WorldViz User Forum - Vizuniverse and grabhand

Hello Steve,

Here is an example showing how to create 2 GrabHand objects. You'll see from the GrabHand constructor, it has 2 dependencies:
-- a list of 3D nodes with physics shapes to grab
-- A hand object
---- Hand objects depend on having a InputSensor object that detects user input

The first half of the code sets up a local GrabHand controlled by the mouse. The second half is a code outline for setting up a remotely controlled hand.

Code:

import viz

viz.go()

viz.phys.enable() #must enable physics for grab to work

viz.add('lab.osgb')

viz.MainView.setPosition([0, 1.8, -2])



#objects to grab

grabObjects = []

for i in range(10):

        box = viz.add('box.wrl', pos=[i/2.0, 1.7, i])

        box.collideBox() #must have physics shape to grab

        box.disable(viz.DYNAMICS) #no need for gravity

        box.grabbed = 0

        grabObjects.append(box)



#LOCAL HAND

#hand object that supplies user input: grabbing or not

import hand

mouseButtonControl = hand.MultiInputSensor(pinchButtons=[viz.MOUSEBUTTON_LEFT,viz.MOUSEBUTTON_RIGHT], fistButtons=[viz.MOUSEBUTTON_MIDDLE])

localHand = hand.add(mouseButtonControl)



#move hand position

import vizuniverse

handTracker = vizuniverse.VUTrackerMouse2D() #just a 3D node to supply position and orientation for hand.

viz.link(handTracker, localHand)



import GrabHand

GrabHand.GrabHand(grabObjects, localHand, springs=False) #springs only work on dynamics enabled physics shapes





#TODO FOR REMOTE HAND CONTROLLED VIA NETWORK

# Create local hand input object:

networkHandInput = hand.MultiInputSensor()

def onStartGrabFromNetworkEvent(): #called via network event callback, say viz.NETWORK_EVENT

        networkHandInput.startPinch()

def onEndGrabFromNetworkEvent(): #called via network event callback, say viz.NETWORK_EVENT

        networkHandInput.endPinch()

        

#create hand object

remoteHand = hand.add(networkHandInput)



# Get 3D position of remote hand

vrpn = viz.add('vrpn7.dle')

remoteHandTracker = vrpn.addTracker('Tracker0@localhost', 0)

viz.link(remoteHandTracker, remoteHand)



#create grabhand object

import GrabHand

GrabHand.GrabHand(grabObjects, remoteHand, springs=False) #springs only work on dynamics enabled physics shapes

WorldViz is still working to officially fold-in the two modules you mentioned so docs/examples are still sparse. Happy to provide more explanation if needed.

On the networking architecture side, I think your project is simple enough to just use a 'peer to peer' design where all clients hold the same representation of the world. The Tutorial:Networking in the Vizard help is an example of this. When world behavior is not deterministic, like with dynamic physics, then you should setup a client/server architecture. The viznet library in the install will help with this and I attached a zip with examples.