What is a Multiplane?

A multiplane camera.

So maybe you've heard the term "mulitplane camera" before in your cruising of the animation world. But what is a multiplane camera and how has it had an impact on the world of animation?

Well when shooting traditional, hand drawn animation one of the final steps is to actually shoot your drawn frames. Generally speaking you'd use something called a downshooter, like this tiny diagram. Basically it's a camera that is pointing down towards a platform that you lay your pages or cels on and take pictures, real high tech stuff here folks.

For a long time that is how animation was done, placing your pieces of paper or cels on a flat surface and snapping a photo. Until around the early 30s when people started to experiment with what would become a standard in animation, the multiplane.

What a multiplane does is it takes your cels and backgrounds and separates them out from each other. This makes it so that instead of all your images resting right on top of each other there is some space between them.

Imagine dominos, without a multiplane every domino is pressed right up against each other, but with a multiplane we get the classic domino look of them with a little bit of space between each one. The traditional domino look is what the multiplane camera looks like. It's a camera held up and pointing down, similar to a down shooter, but there are multiple surfaces underneath it instead of just one.

It's like the difference between a table and a shelf, a table being the traditional downshooter and the shelf being the multiplane.

The top of the shelf is the camera, and each individual shelf is piece of glass with painting on it or a cel from our animation.

This technique allows for the filmmakers to control different elements individually from each other. That means things close up to the camera, foreground objects, can move faster than elements far away from the camera, background objects.

Imagine you're driving down the road at night and you are looking out your window. As you drive down the road, you'll have the street lights rushing past you like a blur, then you'll have the trees moving past you at a nice pace, then you'll have the moon looking like it's barely moving and almost holding still.

That's because, as I'm sure you know, the moon is further away from you than the trees, which are further away than the street lights, which makes it move more slowly in your vision.

A multiplane camera allows us to simulate this effect. For each frame we can move our streetlights a lot, our trees a little, and our moon barely any. If these were all stacked right on top of each other that would be much more difficult to get that effect, you'd have to pick up the stack and move stuff and try to realign it perfectly each time. Talk about a pain.

The multiplane allows it to move individual elements without effecting others, so we can move our street lights and trees without affecting the moon. Where it really comes in handy as well is allowing for realistic movement through Z space.

If we were to take a shot out the window of our car and wanted to simulate moving from the road into the forest and past the street lights, we'd run into a problem with our stacked animation cels.

If everything is flat on top of each other, when we go to move in we'd do so by lowering the camera closer towards the drawings. This would result in everything growing at the same rate, meaning our street lights would grow at the exact same speed and to the same amount that our moon would grow.

If we're moving through Z space we wouldn't see the moon grow unless we were in a rocket heading towards the moon, walking through the woods our distant to the moon isn't changing. Where the multiplane comes in is it solves this problem. We can move our street lights and trees up towards the camera without having to move our moon at all, giving us a much more realistic movement.

While Disney wasn't the first to use a mulitplane, former Disney animator Ub Iwerks actually revolutionized into what it is now know as, they were the first to really use it and take advantage of it.

Their first prominent example be the Silly Symphony short The Old Mill, but their most famous example is probably the beginning of Bambi, where we're moving through the forest. You can see different trees move at different rates, giving it an incredible feeling of depth.

Here's another neat example by Joe Peacock on Youtube where he breaks down a scene in Akira and shows the different layers used in the multiplane to create the desired effect, the opening of that video too is another great example of mutliplane so be sure to check it out!