Live symmetrical drawing

A common technique in poly modelling is to turn on symmetry and move vertices, edges, etc. I’m wondering if there’s some way this can be activated for Gumball, or if curves can be drawn symmetrically live?

Or for example, rather than mirroring this part after I trace it, or when I want to move points on a curve.

Symmetry command.


Toolbar Menu

Curve Tools

Surface Tools|Transform


History enabled

The Symmetry command mirrors curves and surfaces, makes the mirrored half tangent to the original, and then when the original object is edited, the mirrored half updates to match the original.

History recording must be on when the command is run.


  1. Select a curve or surface.


  • If you select the curve first, the start of the curve is changed.
  • If you select the curve after you start the command, the end of the curve nearest to where you select is changed.
  1. Pick the start of the symmetry plane.
    This is similar to the Mirror command.
  2. Pick the end of the symmetry plane.

Command-line options
Continuity Determines how the continuity between the mirrored objects is handled.


No constraint.


The mirrored curve or surface will connect to the original with G0 continuity.


The mirrored curve or surface will connect to the original with G2 continuity.

See also


Create a mirror-image copy of objects.


Makes a SubD symmetrical across a reflection plane and merges both sides into a single SubD.

Rhinoceros Help

Great, thanks!