UV Unwrapping In Sub-D Workflow Questions

wutwut

Hi guys, what should I do in this scenario for UV mapping? Say the model is being made for production, not games. Should I UV unwrap the high poly and texture it directly? I ask because in this case the shape of the low poly drastically differs from the high poly. And more in general I'd also like to know how UV unwrapping should be approached with a Sub-D workflow. It seems most people unwrap the low poly, but how can you possibly avoid UV's messing up between sub-D levels if the model's shape is completely different subdivided vs non-subdivided.
The image I've attached is a model I'm working on that showcases an example of what I mean. If I UV unwrap the low poly and texture that, it will look all messed up on the high poly since it goes from square to rounded ports (the holes in the top of the gun)

Neox

What do you mean with it is for production?

Just from the little context i see, i assume you mix up the terms lowpoly and basemesh?
So you wanna unwrap the basemesh, but preview that unwrap subdivided. Dependent on your smoothing algo, yes UVs might change between basemesh and subdivided mesh, in some cases drastically. This is something you need to be aware of and work around.
Open Subdiv btw has some ways to distort UVs less but really, you might just need some mote support loops around seams.
That the basemesh UVs and the smoothed ones are not identical is not an issue, just texture the subdivided model.

ZacD

Either model in a way that the subdiv doesn't have edges dramatically sliding around and stretching the UVs when smoothed
or
Subdivide once before UVing/texturing

wutwut

ZacD said:

Either model in a way that the subdiv doesn't have edges dramatically sliding around and stretching the UVs when smoothed
or
Subdivide once before UVing/texturing

Alright thanks.

Michael Knubben

If by production you mean animation/pre-rendered: Yes, you'll need to model in a way that things don't slide around much. This means much more evenly gridded meshes, less lowpoly. If games ever take the step towards realtime sub-d, we'll all need to learn what animation artists have been doing all along, as UV stretching/sliding is a concern there.