Wish: Better SubD tools

I struggle to use SubD in an efficient way, despite having good experience with subdivision modeling in 3ds Max since couple of decades. I can’t find tools in Rhino’s SubD that were extremely useful in 3ds Max. I will give you a few examples:

  1. There must be a tool that makes a bent bridge between selected faces or border edges, with ability to change the number of segments and amount of bulging (smoothness).

  1. 3ds Max allows to use a spline to define the shape of such bent bridges, so it will be great of SubD also allows to use curves for the same purpose.

  1. A “Target weld” tool to move and merge a point to another point. Those two points should become a single point. ! _Stitch fails there.

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Hi @Rhino_Bulgaria .

I found those working to me.

  1. Before Bridge make small extrusion of those faces.

Then delete extruded faces’ caps.

Then make Bridge on edge loops.

If you do not like the result of Bridge, consider SubDSweep1.

  1. If you turn On SubD points and do not use preselection
    Stich will provide command-line options to which point to stick.

Hope this helps.


Hi @Screamer , thank you for the nice explanation. It’s pity that ! _Bridge is doing weird things if the input SubD edges are not extruded preliminary, and will only work properly with extruded edges. Here is a comparison between both methods. Note that the settings are exactly the same, but the end result differs a lot:

In my opinion, the “Bridge” tool must take into consideration the normal direction of the two borders and make a better bridge surface rather than trying to connect them in a nearly straight fashion even with “Straightness” set to 0%.

! _Stitch is also counter-intuitive, because its purpose is to literally stitch (combine) two points into a single one, but it fails to do so in so many occasions. Pre-selection should not stop it from doing its job properly. The proper way to do it should be by pre-selecting two control points, then press the “Stitch” icon and… voila, the points become a single point. Just a single mouse click! Instead, Rhino creates a point object with the “!” symbol and the following warning:
“Invalid input geometry.
Defects are marked with dots and defected components are selected.”

That’s weird. I’ve never seen this before.

It happens all the time when I pre-select two points located in the same coordinates (basically I moved and snaped one of them to the other). However, when I run the “Stitch” command first and then click on the same two points individually, the tool works most of the time, but sometimes will still fail. It has some weird conflict with shown SubD control point or when the Filter is set to “Sub-objects”, because then Rhino is confused between SubD control point and SubD vertex, which is literally the same point.

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Same here working for some years in Modo the tools are powerful and the most important thing for Rhino to increase SubD adoption is Selection workflows.

Therefore SubDs have to be recognized and tools should work differently on a SubD compared to Nurbs.

The brush selection which is fast and intuitive in Modo is not existent in Rhino.

They used their brush selection which is coming from the stone age.

If you have trouble to select and not be able to work with SubDs intutively there will be no adoption.

Rhino could be termendously powerful, if it will find ways to combine both worlds and let them work properly easy and straighforward.

It is also important to make history work with SubDs in all commands.

But construction capability alone could warp Rhino modelling workflows (combined with SubD direct modelling) to another dimension.

I do not want to use other tools. Would love to be able to do everything in one package.

The chances are good that when coming to direct intuitive modelling Rhino could become the gold standard.

Also parametric approaches with Booleans would be very beneficial.




What does it do? (Rhino has SelBrushPoints command - it can select control points.)

@andrew.nowicki like also in blender or 3dsmax you have the mouse pointer turning into a brush, every mesh, vertex or edge you select by simply brushing over them will get selected or deselected by pressing Ctrl or Shift.

The SelBrush command:
Rhinoceros Help - Selection commands | Rhino 3-D modeling (mcneel.com)

Here is a brief video how this works in Modo:

A clever way to dynamically switch between brush selection of different sub-objects is to first select either a point, an edge or a face (polygon mesh or NURBS surface), then Rhino should be smart enough to understand that the next sub-objects you want to select will be of the same type. For example, if I click on a control point, Rhino should switch to selecting only control points with the brush circle. However, clicking on some edge should switch to brush selection of edges. The idea is to prevent selecting different types of sub-objects with the brush circle.

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Certainly something to consider. Makes no sense to select a vert and then a face. Beautiful idea

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You can get similar results in Rhino by turning SelectionFilter > Sub-objects on and using SelBrush > Crossing command. Rhino documentation says that SelBrush can also add objects by holding Shift key and deselect objects by using Ctrl key. This is not true - the Shift and Ctrl keys do not work with the SelBrush command. (The Shift key changes diameter of the brush.) These keys work with the SelBrushPoints command and with ordinary mouse clicking.

To complicated. Nobody will find out. should be totally intuitive.

I currently checking to move over all subd work over to 3dsmax or maya they have a indie edition if you make less than 100k/y for apx 350€ - as modo is dying and has almost no community and learning material to understand the whole software. very sad when companies acquiring companies and don’t know shit.

I like Rhino user interface, but we need more debate about it. This forum may be the best place to compare user interfaces of different CAD programs because Robert McNeel & Associates sometimes listens to the users. It happened to me a few years ago - curve piping now supports linetypes, so it can look like stitches.

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Also proper training material. What you describe there is lot of these extra tips and tricks and most of the people that work with Rhino do not know about all that. Hence the true power of Rhino is not marketed well. Which happens in in-depth easily follow-along courses (no tutorials) which first explain every detail and then apply that to complicated real world projects. As well as explaining all customization possibilities as this could speed up workflows tremendously (from icon clicking which many do to intuitve usage of scripts and aliases and shortcuts as well as customized viewports).

Only that could transform a beginner to an intermediate to an advanced pro.


What happens when you start SelBrush > Crossing command and hold the Shift key? When I do it, Rhino changes diameter of the brush while I move the mouse.

if you read the documentation carefully:

  • SelectionFilterNone
  • RealTimeSelection=Yes
  • Ctrl+Shift


I have read documentation carefully. My computer behaves differently than your computer.