View Full Version : Boolean leaving gaps!!

01-23-2012, 06:59 PM
Hi Folks.

I have a model which I am trying to boolen subtract out little bits here and there to create detail. The problem is that the boolean is not clean. The newly cut geometre is not perfectly connected to the existing model polygons and there are gaps between the newly cut edge.

How do I stop this from happening? What's the key to a successful boolean?

01-23-2012, 07:06 PM
CTRL+U, Unweld

CTRL+T, Triple (Both FG and BG)


Select all polygons. Merge polygons.

Merge Points

Report :D

01-24-2012, 12:12 PM
Thanks, Probiner. The model it on my other computer so I'll test this tonight.

01-24-2012, 01:15 PM
IIrc I've had similar issues when some polys were flipped. Might be worth checking if the model has it's polygons aligned

01-24-2012, 05:35 PM
Thanks for the help, guys, but it didn't seem to pan out for me.

I followed the instructions above and it seemed to go well until I zoomed in for a close up. The boolean didn't actually create a cut but instead the cut ended up like stenciled geometre on the model?!?

I checked the polygons as best as I could and as best I can tell and the polygons are facing the correct way.

01-25-2012, 02:41 AM
Well... share the model or part of it?

Good Luck

01-25-2012, 08:03 AM
Perhaps the model is too small? (as in nanometers or smaller)

01-25-2012, 10:03 AM
tend to think of polygons as real when in fact they are interpolated from the points at their corners and the area between those points can get a little vague in terms of precision from the Boolean tools point of view and one poly cutting another equals twice the problem, Booleans rarely end up neat and always need cleaning up and merging, if it didn't end up cutting all the way through either the background layer is not penetrating the foreground sufficiently ore some or one of the poly's is so non planer the program cannot figure out where to cut, or even that something was not properly welded

01-25-2012, 05:41 PM
Thanks for the feedback, folks. I'm attaching the model as requested. If someone would care to take a look at it, the ship is on Layer 1 and the cylinders on the other layers are what I'm trying to cut into the ship to create windows. If I just do a boolean, it works but as stated in my initial post the edges are not connected, leaving gaps. If I follow the steps given above, I end up with the windows stenciled onto the hull and not cut into it.

Appreciate any ideas on how to handle this.

01-25-2012, 05:44 PM
Oops! Sorry, forgot to attach the file. It is attached here.

01-25-2012, 06:07 PM
fixed. Otherwise, when you Merge Polygons the subtraction ones will be merged into one (looking stenciled).

Added Traveler's tip, since it helps in more stressed meshes. Not the case here though

CTRL+U, Unweld (Both FG and BG)

CTRL+T, Triple (Both FG and BG)

Align Normals/Polygons (Both FG and BG) [Traveler]

Boolean (Just FG)

Select all polygons. Merge polygons. Merge Points (Just FG, unless you want to do something with BG)

Report :D

01-26-2012, 06:42 PM
Great!! Thanks for the help, it works now, much appreciated.

01-26-2012, 06:44 PM
Cool. Have fun :)

02-20-2012, 09:57 PM
Or, you can clean the booleans, like people have been doing since... well, i was doing it in LW 4 on the Amiga...