Convert PMX to PMD

Older MikuMikuDance (MMD) releases, plugins, and model viewers may require PMD and reject PMX files. Converting the model can restore compatibility, but PMX features without PMD equivalents may be simplified or lost.

What the PMX format is

PMX is the newer native model format used by MMD and related tools. It stores mesh geometry, materials, bones, morphs, display frames, rigid bodies, joints, texture paths, vertex weights, and newer physics and deformation settings.

PMX files are commonly created or edited with PMX Editor, Blender using an MMD-compatible add-on, and other utilities in the MMD ecosystem. They are common in current downloadable MMD models and in character assets exported from 3D software.

What the PMD format is

PMD is MMD's original model format. It remains useful for older MMD versions, legacy plugins, lightweight viewers, and applications that implement only the original PMD specification.

PMD's main advantage is legacy compatibility, not feature coverage. It has older limits on model data, materials, morphs, bone assignments, physics, and text encoding. Use it when the target application specifically requires PMD or when an older workflow must be preserved.

How to convert PMX to PMD

1. Install PMX Editor from a reputable project or distribution source on Windows. Avoid unverified file-hosting mirrors.
2. Back up model.pmx and every texture directory before editing. PMX normally references external texture files instead of embedding them.
3. Open PMX Editor and choose File → Open, then select the PMX file.
4. Check the viewport and inspect the material, bone, morph, and rigid-body data for loading warnings or missing textures.
5. Use the version's PMD export command, usually under File → Save As or a PMD-specific save option. Select PMD in the format field when available; changing .pmx to .pmd in the filename does not convert the file.
6. Open the exported PMD in the intended legacy application and test textures, posing, facial morphs, toon shading, and physics. Keep the PMX file as the editable master.

PMX Editor is the most direct desktop option because it understands both MMD formats. Menu names and PMD export behavior vary between releases and translations, so use the format selector or export command rather than relying on an extension change.

Blender is an alternative when the model also needs mesh repair or other editing. Import the PMX with an MMD-compatible add-on and use an exporter that explicitly supports PMD. Generic OBJ and FBX exporters do not preserve MMD bones, morphs, rigid bodies, or joints as a functional PMD file.

There is no generally reliable, mainstream online service for PMX-to-PMD conversion. Use an online converter only when it explicitly lists both formats, explains how it handles textures, bones, morphs, and physics, and permits uploading the model under its license and privacy terms. Generic 3D conversion sites commonly omit MMD-specific data.

Quality and compatibility limits

Conversion is usually lossy. PMX-only or extended features such as additional UV channels, QDEF weighting, some extended morph types, extra bone behavior, and newer physics settings may be removed or rewritten. The exact result depends on the model and PMX Editor version.

PMD also uses older field sizes and text-encoding rules. Long names, unsupported characters, material or morph data, and certain bone settings may be truncated, rejected, or rewritten during export. A file opening successfully does not prove that its expressions, deformation, or physics remain correct.

Preserve texture filenames and relative folder paths. A PMD can open without errors while appearing untextured if its image paths changed or the target program cannot read the referenced image format.