Hello,

I am trying to make a scene with many characters in UE4 that have a transparent object on their head. It looks great if I export using Auto-setup and assign the transparent object in UE4. But I need to use LODS with many characters on screen to keep performance usable. But when I export from iClone with 3 LODS...everything is merged into 1 texture. Then I am not able to assign a transparent material in Ue4 to that specific object. 

I have also tried exporting the skeletal mesh without the transparent object and then attaching that separate object to a bone in UE4. Unfortunately that does not seem to be compatible with my crowd plugin workflow (Atoms Crowd).

Does anyone have suggestions for solving this issue?

I don't use UE, but for a similar situation I would create an opacity map that's only has transparency for the area of the map that holds the texture for the specific object. 

So the map would be white except for that area. I would think though the system should do such things automatically.

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I was able to Merge Materials by Type and that creates a good compromise with quality/performance and giving me unique material access to make my accessory transparent in UE4. Now I just wish that feature would work with the LOD creation to automatically create 3 versions of decreasing quality using 3 merged materials. But InstaLOD seems to always create a single material for all objects...while making the Merge Material option unavailable.

Is there a way to combine these techniques? Or do I need to somehow apply my desired changes export....undo...and repeat? 

Thanks for the idea. I am able to set the opacity of this accessory in CC3 which does appear in UE4 (although it looks quite strange compared to the nice glass shader native to UE4).

I suppose my main goal is to export 3 models of decreasing quality that use the Merge Materials by Type so I retain unique material access to the accessory. 

Perhaps I have to do this manually instead of using the LOD export method? 

Hi fotsch,
Seem you want your transparent object can be alone to adjust. I suggest you using "by item" mode in LOD merge material , or you need to set your transparent object be the other type which you did not use.
Here is the manual, which is explaining about  the sort of type. For your reference.
 https://manual.reallusion.com/Character_Creator_3/ENU/3/Content/Character_Creator_3/3/17_Export/Merging_Materials.htm?Highlight=Merge