SubD performance & snapping problems

Several problems with SubD can be observed in this small video:


  • After selecting three fairly simple SubD objects and choosing Relocate Gumball, performance in the viewports deteriorates massively… from smooth to around 10-20fps.
  • The Osnap targets highlighting for the Relocate Gumball snap seem to almost prefer the hidden objects (related to this, I wonder?)
  • There’s no Osnap in the int/end of the visible lines. This works well with normal nurbs objects.

can you post this file with a saved view that we can use to reproduce?

also do you have any customizations to your view mode?

If so can you try reset to defaults and see if it helps?

The file I’m working on currently is very sensitive, so I can’t send it.

However, I’m noticing more and more than it’s sufficient to have SubD models in the file in order to have huge performance issues:


Again, it’s especially prominent the moment there’s any outline drawing or snapping in the view.

None of these performance issues exist when opening the same file in Rhino 6.

Note that I did switch to the default view mode in the above GIF, and it didn’t help.

Are you running the latest version of rhino?
Help>check for updates

there have been some changes to snapping in later code.

please run the systeminfo command in rhino and post the result here-

I haven’t been able to do what you asked yet, but I just noticed something:

The performance problems potentially went away when I disabled a cross section I had active (but it wasn’t actually sectioning anything at the time, hence why I didn’t notice it… until it created some huge flickering, infinite looking planes to the side of my model).

that is entirely likely to be the issue…

does selbad light anything up ?