Symmetry in RetopoFlow 4

[jlampel]

Symmetry in v3 was based on the mirror modifier under the hood. In v4, we have direct access to the mirror modifier, so there is no need to duplicate that behavior with custom RF functions.

However, Blender also has a separate Mirror option in Edit Mode that allows the user to mirror transformations across any local axis. To be completely honest, the way it is implemented is great in theory but in practice totally sucks to use because very few operators actually support it. Basic transformations are mirrored, but anything to do with creating, deleting, or adjusting geometry in more complex ways is not.

So, to match Blender's current expected behavior, we simply need to... do nothing. Awesome, we can cross this off the list.

However, long term, we should try to improve the situation because mirroring in Blender is a bit of a mess. I think that after RF 4 has been released and has been proven to be reliable in production and we are in a good place to look at new features, we should consider:

• Adding edit mode symmetry support for all RF functions, including those that create or delete geometry
• Adding an easy way to interactively adjust the retopo object's origin and orientation and thus its symmetry plane ( Customizable Symmetry #1227 )
• Attempt to contribute symmetry support to Blender's most used tools, such as extrude, fill, inset, etc., possibly through a dev fund grant
• Attempt to contribute an improvement to Blender's retopology overlay so that the result of the mirror modifier can be seen while working in Edit Mode without On Cage being enabled