[Pyode-user] General question about ode

[Ricardo K. <ric...@gm...>]

Hi:

I am really new to this ode/pyode thing. I am trying to develop a simulatio=
n
using pyode. I finally made it (using several "borrowed example code" :-))
to have my objects get rendered on screen.

They are currently generated a bit above the ground, so when I rendered
them, they fall a little (inspired by the pyode tutorial2). I have created =
a
model that consists of two boxes that should be connected through a stick.
All three objects get correctly rendered, but they don't keep together (the=
y
just split apart as soon as they fall on the ground)

The code I am using to created those objects is:

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def create_box(world, space, density, lx, ly, lz):
"""Create a box body and its corresponding geom."""

# Create body
body =3D ode.Body(world)
M =3D ode.Mass()
M.setBox(density, lx, ly, lz)
body.setMass(M)

# Set parameters for drawing the body
body.shape =3D "box"
body.boxsize =3D (lx, ly, lz)

# Create a box geom for collision detection
geom =3D ode.GeomBox(space, lengths=3Dbody.boxsize)
geom.setBody(body)

return body

def drop_object():
"""Drop an object into the scene."""

global bodies

blockA =3D create_box(world, space, 1000, 1.0,1.0,1.0)
blockB =3D create_box(world, space, 1000, 1.0,1.0,1.0)
link =3D create_box(world, space, 1000, 1.0, 0.2, 0.2)
x, y, z =3D 0.0, 1.0, 0.0
blockA.setPosition( (x,y,z ))
link.setPosition((x+1,y,z))
blockB.setPosition((x+2,y,z))
m =3D mat4().rotation(0, (0,1,0))
blockA.setRotation(m.toList())
blockB.setRotation(m.toList())
link.setRotation(m.toList())

j1 =3D ode.HingeJoint(world)
j2 =3D ode.HingeJoint(world)
j1.attach(blockA, link)
j2.attach(blockB, link)
j1.setAnchor((0,0,0))
j2.setAnchor((1,0,0))
j1.setAxis((0,0,1))
j2.setAxis((0,0,1))
j1.setParam(ode.ParamFMax, ode.Infinity)
j1.setParam(ode.ParamVel, 0)
j2.setParam(ode.ParamFMax, ode.Infinity)
j2.setParam(ode.ParamVel, 0)

bodies.append(blockA)
bodies.append(blockB)
bodies.append(link)

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Maybe someone can help me to get this three objects remain connected all
time? Maybe I should have written to the ode mailing list, but since I am
writing code in python, I thought of this one.

With regards,

Ricardo Kirkner