Problem with Boolean

Hello guys, It's been a long time I don't post in the forum

I have a problem with Gmax trying to cut a box using Boolean, and the Cut isn't very accurate (according to the object I selected as the Operand B), check the original objects, the blue is the one I selected as Operand B

I used the "Move" (between Reference, Move, Copy and Instance mode) in "Pick Boolean" section, then, used Cut -> Refine in "Operation", and I got this

I'm using the FS2004 Gmax SDK

I need your help, please


Resource contributor
I think both object must have the edges that overhang from each other. The vertex of both objects cannot be on the same plane. If you clone the roof and expand it in the axis -y by that picture, it might help.


does Operend B have any polys, verts, edges that intersect with others on that model?

If so, this tends to make the GMax Boolean tool go crazy and do this, where it trys to cut around the EDGES, and then meets another edge which is intersecting it and then closes this cut.

Try remake Operend B so it is one object, connected together, not a single tube pasted over and over again, also make sure it COVERS the roof of Operand A, use the extrude tool if you need to or scale Operand B on the Z axis to make it "higher".
Hello again, I tried expanding the roof (Operand B) using the "Select and Uniform Scale" mode, and "Select and Non-Uniform Scale" in the axis Y and Z, and the result is the same

I uploaded the gmax file with the objects

Edit: I made the roof using a lot of cylinders, 19 cylinders in total, I cuted the first cylinder in half and removing the polygons in the center, cloned it 18 times and attached them to the first one


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Resource contributor
Hello Juan, what are you hoping to do with the boolean? A boolean is of no use unless operands A and B overlap and your roof just sits on top of the building with no overlap between the two.

If you want to cut the roof line to match the building's outline you'd be better off with the Slice modifier or the Slice Plane. FYI you should make sure you're working in Editable Poly, but your objects are already that!

I've modified your file as I describe, it's attached below.

If you are using Boolean for anything, I'd strongly recommend using Reference and Cut and Refine settings at least until you know what you're doing with the operation.

Hope this helps.


I maked again the roof (operand B) and the building, applied Boolean and it worked perfectly

Thank you very much :cool: