Creating meshes on nudge?



let’s move a polysurface with the nudge keys.
We take a simple box, the perspective viewport is set to Shaded.
In the Top viewport, we nudge the object by Alt+Cursorkey.

On every single nudge, the command area reads ‘Creating meshes’.
This can’t be right, as the object doesn’t change.

On complex objects, it takes very long and nudging is not funny then.



Hi Charles,

looks like be a bug with polysurfaces (and extrusions), if i select a subsurface of the polysurface using CTRL+SHIFT, then nudge it one step forth and one step back, i can nudge the whole polysurface afterwards without the “Creating meshes… Press Esc to cancel” message.

Tested with an extrusion, this happens as well but not anymore after exploding and rejoining it.

Btw. do you have a spaceball / spacemouse connected ?



Hi Clement,

Btw. do you have a spaceball / spacemouse connected ?

No, I haven’t.
Why do you ask?



Hi Charles,

i´ve been thinking that if such thing is connected, Rhino constantly builts the render meshes to calculate the auto rotation center… even in Wireframe display mode.


(illuminated paperweight owner)

(Pascal Golay) #5

Hi Charles - extrusion objects (by default Box makes these) do not store meshes and these are always recalculated. However this should not be the case for polysurfaces under normal circumstances.



Hi Pascal,

Aha, I didn’t notice before.
Seems this is the downside of lightweight objects.

Wouldn’t it make sense to at least store a pointer to the meshes of an extrusion?
With a simple box recreating meshes doesn’t harm, but on more complicated objects it does.


(Willem Derks) #7

Hi Pascal,

That explains the extreme lag I experienced working with this model (cropped to not reveal it)

The patterned sheets are all extrusions and working with the file was tedious. Probably (also) because of this reason.
Please reconsider this constant remeshing. I wonder what takes more time; transforming both rendermesh and extrusion, or transforming extrusion and remeshing. I undertsand you do not want to save meshes in the file, but during a session IMO the mehses should not be recalculated if a transformation is quicker.



Hi Willem,

what happens when you convert them to polysurfaces?
Is it faster then?

If so, I wonder what extrusion object are really useful for.


(Brian Gillespie) #9

I think Extrusions may be misrepresented here a little. The goal is to remesh the extrusions whenever the model is read from disk, not when the view changes. In an experiment I just ran on the latest in-house code, I was able to extrude a series of closed planar curves into an Extrusion object with holes. When I nudge that object, the meshes are not recreated.

If you are seeing something different with the attached extrusion-nudge-test.3dm, please let us know.


@brian if i open your file and nudge the extrusion i don`t get this error. Once i set the displaymode to Shaded for the perspective view, then nudge the extrusion in the top view, as Charles described in his first post, the error happens.


(Brian Gillespie) #11

Yep, I see that too. Silly me - I forgot the shaded mode part.

This just seems like a bug to me. Added as

(Willem Derks) #12

Hi Charles,

Well the extrusions are in many ways more lightweight. Conversion to polysurfaces adds a lot of overhead information in the form of definitions of all surfaces defining the edges of holes and outer boundaries of the sheet.
I see this issue with remeshing was reported as a bug: