after effects expression linear position

One example I mention in the tutorial is an expression that automatically fades a layer up at the start. But it sets up basic variables and creates a counter (t) which starts at 0 at the beginning of the layer, and is clamped to the layer’s duration. This first expression is a basic frame counter for a layer. The tutorial demonstrates a few useful pieces of code, so here they are in a form you can copy & paste.

The point of the video tutorial is that all automatic animations need to be based on time. We often use the term “motion graphics designer”, but I often think that the “motion” is left out of the design part (this is the topic of an upcoming article…) While this tutorial is clearly about expressions, I’ve structured it around types of motion – linear motion, smooth motion, and so on. However I’d like to emphasise that the tutorial is demonstrating types of animation, and not just lines of JavaScript. Now that it’s 2018, I think expressions are much less divisive and I’ve chopped that bit out. In the original 2009 version of this tutorial, I spent a few minutes at the start apologising for making a tutorial about expressions and justifying why they are useful. Eventually, I uncovered a tutorial that I made in 2009 but never posted! It had been sitting in a dusty folder on an old drive for almost 10 years… I’m not completely sure why I didn’t post it, but I updated the graphics and edited the audio and here it is now. But I searched through all of my older articles and I couldn’t find anything. I was creating a graphic to illustrate what the modulo function did and I was sure that I had done this before. When I was working on an earlier article, demonstrating how I used maths to automatically animate a cake, I felt a strong sense of deja vu.

This video tutorial introduces the topic of how to automatically animate using expressions, demonstrating why it’s not quite as simple as you might think. Have you ever wished you could just press a button and have After Effects do all of the work for you? While we’re not quite at that stage yet, expressions in After Effects can go a long way to automating specific types of animation.

After effects expression linear position