Request: Y branch

Hi Xirus guys,
your kernel looks promising and i’m interested in it.
I’m asking you if you can show us how we can solve a common Y branch fillet using your supersmooth surfaces and how this translate into nurbs.


Hi Riccardo,

by ‘y-branch’ you mean similar to a piping bifurcation? Maybe you can upload a model / image of such an example…

Attached is a simple bifurcation system done with Xirus: one is a Xirus model and next to it the (exact) NURBS conversion (if you open it without Xirus installed, the Xirus model will display as a mesh).

If you can give me some more information we can create a video tutorial…

—daniel (11.6 MB)

Hi Daniel.S,
I looked at the model, I think that is a misinterpretation of the request from @skysurfer
and Your example imported in other CAD looks not good.

Y Branch (or multi blend):
So what’s significant here:

  1. Time
  2. Quality
    Here at 4:16 Min

Thanks for the clarification; The links you provide are very useful.

We are currently implementing a few features to simplify these kind of operations (i.e. continuity between “mismatching” topology).

Will get back to you next week.

You’re right, I screwed up the mesh (did it quick and dirty). Will be more careful next time.


I was thinking on smtg like this:

@eddi, @skysurfer:
attached are a few examples (3dm file). Top row is a G1 star-junction, middle row C1 star-junction, and bottom row C1 branch. Left column Xirus, middle mesh, right NURBS model.

These models are fairly simple and quick to create with Xirus and obviously the continuity and meshing can be improved (I believe both of you could do a much better job than me creating such models using Xirus, as I am just an engineer working on CAD-mathematics and not at all a designer).

Anyway: soon we will include more features to create and control continuity at irregular (star) junctions as well as for the simplified creation of branches. (5.1 MB)


Xirus for Rhino, Y-branch:

Xirus for Rhino, Y-branch with starpoint:

OK, so the super detailed levels of control you’re achieving here are GREAT.

The fact that the default method of matching edges takes so many steps is not so great.

Unless I’ve missed some Xirus features, I’m pretty sure that performing these kinds of connections is much faster in Clayoo. (Same is true of connections like the ones in your new double torus demo.) I can actually do a five-pipe connection with additional vertical pipes above and below in Clayoo relatively quickly…

BUT you can’t get anything like the detailed control you’re demonstrating with Clayoo. You’re kinda stuck with some level of inaccuracy and no ability to do intimately detailed editing of continuity, nor any way to ensure that you get even curvature analysis or zebra results on compound curved objects such as what one might need for auto body design and such.

So that makes this a fun little horse race. Will Xirus get it’s UX up to par first? Or will Clayoo add better detail editing first and fix it’s stability issues?

This feels like watching a CAD geek version of Top Chef from a distance.

Soon we’ll provide commands that allow to do these steps all together.

Our approach is:

  • first, complete the toolset so that users can see what is possible to do with Xirus.
  • second, implement a compelling UI / UX and automate commands and workflow operations.


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Hi Riccardo,

We have now a few commands available for fast and smooth y-branch creation. Have a look at this video:

Another Rhino-XirusCAD user (Mark Landsaat) has created his own mini-tutorial using our commands:

You might also be interested in the related patch commands:

You can freely download our latest version on

Hope this helps.


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