Hey Victor, I'm aoakalin from GitHub that suggested the blend file stuff. I have tested the new change, and looks like we are very close to make this perfect. I have noticed three issues so far. Two of which I can definitely live with them; but the other needs a solution.
* Morphs were baked when I did a CC3 -> Blender -> CC3
* All Skingen data is baked when I did a CC3 -> Blender -> CC3
I believe those two are very difficult problems to tackle and probably won't worth your effort to fix, if they are even possible to fix anyways. I definitely can live with those two issues. Skin and makeup data can be saved as custom files and re-applied if necessary; and morphs can be baked negatively to revert them back. I'm very OK with such issues, I only need to change clothes and hair of the character anyways when I re-import to CC3 from Blender, so those problems are not even real problems, just wanted to mention so that anyone having them might find this thread easily when searching.
* Due to DRM protection, fbxkey file needs to be present to be able to re-import to CC3
OK, this issue has clearly nothing to do with you as this is how Reallusion created the workflow. However, this issue causes two problems that might need some workarounds that we should look for.
First one is, selecting "Mouth Open as Morph" is kinda a timesaver, but when chosen, CC3 does not generate fbxkey files alongside the output. Similarly, choosing the "Delete Hidden Faces" option does not generate fbxkey file as well.
I can definitely live without the mouth open combined morph, as it is possible to manually achieve that functionality; and also your Unity project has a good example to manipulate face, it can be done easily with scraping your code, so I'm fine with this issue as well. Here is how roundtrip plugin behaves without "Delete Hidden Faces" option (first is my base character, second is roundtrip version):
As you can see, I'm hiding part of the vambrace and shoulder mesh originally, and also hiding the bangs on the hair; but this data is lost on roundtrip. I believe due to DRM protection, even editing faces on Blender might not work; but I haven't tested this yet. Is there any way to keep the hidden meshes when exported to Blender? They are not hidden when exported to Blender either. Am I doing something wrong, or is this how it works and I should look for some workarounds?