I have a problem with this closed polysurface

Rhino Rhino for Windows
,
1

It says that the object is a closed solid but visibly it has openings and I have trouble fixing it.

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image1333×750 401 KB
part 2 Grivna piramidi.3dm (888.3 KB)

2

is a visualization problem because that surface has some weird edges there:

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image1512×773 43.2 KB

if you extract those tini surfaces and the big one and run Cap, it works ok
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image1512×773 16.3 KB

3

Thanks a lot!
I tried the same thing with this similar object, but this time it did’nt work.
grivna piramidi.3dm (1.1 MB)

4

you have the same situation in both ends.

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image1210×722 88.4 KB

5

When i remove the small surf aces and cap everything it still stays as an open polysurface
grivna piramidi 1.3dm (1.0 MB)

6

you have some bad trims and some small disjointed surfaces.

simple fixes… extract, untrim, merge edges, retrim, etc…