… for Visual Effects

Tip #1778: Render After Effects Comps 70X Faster

Larry Jordan – LarryJordan.com

Even simple changes vastly affect render speeds.

This article, written by Chris Zwar, first appeared in ProVideoCoalition.com. This is a summary.

Render times in After Effects can vary a lot. If you’ve been using After Effects for a while, you’ve probably had some projects that render quickly, and others very slowly. Sometimes it can be hard to pinpoint exactly why some projects render faster than others.

At a very basic level, there are four things which determine how fast After Effects will render a single frame. Firstly, there’s the resolution of the composition. Secondly, there’s the resolution of each individual layer in the composition. Thirdly, there’s the number of layers in the composition. Finally, there’s the bit-depth of the composition – which determines how much data is required to process each individual pixel.

More recently, Adobe has added a fifth new variable – Multi-Frame Rendering. This is a new feature, still in Beta development, that utilizes more than one CPU core to render multiple frames of a composition at the same time. Depending on your hardware, rendering can be more than twice as fast.

The video [in this article] covers all of the details, but it’s probably worth emphasizing that this is a relatively niche demonstration. I didn’t try changing the overall composition resolution, and having 920 layers in a composition isn’t something you see every day. The project only uses one effect, and yet it’s a great example of how simple changes to bit-depth and resolution can dramatically affect the amount of data that After Effects has to process in order to produce a rendered image.

Here’s the link to the video and more details.