TriRemesh problem with trimmed surfaces

I noticed something odd with the TriRemesh component. If I have this type of trimmed surface in Rhino, TriRemesh works as I expect when selecting via right-click → Set one Geometry. But if I reference the same surface and feed it through a Surface container in Grasshopper, the resulting mesh is not as expected.

Why does this happen @DanielPiker ?

Expected output:

Unexpected output:

Attached is the GH file with internalized surface geometry. I am running Rhino 7 SR16. (8.3 KB)

It seems that feeding the trimmed surface through a Brep container fixes the problem. However, is this intended behaviour? I find it confusing since the Surface container implies that it can handle trimmed surfaces as well, but TriRemesh cannot?

Hi @TuomasLehtonen

Thanks - Yes, I’m aware of this issue. It’s not intended, but an oversight I made in the way the object type is recognised (it turns out GH ‘surfaces’ aren’t really Rhino surfaces, but BrepFaces in disguise).
I’ll try and get it fixed, but as you found - passing a trimmed surface through a Brep component is a way round it for now.

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Shrinking the surface also helps… (11.0 KB)

It’s only the casting to Brep that makes the difference there - it works the same if you delete the ShrinkFaces line.
This is the naming issue that caught me out: