[Bf-committers] unwrapping on subsurfed meshes

[Jean-Luc Peurière]

the UV mapping and the LSCM unwrap work very well for non subsurfed  
meshes.

however there is a slight problem with subsurfed ones, see http:// 
jlp.nerim.net/dev/unwrap-on-subd.jpg
on the left subsurfed at level 2, on the right the base mesh (control  
cage of subsurf).

As you see, the LSCM mapping produce very nice results, but get  
distorted when subsurfed. It is pretty
clear that distortions happens along relief of the mesh.

Imho, the main distortion is due to the fact that, when subsurfed,  
each control vertex is moved a different
amount in a different direction. newly created vertices can cause  
also problems if they define a curvy face,
but i think that taking in account the real position of the  
"original" vertices would solve most of the problem.

So, could we feed to the unwrapping process (LSCM but also others)  
not the original (control cage) pos of
vertices, but their final pos after surbsurf ? can we get this info  
from derived mesh ?

Another solution would be to apply the subsurf modifier then redo the  
LSCM, but infortunately, pinning info
is lost in the process. Besides, this is  also not very efficient as  
the model becomes heavy.

this problem affect also other tools (eg loop cuts) for the same  
reason, but on UV this is really unbearable

-- 
lukep