My UV’s disappear when I subdivide a model, this happens with the Mudbox models as well as my own.

For example if I select Create >Mesh>Sphere, the UV’s show up in UV View then disappear when I subdivide.
If I export the subdivided model it doesn’t have any UV’s where the exported base mesh does.

Is it possible I’ve screwed up a program setting?

system = AMD Athlon 64 X2 Dual Core 4600+
OS = Win XP Pro
ram = 3G
Video card = Nvidia GeForce 9800 GT 1GB ram

this is the normal behavior…
uv needs much ram…
if you want your uvs back.... recreate them…

mesh --> recreate level uvs

http://www.linkedin.com/pub/christoph-schaedl/6/558/73b

Thanks oglu, that takes care of it.
I’m surprised that subdividing a sphere just once is causing me ram shortage issues.

Well it won’t probably. But it’s wasted memory if you don’t plan on painting on the model so it’s best left off if you just want a high res mesh to extract displacement or normal maps from. You can always Recreate UVs if you find you need them later (like if you want to bake AO).

If you try to paint on a model that you’ve subdivided without UVs it recreates them anyway, so no big deal really.

robinball 19 February 2009 05:45 PM

Well it won’t probably. But it’s wasted memory if you don’t plan on painting on the model so it’s best left off if you just want a high res mesh to extract displacement or normal maps from. You can always Recreate UVs if you find you need them later (like if you want to bake AO).

If you try to paint on a model that you’ve subdivided without UVs it recreates them anyway, so no big deal really.

Thanks for the additional info.

look at like this, each vertice has 3 points in space, with a UV, you add 2 additional points in 2d space.  In terms of memory, UVs will require 60% more memory.

Its not a lot of memory involved, but 60% can be significant when dealing with very hiResolution geometry.