> here the 3dm "bugs" http://www.zbrush.fr/phpBB2//download.php?id=1055
> architecture windows persistant (the rectangular block for closed the window by Boolean
> union) a rectangle persist!

Hi Pilou, I see now. But this is not exactly an error, it is valid to have objects that are set up like this.

Here is an example:

If I have 2 surfaces, one with a hole in it, and I have another surface that fits within the hole, I can move them together and then use "join", to get this result:

This is just two surfaces joined together - two planes can be joined together at shared edges just like any other surfaces can be joined together.

Now, if you wish to simplify this, here is what you would do - select the inner face, and do a delete, removing it and leaving a hole. Now select all the edges of the hole, and do another delete. This will remove the trimming boundary that defines the hole.

Remember that post yesterday where I was showing how trimmed surfaces work? Well, that was showing an outside trim boundary that trimmed away the outside of the surface. There can also be interior trim boundaries, which create holes inside a surface.


It would be nice if booleans always optimized planar shapes so that they would be single planes instead of creating joined pieces like this. But it will not be easy to fix this to happen in all cases for a while.

I'd recommend that when you want to remove a piece, you should use usually use delete to do it more often, not boolean union.

So for instance, to remove a window, don't create a box - instead select the side pieces of the window and delete them. Then select the open edges of the window and delete them too, removing the hole - now the window is erased and the original surface is restored in that area. You can only delete edges if they are not attached to something else, so that's why you delete the side pieces of the window in a first step.

So using this method you can repair any of those pieces that you wish to remove. Let me know if this is not clear.

- Michael