Expressions cookbook

Every expression here compiles in After Effects' JavaScript engine (the default since AE 16). Apply one with ae_set_expression: After Effects validates it on the way in, and if it doesn't compile the error comes back and nothing is left attached. Use layers to apply it to many layers in one undo step.

ae_set_expression {"layers": {"match": "^Dot"}, "path": ["Transform","Position"],
                   "expression": "wiggle(2, 20)"}

Before writing one, check what's already there: ae_find_animation lists every expression, with an expressionError field on any that's broken.

What you can and cannot say