> #local rx = degrees(acos(vdot(d, <0, d.y, d.z>)));
> #local ry = degrees(acos(vdot(d, <d.x, 0, d.z>)));
> #local rz = degrees(acos(vdot(d, <d.x, d.y, 0>)));

I'm not sure exactly what you were trying to do here (I'm sure there's logic
to it but I'm just not following it), but chances are after you do the
rotate rx*x (if that's what you're doing), the ry and rz rotations are no
longer useful for the object's new position.

Another thing to consider is that only two rotations should be needed to
make an object point in a certain direction. (This is because a direction
can be represented as a point on the surface of the unit sphere, and the
surface of a sphere is 2 dimensional.) For instance, if an object is
pointing in the positive x direction, a rotation between -90 and +90 degrees
around the z axis, followed by a rotation between -180 and +180 degrees
around the y axis is enough to orient the object in any direction. (A
rotation around the x axis could be done before either of these to have
control over how the object is rotated around the axis it's going to point
in.)

In any case, there's no point (besides educational reasons) to go through
all this work, since you can just use the Reorient_Trans macro in
transforms.inc to do what you want. (The macro doesn't use rotations, it
instead creates a matrix transformation; this is a more straightforward way
of approaching the problem if you understand the math.)

 - Slime
 [ http://www.slimeland.com/ ]

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