Extrude curve into solid - bug

Extruding offset curves (or donuts) with solid option, shows correctly during feedback, but is not solid when command ends.


Hi @ThomasAn_

I just tried this without being able to repeat your problem. Could you post a model with curves that won’t extrude into a solid? And let us know the version number of your Rhino?


It’s Rhino7. There is no model needed. Just two circles as shown earlier.

Unfortunately (in this context), when I use “just two circles” I get correctly a closed polysurface on extrusion - which is why I asked if you could post a model with two circles for which it doesn’t work.

The full version number would be helpful. It is on the splash screen. Mine is 7.8.21160.5001, 2021-06-09.

You sure you are using ExtrudeCrv ?
Untitled.3dm (29.4 KB)

My version is" (7.8.21160.5001, 2021-06-09)
Does not create a solid here.

Hi Thomas,

I get a closed polysurface extruding your curves and yes, _extrudecrv. May I ask what is telling you that your polysurface is open - I don’t see that in your video?

It seems to work here - on your file and with same Rhino version as you…

Do you get the isocurves on the top ? or are they missing ?

If you are creating polysurfaces you get the isocurves. If you are creating lightweight extrusions you don’t. But that doesn’t mean the object is open. Select the object and look at the feedback in the command history… Or look at the object property details.

If you extrude simple objects like circles, Rhino defaults to creating lightweight extrusions. This is a throwback to days when PCs were feebler and it helped to conserve resources. With modern kit this feature can be turned off in the Options / General page so every solid is a polysurface.


1 Like

It’s been throwing me off. It shows the isoparm during active feedback and then disappears. That’s a UI disconnect. All this time I’ve been opting for planaSrf first to make sure the top is indeed there.

It’s a UI shortcoming:
Looking at this visually you have no idea if it’s closed or open.