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Raytracing a Black Hole

rantonels.github.io

21–30 of 35 posts

Re: Raytracing a Black Hole

#21
post #8

On a related note, there's a paper by the Interstellar special effects team and Nobel laureate Kip Thorne describing how they rendered the black hole in the film and the tradeoffs they made: https://arxiv.org/abs/1502.03808

It's amazing that they put so much attention to detail in the same movie where a botched docking maneuver causes an orbiting spacecraft to fall out of the sky, and in which a black hole opens the way for programing mechanical watches from the past.

Re: Raytracing a Black Hole

#23
A fascinating topic. Another fascinating surface is a projective plane, that I've never managed to grasp. Any suggestions on how to visualize a travel on the surface of the projective plane?

Re: Raytracing a Black Hole

#24
post #20

I worked at dneg when this very shot was being rendered. From what I remeber there were a few steps to this being rendered, the first part was a massive particle sim. I was a systems engineer, so my job was to keep the system running. That particle sim ate at least 7, if not more hard disks. What ever it did, it destroyed 8tb HDDs. The worst part was we couldn't take that file server offline, as the render needed to…

Sometimes I think about what kind of yak shaving it takes to put together some menial technical detail, and I just throw the idea out, if it doesn't feel like the implementation is clean enough. If someone told me that in order to take a picture of some natural landscape, I'd have to throw 7 brand new 8TB hard drives in the garbage, in order to capture a 64 megapixel image, I'd say "not worth it." It challenges one's…

To put this in more context:

at the time there were 32 file servers, each with a 60 disk array attached. Thats almost 2000 spinny disks.

At that scale we'd expect about one failing disk every two weeks+. We were covered by a 24/7/365 4 hour warranty. This means that a replacement disk will appear within 4 hours, anytime of the year.

From what I understand the old disks are taken back, examined, refurbished and sent out again. I've heard that its often head alignmet, and or track setup issues that cause the most problems.

But yeah, there is waste....

+in practice we had a lot more disks than this, as we needed fast online backup. so we'd normally have at least two failed disks a week.

Re: Raytracing a Black Hole

#25

I worked at dneg when this very shot was being rendered. From what I remeber there were a few steps to this being rendered, the first part was a massive particle sim. I was a systems engineer, so my job was to keep the system running. That particle sim ate at least 7, if not more hard disks. What ever it did, it destroyed 8tb HDDs. The worst part was we couldn't take that file server offline, as the render needed to…

You're talking about a different black hole render. This is an original project that runs on consumer hardware.

Re: Raytracing a Black Hole

#26
post #8

On a related note, there's a paper by the Interstellar special effects team and Nobel laureate Kip Thorne describing how they rendered the black hole in the film and the tradeoffs they made: https://arxiv.org/abs/1502.03808

Compare Jean-Pierre Luminet's https://arxiv.org/abs/1804.03909 which discusses Interstellar starting at the bottom of the third page of the pdf.

Re: Raytracing a Black Hole

#27
post #21
post #8

On a related note, there's a paper by the Interstellar special effects team and Nobel laureate Kip Thorne describing how they rendered the black hole in the film and the tradeoffs they made: https://arxiv.org/abs/1502.03808

It's amazing that they put so much attention to detail in the same movie where a botched docking maneuver causes an orbiting spacecraft to fall out of the sky, and in which a black hole opens the way for programing mechanical watches from the past.

Please don't kill this movie for me. It still has rewatch value for spectacles. :)

Re: Raytracing a Black Hole

#28
post #9

I was rather confused by the section describing a "white and blue ... white and green" image that doesn't actually contain any green. Eventually... > The lower surface is blue and not green because I'm lazy Being lazy is fine (I've rendered zero black holes myself), but he could at least be consistent.

[deleted]

Re: Raytracing a Black Hole

#29
> Here we have an infinitely thin, flat, horizontal accretion disk extending from the photon sphere (this is very unrealistic, orbits below 3rS are unstable. More below) to 4 radii, coloured checkered white and blue on the top and white and green on the bottom. It is evident, with this colouring, that we've encountered another case of seeing 100% of something at the same time.

> For this image, I moved the observer up a bit, so he can take a better look at the disk. You can see two main images of the disk, one of the upper face, and one, inside, of the lower.

Wait, am I missing something? I don't see any green in the pictures.

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