Create a solid Between two surfaces

Hey guys,

As you can see in the picture i have two surfaces. I want to create a solid from the bottom surface to the top one.
At the top it has to be flat.

Hi @nymphius,

The general idea is du use _Dupborder on the surface and _ExtrudeCrv on said border.
Splitting the extruded border and the top surface with eachother and then joining the results will give you the desired result

oh ok that looks sick but when i try to extrude it, it says: “One input was not extruded because it would have made an invalid surface.”

You could also copy the duplicated border upwards and _Loft between the two, if that does not work either it would help if you could post your file

Hey… the loft thing works. but the problem is it always creates a open polysurface when i split.
i tried extruding the srf and then split it by CreatSolid and it looks alright but for some reason the top is invisible even when its a closed solid… im so confusedSurface.3dm (1.7 MB)

When i go to rendered perspective the top surface is invisible. is it maybe a visual bug?

No its a problem with the geometry,

The trimming border folds onto itself in the Z direction so extruding into Z makes a self-intersecting surface, which is why _ExtrudeCrv is complaining:

If you raise the file tolerance to 0.0001 units it works, as rhino can detect enough space to not consider the surface bad. But it would be better to fix the outline you used to trim this surface.

This is the result with the raised tolerance, you can clearly see the problem with the outline folding on itself:

Surface.3dm (2.4 MB)

allright. Thank you very much! The Surface is created through a point cloud, its a very fragile thing. I have to get used to it.