I have Clayoo as a replacement for T-splines, and it's nowhere near as easy to use, but it can get a lot done. Requires some pretty tedious workarounds for what I do, but the alternative is to not have any sub-d at all. I've looked at Xirus, and been tempted, but for now I'm waiting on McNeel to get it together.

I will say that the new ToSubd command is GREAT for taking downloaded mesh models and quickly smoothing them. Not enough commands available yet to replace t-splines, but it is still somewhat useful.

Hi Jack,

Yes they are coming! But who knows when... Supposedly with the release of Rhino 7, they want to have full functionality of Subd editing. Meanwhile, there is a hidden command called "ToSubd" that will transform a mesh to a subd geometry (you need the latest Rhino 6 version).

Here you find more info about Subd's and also the progress that is being done by the Mcneel team:

https://docs.google.com/document/d/1BsNLtTj8s0J-7uBuuKDRWJq6VtOLe_WlgPi-oQ7SxoI/edit

Best,

Arie