# CSG failed, exception degenerate edge

I have an object made in blender which needs to prepared for 3D printing. It is relatively complex object (114k verts, 228k faces, 228k tris) which contains three separate meshes.

I separated the object by loose parts, checked for non-manifold geometry, converted ngons to triangles, and am now attempting to perform boolean Union on them. Blender shows Cannot execute boolean operation, and CMD displays CSG failed, exception degenerate edge.

What's going on here?

UPDATE:

Modifier seems to work without an error if and only if objects don't intersect. That is a problem, since all my objects intertwine. Object parts were designed to intersect. For instance, a person representing a sword. Sword is a bit thicker than the hole in the person's hand to ensure structural integrity of a printed model.

• I think it happens when two edges align just right, try making small adjustments to the location of one object to "break them apart". – sambler Mar 21 '15 at 5:38
• @sambler Boolean operator doesn't produce errors only when objects are not intersecting thus defeating its purpose. If I could "break objects apart", I wouldn't need boolean operator. – Mirac7 Mar 21 '15 at 13:15
• I had similar problem.The problem was solved by converting the tris to quads (Alt+j). – Benancio Dec 12 '16 at 20:54