In article <slr### [at] xmissionxmissioncom>, Peter McCombs wrote:
>Where "vec" is my perpendicular vector that I want to find the point on, and 
>"the_distance" is an arbitrary distance along that vector?  What does "position"
> represent on the vector? 


I think I can answer my own question on this now, thanks to the helpful
discussions in this thread:


A vector represents a direction in relation to the origin <0,0,0>, so in order
to find a point on a vector, I need to make sure the vector is translated
relative the object I am referencing with it. In my case, I want a point on a
vector that is perpendicular to the direction of my spline object.

I first normalize my perpendicular vector to ensure that its magnitude is 1
(a unit vector). This is so that I can specify points on the vector in terms
of units rather than factors of vector magnitude (right?).  This is
accomplished like so:

#declare vecPoint = vnormalize(vec) * distance;

Now, since this will get me a point relative to the origin, I should also 
add a translation into the equation:

#declare vecPoint = vnormalize(vec) * distance + aSpline(currentPoint);

This ought to give me a point relative to aSpline(currentPoint) at a distance 
of distance.

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