T-Splines problem

I have installed t-splines 4.0 plug in (I’m using Rhino5), and it has worked until I closed the program. Now everytime I open it a window pops up that says “Done installing plug-ins, press close to continue” and bellow “Error loading- T-Splines UI”. The commands don’t work. I activated the liscence succssesfully (or so I thought).
I have tried installing again and even tried 3.5 version of t-splines but the same thing hapens.
Do you think you can help me with this?

maybe making a clean reinstall? I mean uninstall, clean registry and install again?

Hey @milabrstinic219,

Did you know Rhino 7 supports SubD surfaces?


– Dale

I have tried again after reading your reply, but the same thing happens. After being installed, closed and opened again, the same window pops up and when I try to use any T-Splines command it says “Uknwon command” (“_tsBox” for example).

T-Splines no longer exists.
T-Splines was a SubD modeling plug-in for Rhino.
Rhino V7 now has native SubD modeling tools.

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A more accurate description would be that T-Splines is no longer for sale nor supported. It certainly does exist for those of us who bought T-splines when it was available. While I no longer use it I suspect there are still many who do even though they are limited to Rhino 5.

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Point taken. Certainly it still “exists” in the sense that the people that purchased a license when it was a viable, useful product, still have and use it.

The company that developed T-Splines no longer exists.
The developers are no longer working on that technology.
The product has been abandoned.
It has been many years since a new license could be purchased.

We avoided developing our own tools to not compete with our 3rd-party developers. When T-Splines “went away”, and no other developer stepped in to fill the void, we decided to take on the project and make SubD tools part of native Rhino.

And here we are.


Sure, I understand what you’re saying. However, as I Rhino5 user, T-Splines is my only option.

Might look at this thread:

Hi Dale, I would love to have a one to one conversation about SubD… I’m an avid user of T-splines, I still use Rhino 5 because of this. I do have Rhino 7 and I’m trying to start to use it full time, but SubD still needs a lot of work to be done. Is there a way to have this conversation? I have several notes to make SubD better. Thanks!

Posting your list here is the most useful, that way we can have others chime in and comment to get a quick consensus on what needs to be fixed before we start burning dev hours.

Fwiw @dalelear is the subd lead dev.

Which Tsplines functionality do you miss the most?
For me it is the retopo functionality and the way creases end.
Also the selection of subjects is sometimes difficult.
But I have left now Tsplines completely, and do all my SubD modeling in Rhino.

fading creases is high on our wish list, as is better retopo tools-

stay tuned, subd is in active development now that it’s a 1st class rhino citizen-


Hello guys,

Let’s see, I have several functions ( for me) that need to be improved.

1- Symmetry (Reflect in SubD) : Right now this command can only do ONE symmetry plane/axe at a time. There should be able to have 1, 2 or 3 axes of symmetry. Also there is no radial option. This two are very important for work flow.

2- Retopo Snap: A big YES. We need that.

3- The right click button command ( Remove Symmetry) is not working anymore. I know you can select R and it goes away, but for me is time saving to have the right click mouse function.

4- Joining points (Weld points in t-splines), I would love to have that back.

5- Match Edge: Also very important.

6-Finaly and most important in my opinion. The conversion from SubD to Nurbs ( and vice versa ) needs to get better. I design and 3d model jewelry and tiny earbuds on a regular bases. It gets really hard to substract boolean an object, and then Fillet the edges. I would love to screen-share and show you all the issues I’m getting. It’s crazy difficult to get water tight geometry.

Maybe that I’m here … Filleting function has gone backwards in my opinion. It does a terrible job in all the pieces I’ve tried to use it.

I hope this gets in to the right ear. :slight_smile:

I still love Rhino, but SubD needs more work.


I have a few more bullet points haha…

Bridge command: There is no option to follow a path/curve.

Crease and Remove Crease: I would make this just a ONE button command. I already modified it ( right click mouse) for my custom toolbox pop-up, but makes no sense to have two in my humble opinion.

BTY, great job on Multipipe inside Rhino and Grasshopper!

see below

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For now, I can share this screen shots about Symmetry button. I will send screenshots about filleting issues.

Image one shows that there is a Right click button command but in the second image, says Unknown command. It shows the R option, but I would like to avoid this. Milliseconds I know LOL, but I work fast.

Can’t wait for this new updates then!

There is a lot of room for Rhino SubD to be improved. The good news is that on any given day, two or three developers are working on improving some aspect of SubD in Rhino 7.

In particular:

Thanks to lots of hard work from @lowell , there will be a substantial number of SubD symmetry fixes in Rhino 7.6 (scheduled to ship on May 11).

@pierrec is investigating several ways to improve to ToNurbs (SubD to NURBS) and we have lots of active bugs in this area.


Awesome! looking forward to leave Rhino 5 behind…

And thank you for your quick responses.