Posted 07 Jul 2017

Synthetic stop-motion essentials

I love stop-motion. But I’m lazy. So making stop-motion films with After Effects – both quickly and easily – makes a lot of sense. So I made a class on it. It’s called Synthetic Stop-Motion in After Effects: Quick and Easy Techniques for Hand-made Animations. So here’s a few synthetic stop-motion principles, tips you should think about, issues, and expressions used in the class.

Synthetic stop-motion principles

Some tips

3D issues when using the Posterize Time effect

You can solve most of these issues by applying the Posterize Time effect on a precomp layer of your composition inside another composition, or use the posterizeTime expression.

Expressions used in the class

Expressions are amazing pieces of JavaScript code that you can write for layer properties in After Effects. Here are a few we use in the class:

Wiggle Expression

// wiggle(fps,amount);
wiggle(10, 20);

Wiggle X and Y only for a 3D layer’s position value

w = wiggle(10,5);
[w[0],w[1],transform.position[2]];

posterizeTime expression

// posterizeTime(fps);
posterizeTime(10);

Remember: this expression works only for a layer’s property, not the whole layer.

Short straw technique

// generate random number between 0 and 10
random_number = random(0,10);
posterizeTime(10);

// set short_straw to false by default
short_straw = false;

if (random_number > 9) {
  short_straw = true;
}

if (short_straw == true ) {
	wiggle(10,.2);
} else {
  lightOption.color;
}