Maybe an error in Bender&Trinkle's recent paper?

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shikui08
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Maybe an error in Bender&Trinkle's recent paper?

Post by shikui08 »

I am reading Bender&Trinkle's recent paper ' Interactive Simulation of Rigid Body Dynamics in Computer Graphics' . This paper could be found here : https://code.google.com/p/bullet/downlo ... e=STAR.pdf

The Equation(28) of this paper is slightly different, from equation(20) from an earlier paper from Trinkle 'Formulation of Multibody Dynamics As Complementarity Problems'. PDF version can be found here:https://www.cs.rpi.edu/twiki/pub/Roboti ... detc03.pdf

Both of these equations are derived by differentiating the holonomic constraint twice with respect to t. I can understand equation(20) of the DETC2003 paper with no problem. But equation(28) of Bender&Trinkle's paper, I think it is flawed. Here is my reasoning:https://skydrive.live.com/?cid=98b8c437 ... 7E3E51!672
So, any clue?
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Erwin Coumans
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Re: Maybe an error in Bender&Trinkle's recent paper?

Post by Erwin Coumans »

There could be a typo in equation 28 of the paper.

Can you replace the first term of k

Code: Select all

dC/dq dH/dt
by

Code: Select all

d( dC/dq H )/dt
and see if that helps?
Thanks!
Erwin
shikui08
Posts: 2
Joined: Sun Nov 18, 2012 12:12 pm

Re: Maybe an error in Bender&Trinkle's recent paper?

Post by shikui08 »

Yes, d(dC/dq H)/dt should be correct, as far as I can tell.
Erwin Coumans wrote:There could be a typo in equation 28 of the paper.

Can you replace the first term of k

Code: Select all

dC/dq dH/dt
by

Code: Select all

d( dC/dq H )/dt
and see if that helps?
Thanks!
Erwin
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