Join Chris Meyer for an in-depth discussion in this video Quizzler 1 solution: Touching wheels, part of After Effects Apprentice 09: Expressions.
Your first Quizzler challenge was how to hook up these various pulleys to make…them rotate as if they were actually all physically touching.…I'll show the quick-and-dirty way to make this happen and then a trickier way…of making it happen.…The first thing I need to know is what is the relative size of these different…pulleys? Since they all started from the same source layer, the clue is, how are they scaled?…I'm going to type Shift+S to review Scale for pulley 1.…It is scaled to 100%.…Select pulleys 2 and 3, press S, they're scaled to 50% and 25%.…
Well, the rule with things like gears and pulleys and tires all this other…stuff is that the relationship between your sizes exactly equals the…relationships between their speeds.…Smaller ones will rotate faster; bigger ones will rotate slower.…Now you could copy and paste keyframes and manually edit values, but we showed…you earlier in this lesson why that's a bad idea.…Let's use expressions.…Now before we hook up expressions, we need to actually reveal the parameters…
The After Effects Apprentice series was created by Trish and Chris Meyer. These tutorials are designed for After Effects CS4 through CC, and can be used on their own or as a companion to the Meyer's book, After Effects Apprentice.
- Creating and managing expressions
- Linking together different parameters
- Randomizing a layer's movement
- Looping an animation
- Controlling multiple layers from a single source