PMX to FBX converter: MMD into an engine
Zip the .pmx or .pmd with its texture folder and drop the zip. Out comes one binary FBX with the skeleton under its Japanese names, the morphs as shape keys and the textures embedded.
What comes across, and what cannot
Comes across
- · The skeleton, with the Japanese bone names as the author wrote them
- · Skin weights
- · Morphs, as shape keys under their names
- · Textures, embedded in the FBX
Does not
- · Physics: rigid bodies and joints are MMD's own and have no FBX form
- · Sphere maps and toon ramps: the materials arrive as plain PBR
- · VMD motions: they are not in the model file
How to convert PMX to FBX
- Zip the model folder as distributed, with the .pmx and its tex directory, and drop the zip. Up to 100 MB.
- The model is read on our server and written as a binary FBX with its textures inside.
- Preview the FBX in the browser, download it. Both files are deleted 3 days later.
The D-bones
MMD rigs usually carry two sets of leg bones: 左足 and 右足, which motions drive, and 左足D and 右足D, which the mesh is weighted to and which follow the first set through constraints inside MMD. The FBX keeps both, but no constraint comes with it, so in an engine the mesh follows the D-bones. Animate those, or parent the D-bones under the plain ones in your 3D tool, and the legs move.
Where the FBX goes
Unity, Unreal, Maya and Blender open it with the textures bound. For VTubing apps the right target is VRM, not FBX: the MMD to VRM converter reads the same zip.
Questions
What do I upload?
A zip of the model folder: the .pmx and its textures. The .pmx alone converts to a grey model.
Are the Japanese bone names kept?
Yes, exactly as the author wrote them.
Do the morphs come through?
Yes, as shape keys with their names.
Why does the leg mesh not follow when I rotate 左足?
Because the mesh is weighted to 左足D. Animate the D-bones, or parent them under the plain bones.
Can I play VMD motions on the FBX?
Not directly; VMD is MMD's own format. Convert the motion in a tool that reads VMD, or use the VRM route and a VRMA.
May I convert a model I downloaded?
Only if its terms allow it; many MMD authors forbid conversion.
For VTubing, make a VRM instead
The MMD to VRM converter reads the same zip and writes an avatar with the bones mapped and the morphs as expressions.