It may be possible that MikuMikuDance animation software can export its own projects (.pmm) as AVI videos for some kind of previewing purposes of the animations. This is probably the most convenient way how to achieve this particular pmm to avi conversions.
Convert MikuMikuDance PolygonMovieMaker file to Audio Video Interleave movie.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert pmm to avi on Windows
MikuMikuDance is free animation software used to create 3D animation movies. Popular in Japan.
Convert from pmm file
to avi file
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.