Problem fixing an UV face of an object with Multires modifier

[MithrilMan]

the problem is with the shackle:

To fix that face stretch I can just create a link between 2 vertex as shown here

But if I alter the mash of the shackle, that contains a Multires modifier, my sculpted shake got corrupted, see

first (original, without the new edge):

after, with the new edge to fix the UV stretch:

I didn’t heard about this problem in the lesson (I’m using blender 2.91) and I’d like to know how to fix these kind of problems on an object with multires modifier, without ruining sculpted details

thanks

[FedPete]

I would say, re-bake the normal map.

[MithrilMan]

I didn’t baked anything and normals are fine (I tried to look with “Face Orientation” option)
the problem is that I have to alter the base shape of a multires object while preserving the sculted details and it seems it’s not possible, at least for me.
Any instructor that I can mention in the forum?

[FedPete]

If you model the High resolution and decide to change the low model. How does the high model know your intention? So, sculpt the high resolution on that particular part?

[Jaco_Pretorius]

@MithrilMan

I’d like to know how to fix these kind of problems on an object with multires modifier, without ruining sculpted details

Afraid there is no easy way since the multires modifier exists on the base-mesh… in other words, altering the base-mesh has a destructive effect on the multirez data, as you’ve experienced.

Solutions:

• Just don’t add the edge… live with the stretch, its on such a small part no one will notice (my favorite solution)
• Go in again with a draw and smooth brush and fix it up manually.
• (I don’t like this one) Apply the multires modifier and retopologise.

So yeah, that’s just the nature of the multires modifier… you’re limited to some extent by the topology of your base-mesh.

Hope that helps.