SubD symmetry gets discarded after adding face

When adding a new face to a subD object (with symmetry activated) +join, the symmetry is being discarded and the mirrored object becomes “baked”. What am I doing wrong?

The preserve SubD symmetry option is enabled…

can you post a file and steps to repeat?

Outcome:

symmetry_join.3dm (2.5 MB)

yep I’m seeing that here too-

thanks for reporting this-

RH-89371 subd symmetry is not preserving

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@eg1 Join SubDSymmetry=Preserve only works when both SubDs being joined have the same symmetry. You can use Reflect on the small face before the join, to get the result you are looking for.

Or use 3dFace or another command to directly add a face to a symmetric SubD.

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That worked, thank you for clearing that up!

But does the same mirroring process need to be repeated for every face + join in order to add a face to a SubD face that cannot be extruded linearly? If there was a quicker way, I would appreciate it. Quite a lot of work just to add a polygon.
I used 3D face originally.

can always grab an edge and extrude/ stitch.

that’s what I do..

The trick is to pre-select the SubD you want to add to before running 3dFace, or to use the Append option. Then you can directly draw a face to add to your SubD, and have live mirrored feedback, and the face will be added to both sides of the symmetry directly. With the Mode=MultipleFaces option it ends up being pretty quick.

Bridge is also mostly symmetry-aware and can fill up some parts of that cap without losing the symmetry.

Whaaaat. Ok cool.
I would have never found out by mylself, to select the Subd Model first, before running the command…

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