region stats. 2


point inside/outside a 3-d volume


locate cartesian axis centred on the point, inside the object if there are surface points on the object

with x < 0, x > 0, y < 0, etc.


for a specified point P and surface points A, inside if six points can be found, each with one of the 

following parameters


xa < xp

xa > xp

ya < yp

ya > yp

za < zp

za > zp



visible surfaces

surface point A is visible from observation point P if there are no points on the 

line A-P that are inside the object (see above).



