Hi. If you were to look through the catalog, you'd find no maxis mesh that has sculpted deep folds like yours, all of them are painted on the texture. The reason for this is that folds would move and morph weirdly. Using transparency with them adds another problem, Z-sorting.
In the picture below you can see the transparency issue and how jagged the folds look when they move
Since your mesh is made in a way it shouldnt be, you'll have a very hard time making it work, so I'd advice to not waste your time on this
You have to re-do the whole thing. Read it first to know what expects you, especially in the end, fixing the transparency issue is a very tedious process:
- join both meshgroups together again;
- select one body parts, press Ctrl L to select all of them, Delete - Faces so that only the skirt remains;
- simply triangulating the mesh does not seem to work with s4s, you need to re-import it. With this meshgroup selected, File - Export - Wavefront ( obj), enable Selected only and
Triangulate mesh;
- clone yfBottom_EF11SkirtPencil, export the blend, open. Select the skirt itself, rename this meshgroup to Reference, delete the other two;
- import your skirt;
- add Data transfer, transfer weights, uv_1 and vertex paint from the reference to the skirt,
apply the modifier, then Limit total and rename UVmap;
- under the rig, make bottom visible and selectable, select it, in 3d view press Shift D, then Esc to duplicate. Hide the original and delete the reference;
- in Edit mode enable X-ray, select everything with A, Mesh - Merge - By distance, select and delete everything covered by the underskirt;
- in this order: select bottom.001, ctrl-select the skirt, join;
- for the mesh to be see-through, its uvs must be away from the skin texture. So move uvs of the transparent part in the extra area, while the opaque ones can stay where the body used to be unwrapped;
- give the skirt cut 0000, save. Filter catalog by Bottom and 1 meshgroup, clone some skirt, import your blend, test how the mesh moves and morphs. If there are any problems, you need to fix them before baking textures or splitting the mesh;
- once happy, bake textures;
- now you can select the see-through parts uvs and separate the mesh into a new meshgroup with P - Selection;
- how the material is set up in blender does not translate to ts4, but it will help you manually sort the mesh. Set up the material as
shown in the second section, split it in pieces,
join in the right order, remove doubles.
- give the underskirt+legs cut 0000 and 0001 to the see-through part, save;
- in the warehouse duplicate the first two geometries, changing their group numbers and shaders. Add them in Region map and LODs. Import your blend again.
