Booleans help
 

Im trying to make a 3D Hand and I have a problem, when I select the palm of the hand and a finger and I go to Booleans and click on Union the modell disappears :confused:
where did I go wrong?

look in this forum about that topic. you will find enough stuff about it.

Your Boolean Operation is failing for 2 main reasons.

1. Your Hand and finger geometry is not intersecting correctly.
2. Your have non manifold geometry on eith or both of the objects.

Really to model a hand you dont want to create all seperate geometry and boolean them. You should create the fingers from the existing geometry is far easier and leaves on errors like the one you have now...

umm...is this good? xD

http://img248.imageshack.us/img248/6303/73812851hi1.jpg
http://img463.imageshack.us/img463/2793/23290496sf9.jpg
http://img76.imageshack.us/img76/931/91843296rv6.jpg
http://img62.imageshack.us/img62/682/53982829ex8.jpg

The geometry of the thumb is not all the way in, some of it is still outside the hand.
The fingers geometry is over lapping. So if you boolean all of them at once, then it will just disappear.

How I would approach this is to get all the verts for the thumb and fingers lined up against the hands existing geometry delete any faces that exist in between the fingers/thumb and hand and the do a Polygon > Combine. Once thats done merge the individual verts to make the hand whole.

thank you :D, all that was needed was to delete some faces from the thumb ^^