Extensions:2.6/Py/Scripts/Mesh/Remirror

Remirror
Non-destructively update symmetry of a mirrored mesh

UI location	View3D » Object » Mirror » Remirror
Usage	Select object that has lost symmetry, then run Remirror.
Version	0.9	Author(s)	Philip Lafleur
Blender	2.63	License	GPL
Category	Mesh

Executable information

File name	mesh_remirror.py
Current version download	http://projects.blender.org/tracker/index.php?func=detail&aid=32166&group_id=153&atid=467 (under Attachments)

Overview

Before

After

Remirror reestablishes symmetry in a mirrored mesh. Symmetry could be lost when, for example, during a mirrored sculpting session, the user hides parts of the mesh that are symmetrical to the parts being sculpted.

Remirror is non-destructive, so UV coordinates, etc. are not changed, and the result can be used with the Multires modifier's Reshape function.

The script works by following symmetrical edge paths from the central edge loop(s) of a mesh and updating the coordinates of vertices along the way. Therefore, as long as the mesh topology has not changed, any deformation can be corrected.

Preconditions

• The mesh must have continuous normals. In other words, normals on a continous surface are all pointing "out" or "in."
• The central edge loop(s) must be (mostly) centered at 0 on the mirror axis.
• A vertex cannot have more than one gap in the faces surrounding it. More precisely, a vertex cannot have more than two edges connected to it that are only connected to one face. (This could probably be fixed.) See below:

This is okay

This won't work

Options

• Axis: The axis along which the object was originally mirrored. (Default: X)
• Source: The half of the mesh that will be used to update the other half. (Default: Positive side)

Usage with Multires

1. Duplicate the Multires object. ⇧ ShiftD
2. With the duplicate selected, make sure the Multires Preview field is set to the desired resolution, then click Apply.
3. Apply Remirror to the duplicate. Object » Mirror » Remirror
4. Select the duplicate, RMB
5. Then select the original. ⇧ ShiftRMB
6. Click Reshape on the Multires modifier panel.

Known Issues

• The algorithm that finds the central edge loop(s) could be improved.
• Error messages aren't shown after adjusting the options.
• Disconnected parts of the mesh that do not intersect the plane dividing the chosen axis are not affected.