In VBA programing, I encountered the solid subtract problem, and was suggested to post out at here. I attached the dgn file and example photos again:
Subtract_Problem.zip
Link to Original Post (Microstation Programming Forum)
Assuming the goal is to subtract the green slab from the blue extrusion (I changed the colors for clarity), modify the green slab so that it clearly extends past the blue extrusion instead of clipping through it like it's doing now. Look at the area identified by the red circle in View 1 below, View 2 is zoomed in view.
HTH
-B
As reminded by Jon Summers from the programming forum, I re-upload the dwg files at this forum and thanks for the Brien Bastings' kindly analysis.
SaveAsDWG.zip
The solid in the DWG is pretty much garbage; it has a small void and essentially a zero-thickness face.
The boolean subtraction failing in MicroStation is possibly to prevent the both of these anomalies, but lets also apply some reasonable, real-world logic to the discussion. Would you expect to see a piece of steel like that from a fabricator? Of course not, so you should follow Brien's first piece of advice to adjust the cutting-solid (even with a sacrificial duplicate), in order to create the correct clean cut.
Mm.... I created another example, and that is to show Microstation cannot create simple solids with self-intersection. You cannot subtract the box with triangle. So it falls in the argument: Is this shape possible?
Subtract_Problem2.zip
Additional notes:
Subtract solid in V8i but Difference Feature in CE
clever_anthony said:So it falls in the argument: Is this shape possible?
If the boolean imprint is a single line (your case above where triangle intersects middle of box face) or a single point (replace triangle with sphere coincident with face of box) it is not possible to subtract them.
Answer Verified By: clever_anthony