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How would I recreate the Gargantua Blackhole scene in Unity?

Discussion in 'World Building' started by the_Bad_Brad, Aug 24, 2018.

  1. the_Bad_Brad

    the_Bad_Brad

    Joined:
    Nov 2, 2014
    Posts:
    278
    I mean that blackhole scene from the movie Interstellar

    I do not know where to start. All I know is just place a plane with a transparent texture resembling a blackhole and then rotate it overtime.
     
  2. newjerseyrunner

    newjerseyrunner

    Joined:
    Jul 20, 2017
    Posts:
    966
    A black hole is a region of space that contains an event horizon. It's the most perfectly spherical "object" in the entire universe, so a simple billboard that always faces the camera would be sufficient for the hole.

    What frequency of light are you trying to emulate? The only part of a black hole that produces any light is the accretion disc, which will glow white hot, and gradually fade to red, then black over the range of several light hours. Accretion discs tend to be halo shaped, but it also produces super-energetic jets at either pole of the black hole, which will likely not be visible.

    The biggest problem with displaying a black hole is the geodesics. You're going to have to write a shader that will bend light around it and doppler shift it. I'd precalculate the bend offset into a texture and use that to determine offset. Are you familiar with the equations of general relativity? You'd have to calculate the Ricci curvature tensor and then integrate out the geometry of spacetime.

    I'm curious what you mean by rotate over time and how big your black hole is. Black hole rotation is weird because it's about angular momentum and the dragging of space itself, they don't rotate in the traditional sense, it's more like a quantum spin. Frame dragging can create some weird ripple effects and stripes in the Doppler shift, but shouldn't take any extra work since that's all worked into the equations of general relativity.

    I seem to remember that the BH in the movie wasn't actually all that big. It was a stellar mass black hole a few times the mass of our sun. Black holes grow orders of magnitude larger.

    All in all, I see no reason why you couldn't create a convincing black hole.
     
    Last edited: Aug 28, 2018
  3. the_Bad_Brad

    the_Bad_Brad

    Joined:
    Nov 2, 2014
    Posts:
    278
    Thanks for the info. I will just do that on a animation software and render the animation into a high-res video file and then put a huge plane in the background that will display the video file. I just have to mask the edges. Since it is huge, it should never leave the camera. It is just a place holder that is part of a cutscene.
     
    newjerseyrunner likes this.