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MIDI in Motion, Part 2Controlling multiple parameters and objects
One of the tremendous advantages of using MIDI in Apple's Motion 2 is that it can take a terribly difficult animation and make it into something simple to control. By way of example, I'm going to show you one way to use a MIDI keyboard to animate a fake 3D keyboard. But you don't have to be so literal about this. MIDI can be used to fly text around the screen, to change the colors/tints/shades of multiple objects at the same time, to control animatics in real time, etc., etc. It's useful for anything that requires you to keyframe multiple parameters simultaneously. It's just a great timesaver.
Now, this is the second installment in a series of articles about using MIDI in Motion 2. The first installment was an introduction to using MIDI in general. In it, we created and animated the white keys in a keyboard that has a somewhat 3D style. Now we move on to the much more difficult and complex process of adding in the black keys. It's tricky to set up, but the trick is more of a conceptual one than anything else. Here's the basic idea.
Before we get started, if you have not done so already, you'll want to go back and read part 1 of this series ("Tickling the Ivoroids in Apple Motion 2"http://www.creativemac.com/articles/viewarticle.jsp?id=35300) to get the basic concepts down and to set up the first half of the project. I also have some downloads for you at the following links.
? View the first part of the tutorial
? Download the first half of the project (8 KB zip file)
? Download the completed project (20 KB zip file)
Note: You should have your MIDI device turned on prior to launching this project in Motion.
Creating the basic keys
What makes the addition of black keys so difficult is that we're trying to convey the illusion of 3D in a 2D motion graphics program. This means we have to simulate the appearance of depth where none exists. And in the case of objects that, in the real world, invade one another's space in three dimensions, this means the use of masks that have to be animated. Using traditional keyframing techniques, this project would be prohibitive. But with a little thoughtful setup, we can use MIDI to make this task a breeze.
We'll begin, once again, with the creation of a single key, which we'll then duplicate to create our full (partial) keyboard. As with the creation of the white keys, the black keys will be simple rectangles created with the Rectangle tool. Draw one and position it over the existing white keys in your project as seen below. This key should be on the same layer as the white keys, but positioned at the top of the stacking order within the layer.
And then apply an Extrude effect to the rectangle, just as you did with the white keys. Now, I happened to have skimmed ahead in this tutorial, so I know we're going to need a lot of extrusion in order to make this work. The reason for this is that we're going to be applying masks to an object that has a live effect applied to it. Masks work kind of funkily with this live effect, and adding some extra depth to the object seems to fix up the problem. Here are the settings I'm using with this Extrude filter. (Note that I've used a gradient to color in the sides of the extrusion. You don't have to do this, but I think it helps convey the sense of 3D a bit better than strictly black sides.)
And here's how it looks at this moment.
Not too good.
So what we need to do is to add masks so that the black key appears properly in relation to the white keys. The first mask I'll add will be a rectangle on the right of the key to cover up some of the extrusion. I'm just using the Rectangle Mask tool to create this. (This mask uses the default Add blend mode.)
Note that I've had to position it in a weird place to get it to work correctly. That's just necessary when working with the live Extrude effect. If you want to render out your key first and then apply your masks, it will make the placement of the masks more intuitive and will give the key a sharper edge, but you'll lose the ability to alter the color of the key when it's depressed (which we'll get to below).
Related Keywords:apple motion 2, midi, midi behaviors, animating with midi, midi keyframes
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