in memory - Compresses history when needed, for very long recordings - Mouse controllable rotation - Colours can be based on mass, velocity, acceleration, momentum or kinetic energy - See an octtree being created in real-time - Save/Load functionality - Update display/input while recording a frame