Rotate object around mainView?
 

I'm having a bit of trouble here, with what I think is a simple problem.

I have linked the mainView to a vizShape object hmdBox. This box reflects head position returned by a motion capture system. I move around the viewpoint indirectly, by moving around hmdBox. Now, I want to draw another vizShape object that is attached to HMD box, that I can freely rotate around the mainView or HMDbox using .setEuler, preEuler, or a similar function.

The goal is to define position in polar coordinates in a head-based reference frame, so that when the head changes orientation the object stays in a fixed position in the subject's field of view. I imagine the steps are something like this: set the distance of the object from the mainView/hmdBox using preTrans(), and then define an angular offset from the straight ahead vector (preEuler?).

It is important to maintain the parameters of degrees of angular offset and distance.

I should say that the only behavior I'm able to get is this:
The object rotates in its own reference frame (not relative to the parent)
or
the object rotates in another reference frame (i assume it's the world-based reference frame)

Should I not be linking, but be setting position etc rel-parent? Other strategies?

My thanks in advance,
- gD

TO answer my own question:

The rotation didn't seem to work, so I've achieved my goal by:

- Not linking, but creating vizShapes that are children of the hmdBox node (that is linked to the mainview)

- doing my own trig to calculate position of the object based on offset angle and distance from the mainview.

- Moving the objects with setPosition

It's not the first solution one might try, but it works.

Have you tried using postEuler to roate the linked child relative to the HMD? preEuler would rotate it relative to the child itself as you reported.

Sure did. It was rotating in an unknown frame of reference - perhaps the world-base frame of ref, but it's unclear.