Animation Try #2: Glass Falls Over

I didn't do this by an example in the book. Tried to do it from my own imagination. It was really hard to copy the butterfly concepts here. It seemed like there was always some unforeseen glitch. It doesn't seem that easy to replicate from one document to another. I know there are flaws with this. The main challenge is working with backgrounds....getting something to stay static instead of go away when you add something new. Click on the image to see the animation.