Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

marctenbosch.com

Post reply on HN
Print view View original

71–80 of 101 posts

Re: 4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

#71

Post by Random_ernest »

mschuetz wrote: post #25
thanatropism wrote: post #23

Earlier quoted context omitted.

A classical particle (think a pebble) exists in 6 dimensions, 3 positions and 3 momenta. Nothing (in the classical, non-quantum) setting is solely determined by position coordinates.

I forgot most of the details already but as far as I remember, some classes of splines are 4 dimensional constructs that are then projected to 3 dimension to get your 3d spline curve.

What you are referring to is used in e.g. CAD modelling, we call them non-uniform rational B-splines or NURBS.

Recently there has been super interesting research on using these nurbs as ansatzfunctions e.g. for FEM stuff. They got a lot of applications.

Re: 4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

#73

Post by slowhadoken »

anigbrowl wrote: post #40
throwaway_pdp09 wrote: post #19

I am genuinely surprised for a long time that I've not seen 4D monsters in films. It has been so obvious to me there's potential there. It would of course be a flat 2D projection of a 3D slice through a 4D creature, so it would look like a smoothly morphing between different creatures, and in and out of existence so we've sort of had morphing for a long while (since Willow, C. 1985) but... there's potential. In case…

Annihilation (2018) Spoiler, obviously: https://www.youtube.com/watch?v=uBsJgceM0KI - if you haven't seen it cannot recommend it highly enough, just wait and watch the whole thing.

Yeah it’s just a Mandelbulb Fractal. Here’s one made with Blender Eevee @ https://m.youtube.com/watch?v=YtDG1_76_2k

Re: 4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

#75

Post by tnolet »

Random_ernest wrote: post #70
throwaway_pdp09 wrote: post #19

I am genuinely surprised for a long time that I've not seen 4D monsters in films. It has been so obvious to me there's potential there. It would of course be a flat 2D projection of a 3D slice through a 4D creature, so it would look like a smoothly morphing between different creatures, and in and out of existence so we've sort of had morphing for a long while (since Willow, C. 1985) but... there's potential. In case…

In the Hyperion books by Dan Simmons there is a being that can move in higher dimensions and the books will reportedly get a movie. Maybe they will adapt some effects like this.

Was about to post this. The Hyperion saga is an absolute must for hard SF freaks. If you like the three body problem, you’ll love this too.

The 4D creature mentioned by parent is amazing. There are more 4D puzzles like a temple moving back through time.

Re: 4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

#76

Post by jimmySixDOF »

LolWolf wrote: post #24
guardian5x wrote: post #10

I would like to see the 4th dimension projected into 3d and not just a slide, same as you could project the 3d into 2d, by showing further objects smaller and closer objects bigger.

You can absolutely do this (and it would be quite interesting to try with a VR headset, e.g.!); the idea is a special case of the projective transform [0] in 4 dimensions. It may make for a cool demo. ----- [0] https://en.wikipedia.org/wiki/Homography

Absolutely this should be in VR and I'm a little bit surprised it isn't tbh

edit: [1] https://4dtoys.com

Re: 4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

#77

Post by throwaway_pdp09 »

slowhadoken wrote: post #73
anigbrowl wrote: post #40

Earlier quoted context omitted.

Annihilation (2018) Spoiler, obviously: https://www.youtube.com/watch?v=uBsJgceM0KI - if you haven't seen it cannot recommend it highly enough, just wait and watch the whole thing.

Yeah it’s just a Mandelbulb Fractal. Here’s one made with Blender Eevee @ https://m.youtube.com/watch?v=YtDG1_76_2k

I would have preferred not to know that. As the parent post said, spoiler.

Re: 4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

#78

Post by Yajirobe »

anigbrowl wrote: post #40
throwaway_pdp09 wrote: post #19

I am genuinely surprised for a long time that I've not seen 4D monsters in films. It has been so obvious to me there's potential there. It would of course be a flat 2D projection of a 3D slice through a 4D creature, so it would look like a smoothly morphing between different creatures, and in and out of existence so we've sort of had morphing for a long while (since Willow, C. 1985) but... there's potential. In case…

Annihilation (2018) Spoiler, obviously: https://www.youtube.com/watch?v=uBsJgceM0KI - if you haven't seen it cannot recommend it highly enough, just wait and watch the whole thing.

And which part exactly is 4D?

Re: 4D Toys: how objects bounce and roll in 4D – paper accepted to SIGGRAPH 2020

#79

Post by Yajirobe »

pujjad wrote: post #15
jayd16 wrote: post #9

I'll ask any physicists out there. A 4th spatial dimension probably doesn't exist, right? Even if we couldn't perceive shapes across a 4th dimension, we would still perceive things moving through the 4th dimension like we see in 4D toys. In reality we don't ever see anything like this (spatially anyway). Is that correct?

If there were 4 spatial dimensions + 1 time dimension we would end up in an unstable universe. Ehrenfest (1917/1920) studied the hydrogen in n dimensions and concluded for n> 3 that neither classical atoms nor planetary orbits can be stable, because the inverse square law of electrostatic and gravity becomes an inverse cube law. When n > 3 there are no stable orbits to the two body problem: an incoming light body att…

Hooray! We disproved string theory!
Post reply on HN