boolean misbehavin'

i made a plane and put some shapes thru it to make neat holes in the plane.
one shape at a time.
but it keeps fracturing the plane. i subdivided lots
any ideas - in 2.49b
thanks all


BB frontbogie.blend (537 KB)

Booleans are well-known troublemakers. Better to cut the holes manually – simply delete faces, then add a subsurf modifier for the rounded edges. Add extra edge loops where you want the edges to be sharper.

Something -very- important when using Blender booleans is the normals.

When there are inverted normals, the booleans will not work correctly. I opened your file and noticed all the meshes that are going through the plane have inverted normals (to see select one and go to Texture Paint and rotate around, you’ll see immediately there are see-through parts when the normal are inverted).

In Object Mode select all your shapes (but not the plane) and press CTRL+J to join them of them individually and in Edit Mode, press CTRL+N to recalculate the normals outside.

The booleans should then work after that, but you should reseparate each shape in Edit Mode ( press P then All Loose Parts) so you boolean the plane and a shape one at a time to avoid extremely long waiting time (or avoid Blender to just freeze)

benu, I like your approach, but one possible area of difficulty is adjustment of the roundness of the cutouts. It seems like one might want to add some edge loops ahead of time - before deleting the faces.

anon125, I did a quick check in 2.57 and I was able to pretty easily able get a nice result using boolean difference. In case there might be anything useful for you in it, here is a screencast

thanks all
ctrl N did it

Good thinking snowglobe. Actually, you could add the edgeloops just before deleting the faces, and then use box select to move them around as needed…

how do i distribute the objects evenly?

Good question; it will be interesting to see if someone has better ideas than I do. Seems to me the cleanest and fastest way is probably going to be to create them in the first place using an array modifier (if you watch my little video that’s how I do it there, along with mirror modifiers).

If you are trying to evenly distribute a bunch of objects that already exist, only thing I can think of off the top of my head is to use blender unit translations along with scaling.

EDIT: or just eyeball it, maybe

AHA! why didn’t i think of that!

Just because this is on the computer and in blender doesn’t make it too much different then
how things are made in the real world. All it looks like to me is a sheet of metal with punched out
holes and then bent into shape. You would just add a plane and delete the face and then model
the hole and then rebuild the faces. Then use an Array modifier to make a whole sheet. Now you could
use a Lattice to deform it into shape or Warp ( Shift + W ) which does a pretty good job of bending.

warp huh - never thought of that! thanks