WorldViz User Forum - Vive: trouble setting node as a child of the head

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- - Vive: trouble setting node as a child of the head (https://forum.worldviz.com/showthread.php?t=6112)

Vive: trouble setting node as a child of the head

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:

HTML Code:

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?

Try using the .setReferenceFrame command. Does this work for you?

Success with <node>.setReferenceFrame()

Thanks jeff! The following code worked...

HTML Code:

        import vizshape

        r = vizshape.addSphere(0.05, color = viz.RED)

        r.setReferenceFrame(viz.RF_VIEW)

        r.setPosition([0,0,1])

Problems continue. What's going on?

Sadly, my attempts to place a sphere along the gaze vector are still not behaving as expected. None of the parenting functions work, and viz.setRefrenceFrame is producing unpredictable results.

Here are two new attempts dropped into my vizconfig main function that uses the standard VIVE template. Neither work. Any advice from the peanut gallery?

HTML Code:



############# Attempt 1, what I thought would work...



        import vizshape

        

        IPD = viz.MainWindow.getIPD()



# It does seem that the right eye base is in the correct position and updates with head position

        rightEyeBase = vizshape.addSphere(0.05, color = viz.BLUE)

        rightEyeBase.setReferenceFrame(viz.RF_VIEW)

        rightEyeBase.setPosition([IPD/2,0,0])

        rightEyeBase.alpha(0.00)



link = viz.link(viz.MainView,rightEyeBase,viz.PRIORITY_SCENEGRAPH) # I tried with and without the link here

        link.setMask(viz.LINK_ORI)



        rightGazePoint = vizshape.addSphere(0.05, color = viz.YELLOW)

rightGazePoint.setReferenceFrame(rightEyeBase)

        

        smi = viz.add('smi_vive.dle')

        eyeTracker = smi.addEyeTracker()



        def updateGazeNode(vecLength = 3.0):

                

rDir = eyeTracker.getRightGazeDirection() 

rightGazePoint.setPosition(rDir[0]*vecLength,rDir[1]*vecLength,rDir[2]*vecLength)   

                

        vizact.onupdate(viz.PRIORITY_LAST_UPDATE,updateGazeNode)



###########







############# Attempt 2, based on the example provided by Worldviz (smiViveExample.py)

## Note that this doesn't accoutn for the right eye offset.



        import vizshape

        

        IPD = viz.MainWindow.getIPD()

        rightEyeBase = vizshape.addSphere(0.05, color = viz.BLUE)

        rightEyeBase.setReferenceFrame(viz.RF_VIEW)

        rightEyeBase.setPosition([IPD/2,0,0])

        rightEyeBase.alpha(0.00)



        rightGazePoint = vizshape.addSphere(0.05, color = viz.YELLOW)

        #rightGazePoint.setReferenceFrame(rightEyeBase)

        

        

        smi = viz.add('smi_vive.dle')

        eyeTracker = smi.addEyeTracker()



        def updateGazeNode(vecLength = 3.0):

                

                gazeMat = eyeTracker.getMatrix()

                gazeMat.postMult(viz.MainView.getMatrix())

                rightGazePoint.setMatrix(gazeMat)

                

        vizact.onupdate(viz.PRIORITY_LAST_UPDATE,updateGazeNode)

###########