When extruded, the ceiling cannot be covered

The ceiling is not covered when extruded with the ExtrudeCRV command.
I fixed the self-intersecting curves, but it did not fix the problem.
Could you please verify the data as I do not know how to solve this problem?


aaa.3dm (173.2 KB)

Hi Tatsuya - the curves are somewhat messy - try:
Turn on CurvatureGraph, with a scale of ~90 or so - where you see the graph spiking,
image

look closely and if needed simplify and repair:

image

I would redraw parts of that inside curve with clean new curves that use the existing messy curves as reference.
-Pascal

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Thank you for the advice.
It is difficult for me to redraw this curve anew.
So I fixed the spikes in the graph by smoothing them out.
But the extrusion ceiling wasn’t generated.

Hi Tatsuya -

When I open your file, select both curves, and run ExtrudeCrv with the Solid=Yes option, a bottom and top surface are created here:
image

If that doesn’t work like this on your machine, could you also post the file with the non-capping geometry?
-wim

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Hi Wim,

Thank you for verifying this.
I post the file with the non-capping geometry.
bbb.3dm (351.2 KB)

Hi Tatsuya -

Thanks for that file. It looks like this object is already capped and closed but has an issue with the display meshes. Extracting one of the surfaces and joining everything again will clear that up:

2023-06-07 Capped Object

It appears that something goes wrong when creating the extrusion object from those curves. If you set the UseExtrusions command to Polysurface before extruding the curves, the resulting object will shade correctly right away.
I’ve tested this on the current Rhino 8 WIP and that looks to work correctly with extrusions as well.
-wim

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Hi Wim,

Thank you so much!! amazing!
I tried,I can do it.