7 ms·

Show HN: Ball falls on the teapot in WebGL

49 points by alex2401 10y ago

barnacs 10y ago
For some reason I was expecting a bowling ball to fall and crush the teapot. More like: http://bit.ly/2bhClHV http://bit.ly/2bhClHV
- 56k 10y ago
  I thought it was going to fall inside the teapot.
  - odabaxok 10y ago
    Set the y coordinate of the sphere to 96.. ;)
    - doodpants 10y ago
      Better yet, set the X coordinate of the sphere to 94
      - odabaxok 10y ago
        Sorry, you are right, X should be set to 94-ish.
- Retr0spectrum 10y ago
  Now I was expecting that link to show the teapot getting crushed...
deleted 10y ago
[deleted]
patmcguire 10y ago
I see cool demos, and things that look passable for game graphics http://alexis.lart.no/emh/snapshots/rts-free.git/ http://alexis.lart.no/emh/snapshots/rts-free.git/ Is there some big use of WebGL in production that I'm missing? It always seems to have a bunch of promise that no one does much new with
- skoczymroczny 10y ago
  The popularity should spike soon, because Unity3D Webplayer has been deprecated a while ago and WebGL is the official Unity3D distribution method for the web. The performance isn't there yet, but authors promise to get there at some point.
  - iLoch 10y ago
    Unity on WebASM looks really solid though. I'm expecting that's what they're going to be focusing on in the coming years.
- RamshackleJ 10y ago
  google maps
lagadu 10y ago
Curiously enough, the first time I ran it it was "teapot falling on ball" instead. It slowly slid off the ball after it landed. Still worked fine :)
zachrose 10y ago
Sometimes the ball bounces off the spout and rolls down towards the camera. Other times it rolls aways from the camera. Can anyone speculate on why this is apparently non-deterministic?
- edvinbesic 10y ago
  Probably due to rounding errors (multiplication precision) [1]: http://floating-point-gui.de/ http://floating-point-gui.de/
  - chc 10y ago
    Why would the results of floating point math be inconsistent between consecutive runs of the same program?
    - edvinbesic 10y ago
      Hmm, good point. Probably rules that out you're right. Maybe it's the way the timer is handled when computing the physics, since they would have to compute the deltas based on previous step and the timers in JS are not exact maybe they are producing slightly different deltas between frames accumulating to the difference.
  - deleted 10y ago
    [deleted]
  - sevenless 10y ago
    This is a ridiculous question, but could quantum mechanical uncertainty be interpreted as a rounding error? Say the universe only stores a certain number of bits of information for each particle...
    - devopsproject 10y ago
      Aren't the number of particles the deciding factor? If you had 100 particles, you couldn't give me exactly 1/3 of them.
dschuetz 10y ago
My first impression: doesn't work. I'm on Safari 9 with enabled WebGL. Wonderful.
- nsxwolf 10y ago
  I never try to use Safari for WebGL. I just assume it isn't supported or so broken it might as well not be.
- blueline 10y ago
  doesn't work on safari technology preview 11 either
kempbellt 10y ago
Set gravity of X to 1. Win! Seriously though. Very cool demo. Great work.
- natosaichek 10y ago
  If you set X gravity to 80, it's even cooler. :-D
  - SparkyMcUnicorn 10y ago
    I like -12 best.
partycoder 10y ago
Interesting. Seems to be non-deterministic. Each time the ball falls to a different side.
- devopsproject 10y ago
  floating point rounding errors
  - frgewut 10y ago
    Floating point rounding errors are deterministic.
    - devopsproject 10y ago
      in math, yes in computers, yes and no. read: https://randomascii.wordpress.com/2013/07/16/floating-point-determinism/ https://randomascii.wordpress.com/2013/07/16/floating-point-...
  - partycoder 10y ago
    I wonder if it rather has to do with clocks (discretizing the simulation steps). Probably in a real-time system it might be deterministic?

49 points by alex2401 10y ago

For some reason I was expecting a bowling ball to fall and crush the teapot. More like: http://bit.ly/2bhClHV http://bit.ly/2bhClHV

56k 10y ago
I thought it was going to fall inside the teapot.
- odabaxok 10y ago
  Set the y coordinate of the sphere to 96.. ;)
  - doodpants 10y ago
    Better yet, set the X coordinate of the sphere to 94
    - odabaxok 10y ago
      Sorry, you are right, X should be set to 94-ish.
Retr0spectrum 10y ago
Now I was expecting that link to show the teapot getting crushed...

deleted 10y ago

[deleted]

patmcguire 10y ago

I see cool demos, and things that look passable for game graphics http://alexis.lart.no/emh/snapshots/rts-free.git/ http://alexis.lart.no/emh/snapshots/rts-free.git/ Is there some big use of WebGL in production that I'm missing? It always seems to have a bunch of promise that no one does much new with

skoczymroczny 10y ago
The popularity should spike soon, because Unity3D Webplayer has been deprecated a while ago and WebGL is the official Unity3D distribution method for the web. The performance isn't there yet, but authors promise to get there at some point.
- iLoch 10y ago
  Unity on WebASM looks really solid though. I'm expecting that's what they're going to be focusing on in the coming years.
RamshackleJ 10y ago
google maps

lagadu 10y ago

Curiously enough, the first time I ran it it was "teapot falling on ball" instead. It slowly slid off the ball after it landed. Still worked fine :)

zachrose 10y ago

Sometimes the ball bounces off the spout and rolls down towards the camera. Other times it rolls aways from the camera. Can anyone speculate on why this is apparently non-deterministic?

edvinbesic 10y ago
Probably due to rounding errors (multiplication precision) [1]: http://floating-point-gui.de/ http://floating-point-gui.de/
- chc 10y ago
  Why would the results of floating point math be inconsistent between consecutive runs of the same program?
  - edvinbesic 10y ago
    Hmm, good point. Probably rules that out you're right. Maybe it's the way the timer is handled when computing the physics, since they would have to compute the deltas based on previous step and the timers in JS are not exact maybe they are producing slightly different deltas between frames accumulating to the difference.
- deleted 10y ago
  [deleted]
- sevenless 10y ago
  This is a ridiculous question, but could quantum mechanical uncertainty be interpreted as a rounding error? Say the universe only stores a certain number of bits of information for each particle...
  - devopsproject 10y ago
    Aren't the number of particles the deciding factor? If you had 100 particles, you couldn't give me exactly 1/3 of them.

dschuetz 10y ago

My first impression: doesn't work. I'm on Safari 9 with enabled WebGL. Wonderful.

nsxwolf 10y ago
I never try to use Safari for WebGL. I just assume it isn't supported or so broken it might as well not be.
blueline 10y ago
doesn't work on safari technology preview 11 either

kempbellt 10y ago

Set gravity of X to 1. Win! Seriously though. Very cool demo. Great work.

natosaichek 10y ago
If you set X gravity to 80, it's even cooler. :-D
- SparkyMcUnicorn 10y ago
  I like -12 best.

partycoder 10y ago

Interesting. Seems to be non-deterministic. Each time the ball falls to a different side.

devopsproject 10y ago
floating point rounding errors
- frgewut 10y ago
  Floating point rounding errors are deterministic.
  - devopsproject 10y ago
    in math, yes in computers, yes and no. read: https://randomascii.wordpress.com/2013/07/16/floating-point-determinism/ https://randomascii.wordpress.com/2013/07/16/floating-point-...
- partycoder 10y ago
  I wonder if it rather has to do with clocks (discretizing the simulation steps). Probably in a real-time system it might be deterministic?