[ODE] Cylinder Functions

[Andrew Aye]

Cylinder vs Plane:

The existing test in the contribution is actually fairly solid.  Just need
to change the case where the angle between the plane and the cylinder axis
is less than 45 degrees, from its current depth computation to

depth = outDepth-dFabs(2.f*A2)

The greater than 45 degree case could do with a modification as well where
it would use equilateral points along the cylinder base rather than its
current method since, depending on the time step and ODE solution factors
the current system can cause undue rotations along the base rim.

Cylinder vs Sphere

There was a minor error in this test as well - I'll check to see what I
fixed

Rotation Matrix

I agree with some of the others here - I've never really run into a problem
with it before - its always been an orthonormal rotation matrix.  I would
check your source quaternions and conversion functions.  

 - Andrew Aye


-----Original Message-----
From: Nguyen Binh [mailto:ngbinh at glassegg.com]
Sent: Thursday, April 22, 2004 10:47 PM
To: ode
Subject: [ODE] Problem with Geom's rotation matrix


Hi ,

        In ODE, geom's rotation matrix is actually not "rotation
        matrix". It fails the attribute : R.Rt = I.
         http://mathworld.wolfram.com/RotationMatrix.html


        I think,there won't be much problem with that because ODE use
        quat to represent rotation internally. But it'll be very
        dangerous for any one always "assume" like me. :) .So it would
        be nice if this thing is stated directly in the docs.

        This thing makes me stuck in porting the cylinder-box from
        Croteam to ODE for days. Hic...

        About the progress of cylinder vs anything :
        I had almost finished the cylinder-box. (One of the hardest
        part ???) and fixed the framework for porting Croteam's code
        to ODE.

        To Russ and Adam : I will follow your suggestions in coding
        style and get rid of static stuff.

        To Alan : Is there cylider vs plane collider at your side? If
        not, I may write it my own cos plane is generally used in ODE
        as the ground. So it won't be good if our cylinder go through
        the ground.

    Happy coding!

    Nguyen Binh.

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