> Sure, not much difference if you store two vectors or all three. I also
> stored the information in an external file of course, being the only way
to
> transfer data from frame to frame. :) Btw. I think it's a good idea to
once
> in a while (or just in every frame to make it simpler) force the three
> vectors to be perpendicular to each other to prevent accumulated precision
> errors to slowly skew the matrix.

Yeah, those are things I still need to implement. I just wanted to show
that the initial stuff was working properly. :-)

> So if the big sphere is not just a ball but also a vehicle, then you'd
need
> to store vectors for the vehicle's alignment as well as for the ball's,
the
> difference being that the vehicle keeps having an up-vector that
corresponds
> to the up-vector of the ground, and a forward-vector that is the direction
> the vehicle moves in (typically). This, along with the position, which is
> the same as for the ball, could be used to get the transformation for the
> vehicle's upper hemisphere etc., which stays fixed regardless of the
ball's
> rotation. From this, it should be no problem to calculate global points
that
> are in a fixed relative position to the vehicle.

Well, as for fixed relative's position, I simply thought I'd place the
machine
on top of the sphere. What I'm after is actually a way to calculate the
rotation-
matrix for small spheres which always stay on a fixed location of the
machine.
So when the big sphere moves forward, a smaller sphere touching it would
have to roll backward appropriately. Depending on position and angle to the
actual rotation-axis, a small sphere has to turn more or less.

> Your project sound very interesting. I'm looking forward to see the
> progress. :)

Good to know, though I'm not quite sure how fast I will get along with
things.
Even with spare time I've got some work to do, especially considering that
lots of my colleagues are away over the holidays and the remaining staff has
to work double because our bosses didn't rememember to hire new staff
early enough... In the end, that's just more money for me though. :-)

Regards,
Tim

-- 
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>

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