Problems with BOOLEAN

Hi there,

I´m using Blender 2.34 for about a week and try to model a simple shape of a special ship. Therefor I used a lengthend cube, subdivided it a few times and cut a deformed Cylinder out of one end of the cube. So far it worked perfectly.

Now I try to union another deformed cylinder with the other end of the cube. The cylinder has the same height and breadth of the cube and overlaps it to a half. Therefor I use the BOOLEAN - UNION function. The result was a union of the cube with only the upper surface of the cylinder.
If I lenghten the cylinder in a way that it overlaps the cube at the upper and lower boundary, the UNION will add this overlapping parts to the cube.

It must have something to do with the position “in front of the cube”. Objects smaller than hight and breadth will disappear with UNION. But the same objects have no problems with UNION at other positions at the cube.

I have no idea how to fix that problem exept starting a new drawing and would be grateful for a hint.


as a general hint, acoid blender’s booleans. They are outdated, slow, and buggy. There should be a new version of them implemented in the next release. Some people have already made some builds with good booleans in them, check out .

err, pictures, please. apart from that, stay away from booleans until there’s realyy really no other way. fully agree with samadam here.

Sorry, but I don’t understand exactly what you meant. There’s a pretty good Boolean script available here, though… You should check it out.