Join Chris Meyer for an in-depth discussion in this video Overview of Calculations, part of After Effects: Insight into Effects.
Calculations, it sounds really geeky, doesn't it? Well, indeed some of the geekier Photoshop users out there who like to do channel operations will feel right at home with the Calculations plug-in. However, you should think of it as your Swiss Army Knife effect, that can do same things as Channels, as Blend, as CC Composite, as many other effects. In this movie, I'll give you an overview of some of the things that Calculations can do, it's really flexible, and then in the next movie I'll show you how Calculations can help you do creative applications, such as the Filmic Glow and the adding lighting effects in post tricks that we have shown in other courses. So let's jump in.
I am going to use Calculations on this radio object, which happens to have an interesting Alpha channel. This will show up some of the Calculation's other features. Now Calculations is a compound plug-in, which means it has ability to look at a second layer. In this case, my second layer is a full frame piece of D1 footage. To make this work right, I really needed my radio to be the exact same size as my second layer. So to do that, I positioned it in its own precomp that was the same size NTSC D1. As the second layer I'm going later be using with this radio, positioned it, scale it the way I like. In that way in my main composition, my radio and my second layer both have the same size, okay.
I got my radio selected and apply Effect > Channel > Calculations. Several things you can do with it. First off, you can use it just to process this single layer. One thing you can do is a very quick Gray Scale effect. There is a gray version. You can also pick different color channels, like Red, Green and Blue to provide different gray scale versions of this image and again you can also invert it to create some sort of x-ray sort of looks and we'll go back RGB for now.
The other thing you can do is you can pick a second source. For example, White Puffy Clouds and I can blend in those clouds. Now normally, I'm going to get those clouds filling the Alpha Channel of my layer that I have applied Calculations to. If I don't want that, I can turn off Preserve Transparency. Now, I'm just fading between the radio layer and my second layer, which is filling up the full channel. There we go. If I do want to use this Preserve Transparency to where the clouds, my second layer, is filling the radio, you might have notice that I have got some edge artifacts going on around here. Well to cure the edge artifact, change the blending mode from Normal to Copy. That takes a nice, clean version of the alpha for my original layer, Calculations, and imposes upon my second layer. It looks much better.
Now there are other blend modes as well. For example, rather than having the clouds fill this radio, I can go ahead and say let's go ahead and use a blending mode to mix them together. For example, Overlay mode and now it has interesting effect of the clouds filling the radio, cropped by the radios alpha, but using the blending mode to put them together. This would take some thought to make this work out on the normal composition stack. In addition to using the full RGB color of my second layer, I can pick just a Gray Scale version of it and again any individual color channel to get different sort of blends. I'll go back to RGB.
So you can see it provides interesting ways to use one effect to blend together two different layers, including the ability to mix them using different blending modes, such as Hard Light, Linear Light, Soft Light and have some control over how they work and whether or not you use the Alpha channel when you blend these together. So, that gives you a feeling for some of the channel operations possibilities of Calculations. In the next movie, I'll show you how to use Calculations to achieve some of my favorite creative effects that blend together multiple layers.
After Effects gurus Chris and Trish Meyer share their real-world insight into how to get the most out of the effects that come bundled with this popular software. After Effects: Insight into Effects covers their favorite effects, hidden gems, optimal parameter ranges, "gotchas" to avoid, and alternative effects to consider. Among other tidbits, this course also contains "special topic" movies that pertain to more than one effect, demonstrate how to use After Effects more efficiently, and compare different effects to try in order to achieve a desired creative result. After Effects: Insight into Effects is recommended for all After Effects users, regardless of which version they use. This ongoing series that will be updated with new movies on a regular basis.
This course was recorded using After Effects CS4, but it contains many timeless concepts and effects. After Effects: Insight into Effects is recommended for all After Effects users, regardless of which version they use. This is an ongoing series that will be updated with new movies on a regular basis.