This is a recurrent problem for me, sometimes I manage to fix it, but for some meshes nothing works...

I made new boots for my bodybuilder mesh, but no matter what I try I can't fix the infinitesimal slits appearing between parts mapped separately on my texture (using LithUnwrap). Although everything is regrouped I can't weld the vertices together, which shouldn't be a problem since they share the same assignments - but for some reason it shows on the animated sims.

Nothing obvious enough to clearly show on a pic, but still it seriously bugs me ...

Redoing everything almost from scratch (but after the uv-mapping) worked with my former boots mesh, but I have no idea what I did then that I didn't try for these ones!

Any idea would be welcome...

are you using any software?
sorry i have no clue what youre talking about

Sorry, I guess some precisions would be useful...

I'm using Milkshape with Wes_h's Body Chop plugins. I make the new parts separately as obj. files and uv-map them with LithUnwrap before importing them in the gmdc file, then i triplicate them, regroup one exemplary with each body group , assign everything to the same texture and assign the vertices to the skeleton.

I can totally admit that vertices with different uv-coordinates can't be welded, but vertices with the same position and the same joint assignments shouldn't move separately in game? And why does it work sometimes?