newton is open source now!

Please don't post Bullet support questions here, use the above forums instead.
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bert
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newton is open source now!

Post by bert »

http://newtondynamics.com/forum/viewtop ... 765#p45765

newton got released under the same license as bullet! :)

i think it's an interesting alternative to bullet. similar features but force based instead of impulse based.

what do you think?
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Erwin Coumans
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Re: newton is open source now!

Post by Erwin Coumans »

That is good news, nice to see that Julio chose to make Newton open source under the permissive zlib license.

Sharing ideas and implementation is good for game developers and for all projects related to game/movie physics. Rather than competing, the open source engines (ODE, Bullet, Newton) can benefit from eachother.

Thanks for letting us know.
bone
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Joined: Tue Feb 20, 2007 4:56 pm

Re: newton is open source now!

Post by bone »

Can anyone summarize in a sentence or two what exactly the Newton solver does? From their main page, it says, "Our engine implements a deterministic solver, which is not based on traditional LCP or iterative methods, but possesses the stability and speed of both respectively."
KenB
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Re: newton is open source now!

Post by KenB »

bert wrote:http://newtondynamics.com/forum/viewtop ... 765#p45765

newton got released under the same license as bullet! :)

i think it's an interesting alternative to bullet. similar features but force based instead of impulse based.

what do you think?
Given that both use discrete time, the difference between an impulse and a force is a constant - the timestep, dt.
So, all in all, this force vs impulse vs velocity based physics is just a matter of confusion and reluctance to use real math to describe the problem.

Speaking of Newton, I am very curious about the statement "Our engine implements a deterministic solver, which is not based on traditional LCP or iterative methods, but possesses the stability and speed of both respectively.".
Erin Catto
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Re: newton is open source now!

Post by Erin Catto »

I think the distinction should be between velocity versus acceleration constraints instead of impulses versus forces. In other words, does the engine try to solve acceleration constraints? Baraff showed that satisfaction of acceleration constraints can lead to infinite constraint forces. A typical physics engine does not attempt to satisfy acceleration constraints, leading to finite constraint forces. The downside is that we are restricted to a first order integrator.

That said, I don't know if Newton uses velocity or acceleration constraints.
Danisk
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Joined: Fri Mar 25, 2011 8:26 pm

Re: newton is open source now!

Post by Danisk »

i've been looking into bullet and newton, the thing is that newton has been updated way too much lately

i mean there's like 2-3 new version each month but meanwhile the tutorial aren't up to date at all and each time you go on the forum for question etc ... julio's answer look just like these "sry man i don't have time i'm working too much"

when searching for an engine i found newton quite easily at least more easily than bullet but the lack of up to date tutorial and documentation make it quite hard to use now

although i've just begin to look into bullet which i still quite don't understand too but seems that at least there's information to get everywhere
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