Matching UV mapping across objects

So suppose I have 2 objects something like this (highly simplified example) where I’m trying to set up UV mapping, which I am a novice at. I want the texture to simply flow across both surfaces as if they were part of a single surface. What is the best way to achieve that, i.e. is there an easier approach than brute-force manually trying to freehand scale and align (and bend, in the the real models, it can be a real pain) the island for the smaller surface within the larger one?

In your screenshot the inner surface appears to be a trimmed version of the larger surface.

As long as you don’t shrink the trimmed surface, the underlying UV coordinates will be identical and you can simply match the UV surface settings to the second surface and texture mapping will match.

That’s sort of the case at this level, but the bigger surface is part of a large polysurface.

But would it work to connect these up with temporary surfaces, map, then extract…?

Yeah it looks like I can add surfaces to join them up, then extract those and each object will have the same mapping, which may not be super efficient…but whatever.

Native UV mapping on polysurfaces is tricky.

(Look up packing texture coordinates)

Why don’t you just use normal mapping projectors,

Like planar, box etc.

Or a custom object if necessary?

Hi @JimCarruthers

I would first do a cylindrical mapping on the larger shape
than select the smaller middle shape and use match with the following options
see image.

RM