The Symmetry pill in the viewport toolbar mirrors your strokes across an axis, so a stroke on one side of the mesh is applied to both at once.
Its label changes with the state: plain Symmetry when it is off, then Symmetry: X, Symmetry: Y or Symmetry: Z once it is on and an axis is set, or Symmetry: ON if it is on with no axis. Its tooltip is "Symmetry settings - toggle ({0}), cycle axis ({1})" with your current key bindings filled in.
Settings
| Setting | Default | What it does |
|---|---|---|
| Enable Symmetry | off | "Mirror brush strokes across the symmetry axis." |
| Symmetry Axis | X | "World axis the stroke is reflected across (X = left/right)." Shown only when symmetry is on. |
| Symmetry Origin | (0, 0, 0) | "World-space origin of the symmetry plane - the plane no longer has to pass through the world origin." Shown only when symmetry is on. |
Keys
| Command | Default | What it does |
|---|---|---|
| Toggle Symmetry | X |
Turns symmetry on or off. If the axis was still None, it also sets it to X. |
| Cycle Symmetry Axis | Shift+X |
Steps X then Y then Z then back to X, and force-enables symmetry if it was off. |
Both keys, like the rest of the sculpting shortcuts, only do anything while a brush tool is active.
The origin follows the mesh
Symmetry Origin is an offset, not a fixed world point. The symmetry plane's actual position is recomputed as the live mesh's bounding-box centre plus Symmetry Origin, every time you activate the tool, toggle or cycle symmetry, commit a stroke, or undo/redo. That is what keeps the mirror lined up after the Transform tool moves the mesh - if the origin were a fixed world-space point, moving the mesh would throw symmetry off-centre.
The symmetry plane overlay
While symmetry is on, a translucent rectangle with a 4x4 inner grid is drawn on the symmetry plane, sized to the mesh's bounds plus 10%, and the brush indicator gets a second ring at the mirrored position. This overlay has its own switch, independent of symmetry itself, in Settings > Theme > 3D Viewport, and its own colour (default RGBA 0.25, 0.80, 1.0, 0.50 - a translucent light blue). Turning the overlay off does not turn symmetry off - it only stops drawing the plane.