Hi Luc,
There seems nothing to be obviously wrong with your script that should make the system crash, other than the indentation after the timer, which was probably stripped out by copy/paste
PHP Code:
def ontimer(num):
data = ppt.get()
#this one will make the model slowly transform
#ball.size(data[0],data[1],data[2])
#this one makes the model quickly scale
ball.scale(data[0],data[1],data[2])
pos = ppt3.get()
ball.lookat(pos,0,viz.ABSOLUTE_WORLD)
Other than that, the ball you are referring to in line 16 was not defined previously, so you will need to uncomment
ball = viz.add('white_ball.wrl')
in line 7.
When running your script here with a PPT connected sending the position data of 3 points, the script runs fine and stable.
Is it possible that there are problems with Vizard due to your graphics card / computer configuration? Please make sure you use the latest graphics card drivers, update if necessary.
Also check if there are other USB devices connected to the computer that could cause problems.