Our studio recently made the switch from 2015 -> 2016 and all appeared to be well until recently when I noticed about half of our skinned mesh props that featured blendshapes were failing to export with intact blendshape data. When imported into UE4 it recognizes the Morph Target node name and influences, but 0 verticies. Similarly, if I reimport the exported FBX it seems the Blendshape node and names, but if you increase the weights the mesh is unaffected.
In the past this has happened when the Blendshape targets weren't included in the the export set. However I've checked and the targets are definitely included in the export selection.
Initially I made some progress when I tested moving the location of the blendshape targets. In some rigs I include the mesh in the target rig, and in others I included it in the character file. I had 2 files that weren't exporting from blendshapes from 2016 (despite previously working in 2015) start working when I moved them to the rig file. I thought I had it solved, and that there was an issue with the data coming from a non-file reference (not sure why that would be, but its an easy enough fix) but now I've encountered a new prop file that did not return to working even after moving the blendshapes.
The pipeline here at the studio is to keep the mesh and rig in seperate files, then reference those 2 files in and skin only in a character file. Then that character file is referenced into animation files. That way I can skin many meshes to the same rig and replace reference to preview different characters all in maya. This means that the blendshapes are often created in the character file for ease of use.
Does anyone have an ideas what might be going on with 2016? We use the same scripts for export and the same files used to work in 2015. Did anything change in the python fbx settings api (since they added the new game export window that we aren't using)?
I'm currently stumped and as we many page and book based props that have extra blendshapes for detail deformations we've got work backing up that I can't export.
Thanks for reading, and I'd love to hear from any other 2015 -> 2016 converts that encountered any other problems. Besides this its been smooth sailing for us, the file profiling is great.