SolidPtOn wish (cutting plane function improvement)

I spend a lot of time sculpting forms with cut planes and it can be a labour intensive task. Rather than slicing a shape in this manner it would be helpful if I could move points or rotate faces without destroying the integrity of all other faces.

Solid point editing is quite powerful but it’s also fairly limited in some respects as it can often warp clean surfaces.

It would be great if there was an option to select planar faces and constrain the points and vertices of all faces to remain planar… I understand that this is a self defeating action in it’s present state but:

  • By adding a centre point or axis to a face so it can be rotated around when moving the control point(s).
  • Pushing and pulling the edges and points of adjacent faces in a planar direction - similar to linkage physics. It would mean the shape would change shape somewhat but you’d always end up with planar faces.
  • Or, slightly different to above, using the cut plane command in the background which acts in the same way as wire cut but can also add as well as subtract.

The way I see it working:

  • Select face and rotate with gumball
  • The face is rotated and areas that are added or subtracted during the command are shown as ghosted with different colours/shades.
  • optional - areas that have been subtracted can be left behind in a similar fashion to Wirecut.

Move faces.3dm (93.0 KB)

I haven’t seen this in other software but I think it would be a powerful addition for sketching.


Hi Andy - yeah, I hear you - Solid editing can go south pretty rapidly- it is not easy to solve, the way Rhino defines objects, I guess. Your suggested approach is new to me… Interesting idea, I have no idea how that planar constraint might be implemented of course - that is way above my pay grade, but I see what you’re getting at. Usually solid-editing requests/expectations are for things like moving a plane on a cut cone or sphere etc - where users expect the underlying cone or sphere to maintain its integrity and just be cut with the edited plane location and orientation- it makes perfect sense, and it’s easier conceptually for my few remaining brain cells to see how that might be done, but it also requires a different process, under the hood, than what Rhino has used, I would say.


Hi Pascal,

I was thinking about a sketching rather than a finished model, however sketching with solid editing can leave a lot of work to bring the form back to a usable state. I envisaged giving the model a base/CPlane by selection and then allowing the edges and vertices to move in a similar way to linkages, but with a constraint that made sure they created a planar surface. You could stretch it or constrain edges so that the form would change shape but not size. Like dragging the edge of a cube to form a rhomboid shape.

I guess one way around this problem could be to have a wire cut approach to cut planes but the solid remains active where you can revolve/move the plane while selecting which side of the plane/slice to hide. Maybe a bit like a clipping plane?

Another way to approach this could be to have multiple clipping planes applied to an object but have a way to bake the clipping plane so that you are left with a solid of what’s visible?

Convert clipping plane to cut plane and remove the bit that is invisible?


Perhaps something like this for cutting plane function, Pascal:

Hi Andy - yeah - that is the more usual expectation, I would say, for solid editing.