Question about collision for Hand model(bones)

[atamasan]

I have solved the problem by myself.
Thank you.

But I've got another question.
When I use <node3d>.collideSphere, the command usually work great. But when I change the scale of the node(especially, when I make the node small), collideSphere doesn't work.

For example,,,
ground=viz.add('shpere_ground3.ive')
ball=viz.add('white_ball.wrl')
ball.setScale(.1,.1,.1)
ball.setPosition(0,.5,0)
ball.collideSphere()

In this case, collision doesn't happen(ball falls down through ground). But if I change the scale of the ball(I make the ball bigger like [2,2,2]), collision can be seen.

What is the reason for this? Please give me some advice.

Thank you for reading.