Fillet Edge and Unroll Surf

I’m looking to fillet the edge of two simple surfaces, then unroll the brep. However, I cannot find either of these commands in Grasshopper. Do they exist, is there a plug-in that has them, or do you have to do this “longhand”?


They do not exist as GH components. I think neither is available as an SDK method, so they are only accessible via the Rhino commands.

Both FilletSurfaces and UnrollSurface are available as Python rhinoscriptsyntax and RhinoCommon methods, so it should be possible to create a custom Python component… no?


FilletSurface yes, FilletEdge no. But you’re right about unroller, it has support for Breps now.

Sounds like there is potential but with some effort.

I have no knowledge or experience with Python. How would I go about figuring out how to script the unroll command as a Python component into GH? Am I even understanding this correctly?

The fillet edge/ fillet surf I could likely do “longhand” in GH without too much trouble, so I’ll probably go that route with that particular command for this project. Unroll is the command which would be more helpful to have in GH.

Before this even goes too far, will the Python rhinoscriptsyntax allow (as Rhino does) for unrolling not only a Brep but for unrolling circles, points, and text (single-stroke font) on that Brep? If not, then I might have to do this in Rhino, not GH, anyways.

Thank you,

Actually, it does exist as a part of segghcommon GH plugin. It is called Seg_Unroll and you can find it under Srf tab, but I am not sure if it allows for polysurface unrolling.

Hi @Piotr

I searched segghcommon on Food4Rhino but found nothing. Where could I download the plugin to test it out?

Thank you,

Hi Matt
I can see it disappeared from Food4Rhino, but attached is an older version I am using seg_ghcommon.gha (528.5 KB).

Well, I installed the plugin into GH, tried to unroll a surf, and got a message that says the plugin has been updated, and to download the current version from

It appears that the GH component has the ability to unroll surfs, points, and curves. Nice.

When I go to the webpage, I am denied access.

Anyone know who allows access?

Thornton Tomasetti’s TT Toolbox has an unroll surf with points and curves included. Rock on.