DESCRIPTION:

Construct a convex hull around a series of 2D outlines.
This is done be searching for planes perpendicular to the given
axis that contain voxels of color "bordercol". Whenever such a
plane is found, all bordercol voxels in that plane are
connected to the corresponding voxels in the next plane in
an angular fashion(see below).
The center for determining the angle is usually estimated by
calculating the center of gravity.
However it can be given by colorizing additional voxels in the
plane in color sp (star point).
Angle is usually identified globally, but you can give up to
3 points on the border by colorizing them as p1, p2, p3 that will
influence how voxels are matched.
If only p1 is given, those points will be matched up by turning
the angular systems. If points for p1 and p2 are given, the
systems are distorted in a way that make both points match.
Using a third point (p3) will allow to change the direction of
rotation as well.
Corresponding points (those that are within tol degrees) will
be connected by lines which recolor the voxels on the lines
from remarkfrom to to.