yade-dev team mailing list archive

[Anton Gladky <gladky.anton@xxxxxxxxx>]

Ok, thanks, Bruno, I will have a look.

Anton




On Fri, Jan 14, 2011 at 10:08 AM, Bruno Chareyre
<bruno.chareyre@xxxxxxxxxxx> wrote:
> Hi,
>
> After a quick look at rotation engine, one suggestion.
> Better precision would be obtained by defining "secant" velocity instead
> of "tangent".
> (1) Currently ("tangent") : vel = spin.cross(l), then vel*dt is only
> approximating the exact circular trajectory (if vel*dt is large, then
> the object will go away from rotation axis.
> (2) It could be something like ("secant") : vel =
> (rotatedPos-currentPos)/dt =  (q*(pos-axisPt)-pos)/dt
> Then the integration would be exact and pos-axisPt length would be constant.
>
> q is computed at KinematicEngines.cpp:90 but not used currently.
>
> Bruno
>
>
> _______________________________________________
> Mailing list: https://launchpad.net/~yade-dev
> Post to     : yade-dev@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~yade-dev
> More help   : https://help.launchpad.net/ListHelp
>