MMDs

MikuMikuDance (MMD) is a freeware 3D animation program and its associated model and motion formats that has become a popular platform for fan-made animations featuring Hatsune Miku and other Vocaloid characters. It allows users to import 3D models in PMD or PMX formats, manipulate bone structures to pose characters, and apply motion data in VMD format to create movement. Additional elements such as camera paths, lighting, physics, and accessories can be added to produce short clips suitable for sharing on video platforms.

Typical workflow: import a model, apply a motion data track, adjust timing and lip-sync via morphs, attach props, animate the camera, and render a video. The software's simplicity and focused toolset contributed to a large community of model designers, motion creators, and editors. Models and motions are widely shared on Nico Nico Douga, YouTube, and related communities, with many creators remixing or combining assets.

File ecosystem: PMD and PMX are model formats; VMD is motion data; VPD data exists for poses; textures are in common image formats. There are plugins and tools to convert between formats and to import/export to other 3D packages (for example Blender with MMD Tools).

Licensing and usage: many assets are distributed under permissive licenses for non-commercial use with attribution; commercial use requires consent from asset authors. Users should verify each asset's license.

Limitations: MMD's rendering engine is specialized and may not support advanced shading or heavy physics; compatibility across models and motions can vary; models can be polygon-heavy and require performance hardware.