Ribid body definition

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ypapelis
Posts: 9
Joined: Mon Nov 08, 2010 8:44 am

Ribid body definition

Post by ypapelis »

I am using the wizard in Arena to define rigid bodies for tracking. The problem I am having, I need accuracy on the definition of the origin and orientation of the rigid body. The interactive GUI manipulation is pretty hard to use and I have found no easy way to edit the definition of the rigid body relative to the markers. What can I do to address that?
Birch
Posts: 1139
Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: Ribid body definition

Post by Birch »

You can try adding an extra marker (it does not have to be part of the rigid body itself) and using that marker to set the origin. On the Set Origin page of the wizard just click on the desired marker and press the set origin button.

That should provide accurate control over rigid body origin.
ypapelis
Posts: 9
Joined: Mon Nov 08, 2010 8:44 am

Re: Ribid body definition

Post by ypapelis »

Well that sets the origin, but I still have to define the orientation. It would be nice to have an ability to line up any of the axis by using markers. All in all though, the best would be to have the ability to edit the rigid body directly. Is that possible?
chiacchio
Posts: 4
Joined: Fri Jun 10, 2011 12:37 am

Re: Ribid body definition

Post by chiacchio »

I have the same problem too. Did you find any solution/workaround?
NaturalPoint - Mike
Posts: 1896
Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

Re: Ribid body definition

Post by NaturalPoint - Mike »

In the rigid body wizard, on the origin definition page, you can use the tools above the visualization to move three arrows to change the orientation. Blue points to positive x, green points to positive y, red points to positive z.
ypapelis
Posts: 9
Joined: Mon Nov 08, 2010 8:44 am

Re: Ribid body definition

Post by ypapelis »

Mike,

Thanks for the response, but that still does not _accurately_ solve the problem. It is like in a drafting package or visual model creation package, you never depend on a person clicking on the screen in order to match two vertices; you provide a snap function or grid or some other facility to ensure that vertices that should be identical indeed are identical. The problem here is the same, I want to line up a body perfectly relative to the markers, not 'click' and hope.

I still wonder if it would be that hard to expose a transformation that is applied to each body.

Or another alternative may be to add a button that allows you to establish the current position of the rigid body as the origin (both position and rotation) and have the system calculate the transformation. This functionality is there now in the orientation, maybe an extra button to provide the same for the position?
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