Based on my experiments with animated people generated on mixamo, there are four key elements to creating a file in Blender that can be exported to MSFS: (1) correct scale, (2) correct rotation, (3) save animation as an NLA track, and (4) store the default T-pose as a default NLA track. Here are the detailed steps:
Correct Scale
If you are uploading a model to mixamo:
- Scale your Tpose object to the correct final size and Apply All Transforms in Blender before exporting as an Obj file.
- Import the Obj file into mixamo and process into an animated model.
- Export FBX file from mixamo.
- Import FBX file into Blender with Scale=100, "Use Pre/Post Rotation", and "Ignore Leaf Bones" checked. This should ensure that the scale of the armature and the mesh match.
If you are working with a stock mixamo model, you will have to experiment with scale a bit. The mesh on some of the underlying models are 100 times the scale of the armature, in which case you should do this:
- Export FBX file from mixamo.
- Import FBX file into Blender with Scale=1, "Use Pre/Post Rotation", and "Ignore Leaf Bones" checked.
- Once loaded into Blender, you will need to adjust the scale of the mesh to 0.01 in addition to adjusting the rotation in the next step. The key is to make sure that the scale and rotation of the armature and mesh match after the Parent/Child relationship is severed.
Correct Rotation (and scale)
- Select the mesh, then in the Object Properties, under Relations, click the X to break the Parent relationship to the Armature (the mesh will now look really bad).
- Select the mesh and change its X Rotation to 90 degrees (the mesh should look okay again). Adjust scale of the mesh if needed (see previous step).
Save Animation as NLA Track
- Open the Nonlinear Animation tool.
- Rename the action strip to the name of your animation in your XML file; e.g., "aliendance".
- Click the button to "Push Down" the action to a track.
- Rename the track to match the action strip; e.g., "aliendance".
Create Default State
- Switch to the Timeline tool and set the frame to zero.
- Select the Armature and switch to Pose Mode.
- Select the Armature and click Pose / Clear Transform / All (model should now be in T-pose).
- Type "i" for Insert Keyframe and select "Location, Rotation & Scale".
- Advance Timeline to frame 1 (model should still be in T-pose).
- Type "i" for Insert Keyframe and select "Location, Rotation & Scale".
- Advance Timeline to frame 2 (model should still be in T-pose).
- Type "i" for Insert Keyframe and select "Location, Rotation & Scale".
- Switch to the Nonlinear Animation tool.
- Rename new action strip "Default_State".
- Click the button to "Push Down" the action to a track.
- Rename the track "Default_State".
- Make sure that the Default_State track is listed above the animation track in the Nonlinear Amination tool.
Apply Materials and Export
- Switch back to Object Mode.
- Apply materials to the mesh as needed.
- Select All.
- Export to MSFS. For structure of MSFS project and XML configuration, see example files linked above.