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I thought that for this article I would take a look at a great feature of After Effects that will help you in ways you might not even think of, and that is a Null Object.

Most people might not understand what a Null Object is because the definition of Null is "without value, effect, consequence, or significance", but as we, as graphic artists know sometimes nothing is really something.  Let's take a look at what I mean, and how you can use Null Objects to make your life easier.

First, let's launch After Effects and create a new composition.  We'll use a standard D1 720x486 comp size, but at the end of the day, it really doesn't matter what size comp you use, as the result will still be the same.  Next, let's create a new red solid to go in our composition.

Next, we are going to create a circle mask.

Now, one thing that is important for this demonstration is that our circle is in the middle of the screen, so I have added my "Rulers" to my composition window, I have put two guides in to show me the absolute middle of my composition, and have adjusted my mask so the circle is centered.

Now, I'm going to adjust the Anchor point of my masked circle, so the mask will move to the left, but its rotation point will still be in the center of the screen.

Now, I'm going to promote my Red Solid to a 3D layer, so I can rotate it on the "Z" axis, and then I'm going to duplicate my red, masked circle three times.  Once they're duplicated, I'm going to give them three different colors, and then I'm going to rotate them on the "Z" axis so that they are now located at North, South, East and West in my composition window.

Here's where things get interesting.  What I want is to have all my circles rotating around the center of my composition.  Most people, at this point, would start keyframing each layer's rotation values to create this type of effect.  That's way more work than you need to do, and this is where Null Objects come into play.  Let's create a new Null Object in our composition.  You can do this by navigating to LAYER>NEW>NULL OBJECT.

Once you let go of the mouse, you will see the layer appear in your timeline, and a "box" appear in your composition window.  Believe it or not, what you have actually done is created nothing.  You have created a layer that you can scale, rotate and even adjust it's position, but if you were to preview your composition, you wouldn't actually see anything.  What we are going to use our Null Object for is a "Parent" layer for our circles to rotate around.    To do this, select all your solids, and in the "Parent" section, we are going to select "Null 1" as our "Parent".

Now, to rotate all our circles around the Null Object, who's center point is located at the center of our composition, all we have to do is rotate our Null Object.  We can even add Motion Blur to our layers to give an even more realistic effect.

Null Objects are great tools that save you lots of time when it comes to creating complex animations in After Effects.  If there is anything you would like to know about After Effects or motion graphics in general, feel free to drop me a line at kevin@reelclever.com, and maybe your question will be the topic of my next article.