Editing Creating and editing arbn primitives

= Creating and editing arbn primitives =

An '''arbn''' primitive is an arbitrary complex polyhedron bounded by N three-dimensional planes.
 
Such solids are constructed by specifying N sets of plane coefficients and distances, which collectively define the space ~outside~ of the solid.  The coefficients define a vector whose normal is a plane parallel to the face of the solid. The surface of the solid is at the specified distance along this vector.  

The distances may be negative and are used when a face lies on the opposite side of the origin as the tip of its vector.  An example is if the left side of a box lies on the positive X axis.  In this case, because the left side is being defined, the vector points left (coefficients -1 0 0), but since the point is on the positive X axis its distance is opposite its vector and therefore negative.

;Handled by: make in create
;Arguments
:Number of planes
:xyz direction vector and distance for each plane

;Example
:in arbn.s arbn 8  1 0 1 1  -1 0 0 1  0 1 0 1  0 -1 0 1  0 0 1 1  0 0 -1 1  0.5 0.5 0.5 1  -0.5 -0.5 -0.5 1

;Example with negative distance
:in arbn2.s arbn 6  1 0 0 100  -1 0 0 -10  0 1 0 200  0 -1 0 -10  0 0 -1 0  0 0 1 1.5
:...is equivalent to...
:in rpp.s rpp 10 100 10 200 0 1.5