Better edit/sculpt mode mirror system
I think what may improve working with x/y/z mirror enabled is to have all vertices contain an id based on the axis.
This will work only if the mesh has the mirror modifier applied or with "Symmetrize" is used. What should happen there is to have blender read the mesh after those and find the matching vertex positions and edge connections and then give those vertices an id. It can do it in all three axis and store them so they can be used when a mirror axis is enabled from the top right. That should only depend on what axis is the mesh mirrored on after applying the modifier or symmetryzing. Modifier applied with X axis? Give the vertices the respective ids for X axis only. Modifier applied with Y axis? Same thing but on Y axis etc
This should allows us to have a nicer workflow when modifying a side of a mesh in edit mode.
And I think this would work great in sculpt mode too, so that when the mesh is perfectly symmetrical, the sculpt tools will accurately reshape the parts of the mesh on both sides with no slight inaccuracy.
Like in this image example:
2 Comments
One of the biggest benefits of this approach (in my opinion), would be that symmetrical meshes could be deformed without mirroring, and later have mirrored sculpting changes accurately reflect those asymmetrical deformations.
I think this could be a great addition to the already existing implementation of X/Y/Z mirroring. I could see this being added as a "relative symmetry" option, and keeping the current origin-based X/Y/Z mirroring as "global symmetry".
A great example of a common use case, would be the typical "production level" character modeling workflow. Since character faces (and often clothes) are mostly symmetrical, it is common to sculpt using a perfectly mirrored base mesh to establish the general shape and form of the face. Once you are happy with the general shape, it is common to "break symmetry" to work on the finer details/expression to achieve a more realistic sculpt. The issue is that once the mesh has asymmetrical deformations, its no longer possible to make symmetrical changes that reflect the deformed mesh accurately, therefore the artist needs to do twice the work by manually sculpting both sides.
[ freeimghost ( . ) net/images/2025/05/14/mirror.png ]
Another example would be sculpting clothes. Imagine sculpting a Tshirt, provided you use a symmetrical base mesh, you could sculpt asymmetrical wrinkles, and later add symmetrical stitching/seams that properly conform to the asymmetrical surface.
(ps. feel free to add the image I linked to your post, apparently you can't directly add images to comments)
And if a user does something to a side of the mesh that could potentially affect the symmetry, the following actions could happen.
Adding new geometry would not affect the existing vertex ids, but it will not create new vertex ids on the newly created geometry cause its an asymmetrical triangle.
And if parts of the geometry is removed, the ids on the other side will be also removed.