The Three.js Blender exporter has been broken for at least the last 10 releases of Three.js. It's had at least 20 individual authors and contributors, most of whom have left the project never to return. Nevertheless, I have successfully imported animated (both with rigging and morph target) meshes into Three.js. Here's all the things I've encountered which you need to know about:
- The exporter flips all vertices, faces, etc in the mesh you export. There used to be a "Flip Y/Z" option in the exporter, but it was removed when the exporter was rewritten. Since then speculation is the Blender API changed, or some other change after this one mangled the faces on export. For now we're stuck with it until we track it down.
- mrdoob/three.js#8723 Invalid json is exported for all files with animations, so you have to delete a key manually from the json
- mrdoob/three.js#8710 morph target exporting doesn't work with "a