Split failed BUG


I ran into this while working in 5 and tested in 6. Both Split and Boolean Difference fail on this polysurface, in that particular place. I attached the file containing the polysurface and the surface that i was using to split.

Your objects don’t appear to intersect cleanly.

Intersect the two objects.
Invert the selection to isolate the new curve.
Check it’s properties and notice that it is an Open curve.
Run CrvEnd and CrvStart on the resulting curve.
Zoom in close and you’ll see an overlap in the ends of the curve.

That’s why Split fails.
Inspect your surfaces to figure out why they aren’t as they visually appear.

It looks like the polysurface was “forced” together.
Explode it.
Run RebuidEdges.
Try to Join it and it’s not a closed polysurface.
Fix that up and you should be golden.

If you delete the two long planar surfaces that won’t Join after rebuilding the edges, Loft the long edges to make new surfaces and Join them, then you get a good solid that will intersect and Split as expected.

Hi @John_Brock,

I was running ZoomNaked to check but I got “Object does not have naked edges”.

Your solution works, the intersecting curve is indeed open.

Did you happen to use JoinEdge when you built the polysurface?

If i remember correctly, I made it using only CutPlane - Split - Cap starting from a Box.

Did you by chance do that and then later tighten up the tolerance settings?

I might have played with the tolerance hoping that I might get the split to work.

The tolerance settings in the file as you sent it seemed fine so I did not change them. But at those settings, Exploding, RebuildEdge, and Join did not make a closed polysurface. Deleting the two unjoined surfaces and then Capping didn’t work either.

Yes, I tried to delete one surface and then cap and split, then i tested again by deleting the other surface and caping. Cap seems to work, even though it creates a buggy surface.

por curiosidad: if you detach the bottom face and then _EdgeSrf with the four edges all works with good solid
the bottom face edges are not in the same plane, also there is another (top angled) face you cannot use with _cap
Why? the bottom face intersect well…