Thanks a lot! I would love your help! I guess you work with a transparency map? Take the normal and black/white it? :)
Daz3d uses "transparency maps" to cause transparency. All eyelash texture files have a "transparency map" associated with them. These maps are black and white image files that tell Daz3d what part of the eyelash needs to be transparent. All the areas marked in black on the transparency maps will appear transparent in Daz3d.
Unity uses PNG transparency, so just open the eyelash texture map in Photoshop/Gimp, then place the transparency file on a layer above it and use it as a guide to cut out the eyelashes. Or just cut the eyelashes out manually with the transparency map as a guide. You can also do this to hair and clothing that have transparency and etc.
If you don't have Gimp/Photoshop you can try using this old eyelash texture file. It's not perfect but it should work on most current Daz models.
