All settings and tools for symmetrical modeling in Modeler are gathered in the Symmetry radial menu (Alt+X). Tools such as Manipulator, PolyPen, Sculpt Move, and Sculpt Relax support symmetry. For other tools, you’ll need to periodically run the Symmetrize tool to maintain symmetry in your model. An alternative method for symmetrical modeling is to work on one half of a model while the mirrored half is displayed in real time using a special Symmetry Instance object.

How to Model Symmetrically:

• Open the Symmetry radial menu (Alt+X).
• Activate the desired symmetry axis: X, Y, or Z. Since these are checkboxes, you can always see which symmetry axis is active each time the menu opens.
• If you need to use the inverted side, activate the Invert checkbox.
• If your geometry isn’t symmetrical yet, run the Symmetrize tool.
• Continue modeling with tools.
• Whenever you need to update the model's symmetry, always run Symmetrize.
• To finish symmetrical modeling, deactivate the active symmetry axis.

How to Model Symmetrically Using Instance Method:

• Open the Symmetry radial menu (Alt+X).
• Activate the desired symmetry axis: X, Y, or Z. Since these are checkboxes, you can always see which symmetry axis is active each time the menu opens.
• If you need to use the inverted side, activate the Invert checkbox.
• If your geometry isn’t symmetrical yet, run the Clip tool.
• Select the Toggle Instance menu item. This will create the symmetrical half.