Join Deke McClelland for an in-depth discussion in this video Understanding how the ball moves, part of Designing and Animating a Mind-Bending Illusion.
Now, one of the most important elements of any animation is motion. And, in our case, it's really the only important element, because all we have is a circle, a gradient circle, moving around a triangle. Thing is, it's an impossible triangle, and any time that you're dealing with an optical illusion, you really have to understand what in the world is going on. So in this chapter, we're going to plot the motion of the ball, which means we need to understand what that motion looks like.
So, notice how it's wrapping around to the top of the ball right there, then to the side, then down, up and around again, and then it goes ahead and repeats that motion over and over. So, we'll see it again in just a moment, there is position one, there is position two, three, four, and five, and then, it's repeating that motion around the other edges of the triangle. So let's see what that looks like inside of Illustrator. I'll go ahead and switch over to that program, and you can see that I've got this diagram file opened, with the ball in its very first position, and a label of one.
Now you can see that I've got several layers inside of this file, most of which are turned off currently. I'll go ahead and turn on position two, so you can see that, that is the first movement. So the ball moves down the side of the triangle, down and to the right. And then we've got this third position right here, so the ball moves from position two to three. But as it does so it moves behind this edge right there. Now to understand the next position we need to go ahead and turn off the first two, and then we'll turn on these two layers here so that we can see as the ball moves from position three to position four, it does so behind the triangle.
And then we see the top of the ball in the background. And then finally, as we move to position five, we continue to see just the top of the ball there, and then the ball emerges right there at its fifth position. And then after we complete that motion, we'll take it and we'll rotate is 120 degrees to create the next pass and another 120 degrees to create the final pass at which point the ball will once again arrive at position number one. So to see what that looks like without all the motion trails, I'll go ahead and turn off all of these layers here and then turn on the top layer which is called the five positions.
So you can see the ball starts right here at position one, it moves to two, it moves the three, then up to four, and then down to five. And then, of course, as I say, we'll duplicate that motion by rotating it 120 degrees two more times before we come back to position number one. Now of course, during this motion as we saw just a moment ago, the ball ends up moving once we go to position three up to four and then to five it ends up moving behind the triangle. For the time being, inside Illustrator, we're not worried about it.
We'll be addressing that issue in a later chapter inside Photoshop. And that friends, is the path of motion that we'll be plotting inside of Illustrator over the course of this chapter.
- Creating an "impossible" triangle with hexagons and gradients
- Drawing and filling the golden ball
- Drawing the path of the ball
- Creating frames as layers
- Animating your artwork in Photoshop