Vive: trouble setting node as a child of the head

[performlabrit]

Hello folks,

I'm trying to do a routine operation with the vive, and am having trouble. I would like to set a node (a vizshape sphere) in front of the head eye. One approach is to child the node to the mainview, or the head tracker. However, neither approach seems to work!

For example, if you use the standard vizconnect VIVE config and add the following code to main:

import vizshape
ht = vizconnect.getRawTracker('head_tracker')
r = vizshape.addSphere(0.05, color = viz.RED)
r.setParent(ht)
r.setPosition([0,0,1]) # Doesn't work for any forward direction (e.g. [1,0,0])

It also doesn't work if I child it to the mainview.
Am I missing something?

Also, in the code above, note that the assumption is that the head is facing down Z in the model's local coordinate system. I'm not sure that this assumption is true (although, no other directions work either). What direction is "forward" and what direction "up" for the Vive?