A question about HingeConstraint

Baune
Posts: 20
Joined: Tue May 26, 2009 2:36 am

A question about HingeConstraint

Post by Baune »

Hello

I see that the hingeconstraint has two pivot points and two axes which puzzles me.
Shouldnt it just have one of each ? what's the second one used for ?

Thanks

Baune
NickoPen
Posts: 4
Joined: Fri Jun 19, 2009 1:43 am

Re: A question about HingeConstraint

Post by NickoPen »

I'm surprised nobody replied to you sooner - if you haven't worked it out: you have two sets for the location of the axis in each body's own local frame and ditto for the orientation of the axis.

It's an annoying representation as it's a redundant specification, and if you mis-specify (for example have the axis out by 180 degrees) then the bodies rotate and move about until they reach a valid solution. I believe that whatever allows for this motion is what causes the articulated body simulation in bullet to be sub-par.