[Pyode-user] embarrased that I can't figure this one out

[Robert R. <tif...@ho...>]

Help!
ok, I tried to boil down the pyode tutorial 3 to a very simple 38 line 
program just to test it.  There are only two bodies - a plane and a box.  
The print function at the bottom is the only output.   In theory, the box 
should fall and stop.

Interestingly, the callback seems to be called at the correct time (when z 
is just less than 5) but the box falls too far (say -20) and then bounces 
too high (back to near 46).  It's like the plane is made of very soft 
rubber.  Tutorial 3 does not display this behavior - the blocks fall and 
stop.

I have been playing with this code far too long - adjusting various 
parameters (bounce, etc) with no luck.  I must be missing something 
obvious...

Any help would be greatly appreciated.  Thanks!

Here is the code:

import ode

def near_callback(args, geom1, geom2):
	contacts = ode.collide(geom1, geom2)
	world, contactgroup = args
	for c in contacts:
		c.setBounce(0.2)
		c.setMu(5000)
		j = ode.ContactJoint(world, contactgroup, c)
		j.attach(geom1.getBody(), geom2.getBody())

contactgroup = ode.JointGroup()
world = ode.World()
world.setGravity( (0, 0, -9.81) )
world.setERP(0.8)
world.setCFM(1E-5)

space = ode.Space()

floor = ode.GeomPlane(space, (0,0,1), 0)

body = ode.Body(world)
M = ode.Mass()
M.setBox(10000, 10, 10, 10)
body.setMass(M)
geom = ode.GeomBox(space, (10, 10, 10))
geom.setBody(body)
body.setPosition((50, 50, 50))

fps = 80.0
dt = 1.0/fps

while True:
	pos = body.getPosition()
	print 'z =  ', pos
	space.collide((world, contactgroup), near_callback)
	world.step(dt)
	contactgroup.empty(