I'm not exactly sure what to take from that link. Is it recommending the use of a constant time step value instead of using what's supplied to love.update? I'm not using any kind of gravity in my test. The only other thing I can figure is that because I'm using the timestep supplied from love.update, the ball collides with the wall (and possibly bites into it a bit?) resulting in inconsistent contact points. Is that possible?
Also, since box2d is non-deterministic, if I have 2 worlds (1 simulation, 1 actual), doesn't that mean the simulation might not actually prove to be true?
Thanks for the replies!
Predicting path of a body/shape
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- Taehl
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Re: Predicting path of a body/shape
Box2D is non-deterministic, even with a fixed timestep?
Earliest Love2D supporter who can't Love anymore. Let me disable pixel shaders if I don't use them, dammit!
Lenovo Thinkpad X60 Tablet, built like a tank. But not fancy enough for Love2D 0.10.0+.
Lenovo Thinkpad X60 Tablet, built like a tank. But not fancy enough for Love2D 0.10.0+.
Re: Predicting path of a body/shape
I guess I'm not sure, I was just going off of what ivan said earlier.
Re: Predicting path of a body/shape
Actually with the constant time step the collisions seem to be consistent. Going to give the simulation a try w/ that
Re: Predicting path of a body/shape
The Box2D documation says that you should use a constant timestep.arahlf wrote:I'm not exactly sure what to take from that link. Is it recommending the use of a constant time step value instead of using what's supplied to love.update?
I think that some joints may become unstable when your timestep varies too much.
You probably won't notice any difference when your simulation constists of a finite number of billiard balls and you're not trying to predict what happens too far ahead.arahlf wrote:Also, since box2d is non-deterministic, if I have 2 worlds (1 simulation, 1 actual), doesn't that mean the simulation might not actually prove to be true?!
I'm pretty sure that - yes even with a fixed timestep the simulation might differ each time.Taehl wrote:Box2D is non-deterministic, even with a fixed timestep?
I have to look it up though, not sure if this is caused by how the Box2D solver works or if it's a rounding issue.
- bartbes
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Re: Predicting path of a body/shape
In any case you can't trust it to be the same.
(Of course the question arises whether this needs to be completely accurate.)
(Of course the question arises whether this needs to be completely accurate.)
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