Creating Trees in After Effects

A client came to me recently with a very interesting and challenging project. They wanted to create an instructional DVD and use as source the imagery that had already been created for the print campaign.

The predominant image was a leafy fall branch superimposed over a soft, billowy background. After some consultation, it was decided that I'd make the branch into a 3d tree, and use this 'world space' as the basis for the introduction.

I contemplated tackling the project in 3dsMax, and indeed spent a good deal of time modelling trees and playing around with shaders and textures and such. But in the end, I decided that it would tie into the print campaign best if I were to use the 'actual' imagery. I decided to tackle the project using ONLY After Effects.

Now as most of you know, AE is a "2.5d" application. The worldspace is 3d, but any imagery you have (discounting 3rd party applications such as Invigorator and such) is "flat". Much head scratching ensued, until I finally hit upon a technique that really sold "the look" that I was trying to achieve.

Take a look HERE to see what the fully rendered intro ended up looking like (MPEG4, h.264, 1:04, 7 megs) and then take a gander at THIS tutorial (QT, h264, 25:27 dur, 43.7 mb) that explains the technique in detail, plus walks you through the finished project.

NOTE: at 5:16 in the tut, there is a little editing jump. Cut out accidentally was the step where I changed all of the masks to 'subtract' mode.

In the tutorial I talk about how one can interactively control camera focus distance, and here are the instructions and the necessary expressions code so you can do it too (thanks Harry and Dan for whipping this one up!)

1) Make sure you've got a camera in your composition.
2) Create either a solid or a null and name it "focusControl" (note: you can name your solid when you create it, but to change a null you have to select it in your comp window and hit the 'enter' key. You can then type a new name for it.)
3) Make the solid/null a 3d object.
4) Apply this expression to the "Focus Distance" parameter of your camera:

length(thisComp.layer("focusControl").transform.position, toWorld([0,0,0]))

The camera will now focus wherever your null or solid happens to sit. This expression is golden when you're doing a lot of Depth of Field work.