Changing SubD display in Rhino influences SubD processing in Grasshopper

Grasshopper
1

I have a simple Grasshopper definition applying a bend deform on a SubD. When I change the SubD display in Rhino from smooth to flat (and back), this changes the bending result. So, obviously, the “SubD display mode” is more than just a display mode. Is this intentional, a bug or am I missing something?

To see the effect you have to perform a Grasshopper “recompute” after changing the display mode.

ss_001
ss_0011950×843 150 KB

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bend subD.3dm (744.5 KB)

bend subD.gh (24.1 KB)

2

I’d say it’s a bug. My guess is it has something to do with the way Grasshopper stores SubD geometry and not the bend component. Internalizing the geometry prevents the difference. For other people reading this post, to recreate the effect, reference a SubD, bend it, then change the display of SubD elements in the RhinoDoc (Tab), then refresh the solver in Grasshopper (F5). Bake results are different too.