Collision of an avatar with a quad

[Frank Verberne]

Hi Farshizzo,

Could you post the code for dynamic collision with live characters? The rest of the task is done now, and I have been struggling with the code to create something like you said (collision shapes for each major limb) but haven't been succesfull. I also tried to put avatar.collidemesh() into a timer, but that was too demanding (regarding the CPU I guess).

Thanks in advance!

[farshizzo]

Do you need dynamics on the collision, or do you just need to know when the avatar touches an object?

[Frank Verberne]

I don't really know what the difference is, but what my task is that a participant controlling an avatar has to touch several quads. Each quad has a bounding box around it, and every time the avatar touches the quad (i.e. enters the bounding box) the program checks if the number is the lowest of the 6 quads. If it is, the quad will turn green, otherwise the quad wil become red for a few seconds and then restore itself. This task is done multiple times.

So I think that I only need to know when the avatar (no matter which part of the avatar) touches the quads. Hope that clarifies the situation.

[farshizzo]

Here is a sample script that shows how to setup collisions with the right hand of the avatar. Adding support for other body parts should not be too difficult.

import viz
viz.go()

#Enable physics
viz.phys.enable()

#Create ground plane
ground = viz.add('tut_ground.wrl')
ground.collidePlane()

#Create static box in front of avatar
box = viz.add('box.wrl',scale=[2,2,2],pos=(0,1,1.7))
box.collideBox()
box.disable(viz.DYNAMICS)

#Create avatar that doesn't like big boxes
avatar = viz.add('vcc_female.cfg')
avatar.state(6)

#Create a collision box and link it to right hand of avatar
rHandBox = viz.add('box.wrl',scale=[0.1,0.1,0.1])
rHandBox.collideBox()
rHandBox.disable(viz.DYNAMICS)
rHandBox.enable(viz.COLLIDE_NOTIFY)
rHandLink = viz.link( avatar.getBone('Bip01 R Hand') , rHandBox )
rHandLink.preTrans([0.05,-0.05,0])

#Comment this line out if you want to see the collision box around the hand
rHandBox.disable(viz.RENDERING)

#List of colors to cycle through
colors = viz.cycle([viz.WHITE,viz.BLUE,viz.RED])

#Change color of box when avatar hits it
def onCollideBegin(e):
	if e.obj1 == rHandBox:
		if e.obj2 == box:
			box.color(colors.next())
viz.callback(viz.COLLIDE_BEGIN_EVENT,onCollideBegin)

#Setup camera navigation
import vizcam
vizcam.PivotNavigate(center=[0,1,0],distance=5)

[Frank Verberne]

Farshizzo: thank you very much for the sample code! It works perfectly. I tried to do the same while using the live characters plugin and for some reason it didn't work then. I guess linking the box directly to the same tracker that also animated the avatar (so the same tracker was linked to a bone using MotionBuilder and to a box) could have been the problem. I will test this solution on monday and I will let you know if I still encounter some problems or if my problems are solved (during the weekends I don't have access to the live characters plugin).

[Frank Verberne]

Hi Farshizzo,

Your solution also worked in the lab! So thanks for your solution!

Yours, Frank