Should the ExtrudeSurface method be influenced by the curve direction?

I noticed that I can get different results when extruding a surface depending on the curve direction. To me this doesn’t make sense. This is how the method is supposed to work according to the help file:

image

But this is how it actually works:

But if I flip the direction of the curve, the extrusion is created where I would expect it to be (following the curve).

image

This doesn’t seem like it’s working correctly to me. I don’t think the curve direction should be a factor at all.

Thanks,

Dan

Hi @DanBayn,

Can you post a model and your script?

– Dale

Hi @dale,

Here is the model and the script.

ExtrudeSrf test.3dm (155.7 KB)
ExtrudeSrf_test.py (201 Bytes)

Toggle the curve direction and try the script. Toggle it again and repeat. You should see two different results.

Thanks for looking into this,

Dan

Hi @DanBayn,

Based on your geometry, I can see your point. But what about this case?

The low-level extrusion function does take the curve direction into account. If it didn’t, you’d need to provide additional input to help the function figure out the correct direction. Probably easier to just orient the curve.

– Dale

Hi @dale,

Yes, you make a good point. I will deal with the curve direction as you suggest.

Thanks,

Dan