Try:
Code:
Prototype int ac_object_find_bound(ACObject *ob, Point3 *max, Point3 *min); // returns 0 if no geometry (therefore bb is invalid)
then something like this:
Code:
Prototype void find_box_size(Point3 *max, Point3 *min, Point3 *out)
{
Point3 diff = *max;
SUBTRACTPOINTS(min, &diff);
ABSPOINT(&diff);
*out = diff;
}