Tuesday, November 14, 2006

Click tracks and bar sheets

pointnclicked.jpgAsk most CG animators today what a bar sheet is or what a click track is and they’ll look at you with that slight head tilt furrowed brow look that dogs use. “Click what? A bar whos-it?”. i admit that I used to be the same way.

If you don’t know what a bar sheet is (or if you had read about them but you don’t know how to use them) or what a click track means, then you need to go get you some learnin’! Where to go to school about this stuff? Well, you need to run- not walk- over to Hans Perk’s blog. Hans has a gold mine of old bar sheets from some classic Disney short films. For a while now he’s been posting the bar sheets and explaining about how to read them, what they mean and what they were used for. Lately he’s also taken to re-creating click tracks and superimposing the results onto some Disney short films from the old days. You definitely need to check it out. (Through The Mirror and the classic The Pointer are now both posted with superimposed click tracks).

His conversation kinda assumes you have some basic exposure to bar sheets, though. I’d wager that most CG animators don’t have a flippin’ clue what he’s talking about. We’ve never used them or even seen them- or perhaps even heard of them. After the jump I’ll give all of us See-Gee kids a little primer on what this is all about….
What’s a bar sheet? Well in the land before scrubbable audio in CG application timelines and realtime story reel editing with Avids or Final Cut, animation directors needed to pre-time their short films with the music composers for the films. And like all things pre-digital this was done on paper. The director for the animated film would have a sense of the pacing of the action in a film figured out as beats per frames. For instance, a bar sheet might mark a section of the film as “2×12″. The 2 is the number of major beats for the measure, the 12 is how many frames for each beat. Thus a beat every 12 frames is 2 beats per second (24fps remember). This comes out to 120 beats per minute- a system of timing that translates into music language and can be marked out on a metronome. Bar sheets were the master document regarding the tempo for a film- what it was, how it changed, where it changed. It would have rows for describing the animation, another for sound FX another for dialog and another for the music. The bar sheet would mark out seconds of film and the composer would even write down and number every bar/measure for the music. Timing and tempo changes were all done on the bar sheet, cuts were determined on the bar sheet- the whole blinking cartoon was figured out on the bar sheet. And they did this all before they animated a single scene. How freakin’ genius is that?! This would give a timing structure to the animators as well as the musical composer. The animators would try to have major pose hits or actions occur “on beat” knowing that the music- whatever it may be- will also be sharing the same beat and timing. Scene cuts would happen on the beat or just before it to let the first accent of a new scene fall on a beat. The connection and harmony between the visual action on screen and the beats of the music played for the film would be immediate and very strong. A click track is just an audio marker system that the composer would use to listen to the beats for a film as they watched the story reel. This way they could hear the timing as they watched the story reel and get a sense for what the music needed to do there. When you watch a golden age animated cartoon with a click track superimposed you can actually SEE the animation hitting the beats as you hear it in the click track. It’s a huge, huge educational experience. The sense of connection and structure to the film, the link between the animation, the editing and the music is so strong- it’s almost darn near perfect. I’ve worked in CG animation for 13+ years in every imaginable form- commercials, short films, direct to video, TV, feature films, game cinematics- you name it. I can tell you from experience that hardly anybody in professional CG animation today even thinks about this stuff. Maybe somewhere somebody does, but I’ve never seen it or heard of it and I’ve been exposed to a lot of different systems and projects.

Today timing & tempo is not generally applied in a universal fashion for a film. The realtime editing paradigm allows endless noodling of cuts and individual animators are given no guiding sense of musical timing for actions (unless it’s a specific “song & dance” sequence). But a musical tempo for all other scenes in the film? Doesn’t happen. Today music for animated films is usually treated as another post process, done after the final animation and layered on top like icing on a cake. The sense of connection isn’t as strong though and what you often get is this mish-mash of music and animation that rarely play off of each other.

Anyhow, go to Hans’ blog and go to school. You’ll probably need to go over the stuff a few times before you get your head around it. But when you do get your brain wrapped around what’s going on and you realize just how incredible it is you’ll sit back in your chair and realize just how little we really know about animation on this side of the digital divide. I for one love the rediscovery of this stuff and I can’t wait to apply these things to my next short film project.

1 comment:

Keith Lango said...

original comments here..