From: Antlab 16 Feb 2008  (1 of 6)
 Hi all. I am playing with the trial version of MoI (Michael, the new version is still valid after three days), and I have a question about booleans. The case is simple. I draw a rectangle, then extrude (a sort of "room"). Then I put a plane on one face, as a "door". Now, if I subtract the door from the room, I don't obtain a "hole". Instead, if I previously deleted the upper face of the room, the boolean operation with the door works as I expected. Maybe I am missing something fundamental about booleans operations in this situation? Ciao Antonino Image Attachments:

 From: Michael Gibson 16 Feb 2008  (2 of 6)
 1390.2 In reply to 1390.1 Hi Antonino - yes I see that is a bit odd. The problem here is that if you have a solid base object, the booleans will tend to expect either a solid cutting object, or for a surface one that fully divides the solid into 2 smaller solids. In a sense the booleans will try to generate a solid as the result if the original object was a solid. If you want to cut out a piece of a solid like you are showing there, you should use the Edit/Trim tool for that type of cut instead. Trim does not attempt to keep solids as solids and will let you cut up the outside skin of a solid any way you want. It may be easier for you to use Edit/Separate on the solid to break it into 6 individual surfaces first, and then work on those surfaces separately. You can then later on use Edit/Join to glue them back together into a connected object after you are done editing the pieces. Also instead of using a plane as the cutting object, I'd recommend using a rectangle curve as the cutter instead. Coincident surfaces tends to be a more difficult calculation and also it can be more difficult to select by clicking when there are 2 coincident surfaces. Curves are much easier to select, so it is more of a recommended workflow to use a curve as the cutting object in this case. - Michael

 From: Frenchy Pilou (PILOU) 16 Feb 2008  (3 of 6)
 1390.3 In reply to 1390.1 ??? No result is the same : roof or not roof :) Select as on the image ! The door will made a hole :) EDITED: 16 Feb 2008 by PILOU Image Attachments: