I can speak to this a little. Although our artists have standardized on Maya, I personally am much more comfortable in Blender, so have done a fair bit of work with UE4 and Blender.
Blender FBX support has, historically, not been very good. The FBS SDK that games and commercial applications use to import FBX can’t be used with Blender, even though it’s free, because the license terms are not compatible with Blender’s GPL. As a result, Blender support for FBX is custom-written and created by reverse-engineering the format. The FBX format changes a little every year, however, so it’s a moving target and they’re unlikely to ever have full FBX support of all features.
The last two Blender releases have seen huge steps forward in the stock FBX importer and exporter, and I’ve had quite a bit of success getting FBX files from Blender into Unreal using the stock exporter. What I haven’t been able to get working is the round trip - exporting from UE4, editing in Blender, and importing back into UE4. The importer only brings in the mesh, not the skeleton. I’ve had a little better luck with the third party FBX importer available at http://blenderfbx.render.jp (but only for Windows). With this, I can import the model, but after I export and try to bring into UE4, it won’t match the skeleton to the exported model. I think it’s because Blender is inserting an additional root bone on export, so the skeletons don’t match. I’ve tried working around it by modifying the export script to no include the extra bone, but the skeletons still don’t match.
If you’re not worried about round-tripping, though, you should be able to get very acceptable results with a little tweaking.
I find the best solution is to export two files - one with just the mesh and armature, but without the animations, and one with the armature but no mesh, but with the animations. UE4 likes to import the model/skeleton separately from the animations. I’ve gotten it to work by importing the same file twice, but exporting two files works better.
These are the settings I generally use for the mesh/skeleton export:
For the skeleton and animation export, I use these:
If you have more in your file than just the model, you should select the model you want to export in the 3D view and then check “Selected Objects” to make sure you’re only exporting the objects you want.
Be careful about “Apply Modifiers”, especially if you used a multi-resolution or subdivision surface modifier to generate a normal map. If you select this and have either of those modifiers in your stack, it will export a very high resolution model that’s not suitable for game use.
I hope this has helped.
