Understanding the order of how things happen is important when using Adobe After Effects. The order of filters in the effects window, for example, noise and blur, determine the results of filtering an image. Even more fundamental is the "Rendering Pipeline." The pipeline's job is to process your raw footage into a final movie through the mask, effect, geometric and transfer controls settings.

This poses a challenge, for example, when applying a time based filter like Echo to an animated still. In this case Echo composites information from other places in time, but doesn't have that information because position is calculated after effects. The order of rendering pipeline cannot be changed, but Composition Nesting (using a composition as a layer) and the Pre-compose command (sending current layers to newly created comps in the past) let us work within rendering pipeline constraints.

In this exercise we will explore "how things happen" when using the Basic 3D filter to simulate opening a door. Doors open on hinges, but AE spins layers on their anchor point, which is centered by default. Changing the anchor point in this composition will not help us because that change will be seen after the 3D move. In this case Composition Nesting is required.

We'll look at the problem and at few "long way" approaches, and then at a few approaches with a shorter number of steps. If you follow the links below, you should acquire a basic understanding of both anchor points and the rendering pipeline. You could go directly to the better ways but looking at the difficulties will help keep you on your feet.