Cleaning up after a Boolean Intersect

[Anonymous]

I'm trying to subtract one mesh from another to create an imprint of an object in another surface.  I've carried out a boolean intersection to do the subtraction, but the result appears to have created 2 separate surfaces (one white, one pink) separated by a thin blue line.  The geometry looks good, but if I try to repair the mesh it just fills over the imprint with a flat area, and if i try sculpting, the edges between the two surfaces appears to come apart and create gaps.

How can i convert the object above into a single manifold mesh so i can start sculpting on it to smooth the transitions out? I've experimented with Join and Weld, with no luck. Please help!

[Anonymous · Accepted solution]

Guess it's a typo when you said you used BooleanIntersection?

It should be BooleanDifference instead?

Your object B (the one activated as the second object to subtract A-B) seems to had flipped normals (was striped in pale pink?)

If so, it would be easier to do BooleanDifference once again. 

(To flip normal direction: Go to SELECT, SelectAll and run SELECT/Edit/FlipNormals. Now it should be grey as the other object is)

Now BooleanDifference should work as expected.

If you prefer to fix your result:

SELECT a bit of the white surface and hit E to expand to connected faces. Hit I to invert the selection to the flipped region and run SELECT/Edit/FlipNormals.

Now select opposite regions on both sides of the blue line and run SELECT/Edit/Bridge. This connects both pieces and you get a single hole.

Run EDIT/Inspector to close it.

[Anonymous]

Fantastic, flipping normals sorted it out! Thanks MagWeb! 

Indeed I was doing a BooleanDifference not an intersection