Re: [Pyode-user] Newb Problem with tut2!

[Chris B. <chr...@gm...>]

On 07/11/05, Matthias <Sta...@gm...> wrote:

>                 kx, ky, kz =3D kugel.getPosition()
>                 print kx, ky, kz
>                 pygame.draw.line(srf, (0,0,0), coord(2, 3.8), coord(kx, k=
y), 3)
>
>                 pygame.draw.rect(srf, (0,100,50), (coord(kx, ky), coord(k=
x + 0.1, ky -
> 0.1)), 0)

from http://www.pygame.org/docs/ref/rect.html#pygame.Rect we find the
definition of Rect:
pygame.Rect((left, top), (width, height)): return Rect

But you used absolute coordinates instead of (width,height) - your
rectangle size is shrinking as kx and ky approach the origin!

This works better:
pygame.draw.rect(srf, (0,100,50), (coord(kx, ky), coord(0.1, 0.1)), 0)

Now your next problem is that the joint with the ode.environment
doesn't seem to be working. The body is always moving towards the
origin. Even if you set the gravity to (0,0,0) it does this. This
indicates a prolem with the joint - since the only force in your
simulation is generated by ode trying to correct the errors in this
joint. The problem is command order, you need to attach the joint
before setting the anchor:

       bj.attach(kugel, ode.environment)
       bj.setAnchor( (2, 3.8, 0) )

That should fix your problems.

Chris