"Solid Control Points" editing

Sometimes basic Polysurfaces freeze my Rhino Instance when editing their control Points.
Even basic modifications (just in plan, no fancy 3d) usually compromise the file after some 10 or 20 times of editing the volume.
Usually the instance of Rhino “comes back” but this could take 3-5 minutes.

Does somebody know why, or how to avoid it?

Hello- do you find, after one of these freezes, that the polysurface faces have greatly increased in density (isocurves) That is likely if you are repeatedly editing solids - I would be curious to know what types of edits are done- if you have an example you an send me, or to my attention (Pascal) at tech@mcneel.com, I can take a look- there may be better ways to edit the objects as well.


Testing with a cube i can repeat some of Thorsten’s freezes using SolidPt editing. One anomaly is the density change if single points are moved. It seems that vertical cubes faces change in density while the top and bottom face stay clean 4 edge surfaces.

Using CTRL+SHIFT to select and drag edges around doesn`t change the density as much as single point editing using _SolidPtOn. Maybe this could help to avoid the freezing, it seems to be related.


SolidEditPointsFreezing.rar(1.7 MB)

Hello Pascal and Clement,

I could just remember this one from this morning, did some Points-editing,
and indeed, the iso-density raised for some of the srfs.
My edit for the (former) straight hollow sections was to manually (brutally) connecting them to share their haunch.


Hi Thorsten- I see, so you used SolidPtOn and moved individual points together to make the closed frame from separate, simple, starting extrusions- did I understand that correctly? The thing is, if the faces become distorted along the way and are then refitted to more complex surfaces to accommodate this, there are few circumstances where further editing will restore a simpler surface… so the upshot is that surfaces tend to get denser and denser.

(In short, it looks to me like we need to think a bit more about just how this command should be implemented.)


Yes Pascal. you got it right, that was my way of “quick 'n dirty” modeling.

It’s understandably that the simple surfaces become more complex when turning and twisting them, but the time-delay seems to be a little “off”…


SolidPointsFriction.rar(1.7 MB)

this one here is even more funny, the upper side of the wall is just an extruded curve, and I added a split on top, now even the rendermesh is disturbed.

Yeah… I see, in general, what you are trying to do- sort of SketchUp-esque editing, I guess, correct? You can do this with surfaces only to a limited extent but in a case like this example, I would also split the vertical side faces at the same location as you did the top face. That will help a little at least.


Hi Thorsten and Pascal,

i´m not shure if this is related to the density problem, but could it be that the solid editing tools are “affected” by the tolerance settings in these files ? Just noticed the relative and angle tolerance inputs in both files. The angle tolerance is 0 degrees.


Good catch Clement, I’ll check it out.


It is certainly faster at a more reasonable absolute tolerance - Thorsten, in any case, 1e-07 is probably not ideal as an absolute tolerance - generally between .01 and 1e-06 is the recommended range as I recall (from the developers)


thankd for both the ideas
splitting the volume once around the "edge"
and reducing the abs tolerance.

Have a nice day!

I think it was definitely the reduced tolerance down to 1e-05.
Solid editing works smoothly now.


Hello, I have the same problem with solid control points. Sometimes they work just fine, sometime they crash Rhino altogether. I tried the suggestions above but the problem is persistent. For example if I select all the control points on one side of the window frame and drag them the geometry updates without adding iso-curves but if I select the control points of one corner and drag, it crashes Rhino every single time. I don’t have good understanding of the limitations of the tool and any help will be appreciated. Thanks!

Is Rhino asking you to send in a crash report to McNeel?
Could you post the model that is crashing for you so that we can try to reproduce the problem?

I apologize for the misleading information. I just noticed that one surface of the poly-surface is bad (see image). And Rhino is not really crashing- it’s just not responding and I am forced to close it. This happens often and it’s hard to spot so I will have to inspect the geometry I want to edit every time. Thank you for the help!