Optitrack with V120Duo questions

[stefano.mottura]

Dear all,
I am a newbie with a V120Duo system (thus, 1 couple of cameras) I have some questions about the Tracking Tools application, I have searched in the forum and in the documentation but I am not sure about the info that I have found:
1) With Tracking Tools SDK, the rotations rx, ry, rz of the rigid body (obtained with SDK function "TT_TrackableLocation") are Euler angles with the sequence X, Y, Z, is it right?
2) What is the role of the "Set Ground" plane in the "Coordinate System Tools" in the Optitrack-Tracking Tools application? There is a specific way of using it? Is it mandatory?
3) For setting the pivot of a rigid body as located in the center of a specific marker: the "Trackable Pivot Point Translation" panel in the Optitrack-Tracking Tools is the only way or what?
4) In the "Trackables" panel of the Optitrack-Tracking Tools application I saw a "3DS Model" field. What is it?

Thank you very much for your attention

Best Regards

Stefano

[NaturalPoint - Mike]

The Eulers are applied in the following order: Y, Z, X

Set ground plane allows you to use a ground plane (found here) to define the global coordinate plane (origin, axes). It is not mandatory, however it does assist in defining your 3d tracking space.

"Trackable Pivot Point Translation" would be one way of setting the centroid location. Additionally, you can edit the Trackable properties and adjust marker locations with respect to the centroid manually.

3DS Model allows you to apply a .3DS file from 3d Studio Max to render an object on the screen in place of the trackable.

[stefano.mottura]

Mike, thank you for the answers.
I can load a 3DS model now, my model was originally out of scale and I was unable to see it...!
I have another question (always for V120 DUO system):
*without* ground plane set, is it possible to define a rigid body and obtain its ORIENTATION in the reference system of the cameras? I ask this since I have noticed that a just-created rigid body has an orientation of (0, 0, 0). (As alternative, I know that, with the ground plane set, the rigidy bodies are related to it).
Thank you very much
Best Regards
Stefano

[NaturalPoint - Mike]

The orientation of the rigid body will always be 0,0,0 at definition regardless of the status of your ground plane. Tracking Tools has no way of telling where your markers are in relation to the orientation you want the rigid body to use, so it defaults to the position it was in when you clicked "create".

Setting the ground plane makes this easier to understand because there's a clear coordinate plane in place you can use to decide rotation when placing the body before generating it.

[stefano.mottura]

Ok Mark, thank you!
Regards
Stefano

[stefano.mottura]

I mean Mike...!