Greg M. Johnson wrote:

> I have two splines where
>   vlength(Spline_1(Val)-Spline_2(Val)= W
> for every value of Val.
> 
> Now I have a box with one dimenstion W and a given L (H is irrelevant).
> 
> Q: How do I get the four corners of W&L to be aligned as closely as possible
> to the two curves?


First, position the center of the box :
#local center = (Spline_1(Val)+Spline_2(Val))/2;
Next find the orientation of the box:
#local orienta = Spline_1(Val) - center; /* length of orienta is W/2 */

Then use the Reorient_Trans(x,orienta) macro from transforms.inc
(you might want to replace x with either y or z, according to your box)
just like that:

box { -W/2,W/2 /* any texture&interior goes here */
Reorient_Trans(x,orienta)
translate center }



> 
> The application is a railroad with not-so-flat rails (ala'
> http://news.povray.org/povray.binaries.images/27516/).   I can think of a
> very, very hairy algorithm that involves millions of rotations until I get
> it best aligned in three axes, but I'm wondering if there were a more simple
> trick out there....
> 
> 
>

Post a reply to this message