3D intersection and division in RTOPO Software

RTOPO (http://rcad.eu/rtopo/) can intersect and divide two triangulations (or two sets of 3dmesh and 3dface entities) or a triangulation by a horizontal plane.
3DInt command intersects two sets of 3DFace entities.
If the 3DINt_type variable is 1, 3DInt will generate in the "3DINT" layer only 3DPOLY (LINE) entities representing the intersection. They will be colored from 1 to 1, beginning with the color 1. The joints in 3DPOLY of the intersection segments will be made according to CONcat_prec variable.
If the 3DINt_type variable is 2, will be made only the division and concatenation (the joint) of 3DFace entities, along the intersection. A quadrilateral 3DFace will be decomposed into two triangular 3DFace. A triangular 3DFace can be divided only in two pieces, along the intersection of two of its sides! If a triangular 3DFace is intersected several times, the results will be inaccurate! After division, zones will be generated, by concatenation of 3DFace which will receive the same color. A zone is formed by 3DFace entities that are placed on the same side of an 3DPOLY of intersection and in contact with common sides (respecting CONcat_prec accuracy).
The zones will be colored from 1 to 1, beginning with the color 1. If it results bad zones, divide first the large 3DFace entity with DIVIde_3dface command and/or increase the value of CONcat_prec. The 3DFace entities located in zones will be in their original layers. You can select a zone using the "COlor" option (see Modify).
If the 3DINt_type variable is 3, will be generated 3DPOLY of intersection and the division and concatenation of 3DFace entities.