Hair Mesh Not Appearing In CAS

Hi. Joining meshes was the problem. Check this thread sims4studio.com/thread/134/mini-tutorial-sims-hair-components
If you are modifying alpha hair, it’s best to not start from this, it is made of 6 meshgroups, you might have a hard time understanding why

Also, there is an addon called Multiedit that allows you to edit multiple meshes at the same time

Usually, alpha creators make hairs with 6 meshgroups to avoid transparency issues. The creator of the mesh you need managed to deal with those issues without extra meshgroups, it depends on how the mesh is made.

As explained in the linked tutorial, the hair package has a base shape(what you see when a sim is not wearing a hat) and two hat chops( what you see when a sim is wearing different types of hats).
In the warehouse they exist in this order: hat chop, hat chop, the base shape.
When you export these meshes as a blend file, they get cut numbers 0000, 0001, 0002 respectively.
Whatever you import back with the cut number 0000 will replace the first mesh(a hat chop) in the package, 0001 (a hat chop) will replace the second, and 0002 the third (the base shape).

When you join meshes with different cut numbers, the resulting mesh gets the cut number of the last selected one. In your current case, the last selected one was a hat chop, so you are not seeing the result in CAS (because you need to put a hat on). In the previous case, the last selected one was a base shape, so you could see it. But if you will put on a hat, the hair will go back to the original, because hat chops were not replaced.


Anyway, do it like this:
- open the original hair package, export blend files for all lods;
- open lod0 blend file, File - Save as, name it "progress" or something;
- rename each s4studio_mesh_ to its lod and the last digit of the cut number. So it should be lod0_0, lod0_1, lod0_2;
- File - Append - lod1 - object - shift-select all s4studio_mesh_ - Append from library;
- rename s4studio_mesh_ to lod1_0, lod1_1, lod1_2;
- do the same for lod2-3 until you have 12 meshgroups in the file. Delete rig.00x, so that only the original rig remains. Delete all bone_bone_shape.001;
- click on Code and choose download zip, put the archived file on your desktop;
- open blender, File - User Preferences - Install from file, choose the archived file, tick the new addon to enable it;
- now select all meshgroups and click on Multiedit enter;
- do what you need to do. This way you can edit all meshgroups of all lods at the save time without having to re-do the process for each;
- once you're done, click on Multiedit exit;
- the cut numbers are not preserved, so you should change them to the corresponding ones. Save the file;
- open lod0 file, delete all s4studio_mesh_, append lod0_0-2 from the progress.blend. No need to rename anything, just save;
- repeat for all lods;
- import them in the package