Animating to the beat

I’m working on an animated music video.  I thought I’d share a bit of simple maths to help get footsteps on the beat.

bpm / 60 = beats per second
FPS / beats per second = frames per Beat

So if the song is at 150 bpm this would would be

150 / 60 = 2.5 beats per second

PAL is 25 fps so…

25 / 2.5 = 10 frames per Beat

Bear in mind that whilst most dance tunes have a computerized fixed tempo. Folk and jazz will mostly likely vary in tempo.

I have a tap tempo app for my iPhone that I’m using to calculate Bpm. I just tap along to the song and watch the bpm display. For the tune I’m working on there is a slow but steady increase from 150 bpm at the start to 160 bpm at the end.

3dsMAX motion capture utility

For more complex interactions or changes in tempo you might try and use the motion capture utility. This allows you to wire MIDI inputs to a Motion Capture animation controller.