boolean modifier bug

i used the boolean modifier but for my bad luck i get this bug

why does this happens?

did your boolean object consist of a single stepped cylinder, or lots of separate cylinders? It looks like the modifier has left a bit of geometry in between each step.

What does the wireframe look like?

it consist a single stepped cylinder

here is the wireframe

Can you please upload the scene file so we can have a look?

And btw, not everything that does not work out as expected is a “bug”, it’s just that automatic solutions can only do so much. In a polygonal modeler booleans can in most cases only be an intermediate step, as they inevitably create horrible geometry that will need massive manual cleanup. And the more complex the boolean objects are, the higher the probability that the whole boolean operation might fail or create artefacts - especially if the boolean objects are not cleanly modeled themselves (n-gons, loose parts, internal faces etc.).

example.blend (723 KB)
i have attach the file so you can take a look.

the modifier is already at the square model, you just click at apply to apply the modifier.
(do operation “difference”)

One of your object has an insane amount of internal faces, that’s always going to be a problem for the booleans.
Fix the object like that and the booleans will work good :

Nice you fixed it but how you did it?
I need to know because this problem happens to me a lot of times.

Can you explain me step by step?

and btw how i can remove the internal faces?

To fix, i simply didn’t removed the internal faces, i redid your object like that :

  • remake only the side of the object

  • switch to top view

  • press the Spin button

  • press F6 (or look in the operator panel, bottom of the toolshelf to the left of the 3DView) and set it up like that ( 64 because your object had circles made of 64 pixels) :

  • Select all and press W -> Remove Doubles (because 360 degree spin will double the vertices at some point)

  • Press CTRL+N to recalculate the normals (after a W -> Remove Doubles it’s always a good idea to do so)

  • select the top loop and press F then do the same at the bottom to close them with a ngon face.

And that’s all, object is ready for booleans.

Note : i saw that your object didn’t had rotation or/and scale applied (it happens when you rotate or scale an object in Object Mode) , rotation/scale unapplied in Object Mode can lead into problems with some Edit Mode tools, so in Object Mode be sure to select an object and press CTRL+A -> Rotation&Scale

Thanks Sanctuary!