The Visual Effects Arsenal

VFX Solutions for the Independent Filmmaker

Bill Byrne

• Publisher: Routledge
• Year: 2012
• Print ISBN: 9781138474260
• eBook ISBN: 9781136137976
• Topic: Media & Performing Arts
• Subtopic: Film & Video

Build your VFX arsenal with quick-access, step-by-step instruction on how to create today's hottest digital VFX shots. This essential toolkit provides techniques for creating effects seen in movies such as 300, Spiderman 3, Predator and others, with lessons on how-to: * splatter blood or digitally lop someone's arm off * create a scene with actors running from an explosion * create the "twin effect" (same actor, same location, 2 performances) * produce space-ship dog fights Organized in a 'cookbook' style, this allows you to reference a certain effect in the index and immediately access concise instructions to create that effect. Techniques are demonstrated in each of the most popular software tools- After Effects, Final Cut Studio, Photoshop, and Combustion are all covered. Brilliant, 4-color presentation provides inspiration and stimulating visual guidance to the lessons presented, while the downloadable resources contain project media files enabling you to put concepts learned into immediate practice.

1

HOW TO USE THIS BOOK

When I teach classes in visual effects, I made an observation about what motivates students to learn. As I lay out to them what they will learn in my class, they don’t get excited about terms such as fractal noise, rotoscoping , and particle systems. Why would they, unless they know what those things can do for them?

When I teach my lessons, it’s not the tool they get excited about, it’s what the tool can do for them. So, I realized what is the problem in teaching software. Too often students are taught how to use a piece of software without being taught what to do with the software.

This book does not teach readers how to use the software. This book is meant for people who have a solid understanding of Adobe After Effects or something like After Effects, a nonlinear editing software and Adobe Photoshop. What this book does teach is technique. I gathered the material and lessons here to be a compendium of problems solved.

Most of the time, students who wait until class is over don’t wait to ask me about the inner workings of motion tracking , they are waiting to ask me “ How do I create an explosion?” or “ How do I make it rain?”

Often they can go Google a tutorial, which is not a bad approach; I often do that to see if there’s a technique I did not know about. However, there are tons of Web-based tutorials out there; many of them are top quality, such as the great material on Creative Cow (creativecow.net) or Video Co-Pilot (videocopilot.net). Often though, you will run into a tutorial that is too old, poorly or incomprehensibly written, or simply doesn’t work.

I decided to go through my own techniques, ones I’ve gathered from years of reading on the Web and things I have been taught and put together a collection of problem-solving techniques for a large variety of visual effects. I tried to cover as broad of a range of issues that could be solved with common, off-the-shelf software without expensive third-party plug-ins. I also decided that it was important not to focus on a single application but rather to teach the techniques and how something similar can be achieved cross-platform.

In many cases if there’s a silver-bullet absolute method to doing something, that’s what I demonstrate. In most cases, I am sharing the best technique I have found for something, which may change or you may find another method that works better for you.

The most important thing about learning to use any piece of software is this: learn the techniques first, they don’t change. Students and even pros are often very nervous about putting a ton of time into learning software, thinking, “ what happens when there’s a new piece of software that becomes the industry standard, what will I do then?” If you know the core techniques of your field, then learning another piece of software is much easier.

Look at it this way, let’s say that tomorrow someone introduces a new raster-based image editor and Photoshop becomes obsolete. This is very unlikely, as no one has been able to remotely compete with Photoshop, but let’s just say this for argument’s sake. Since most people have been using Photoshop, all the same questions you would likely have will be applicable to most users, so therefore the new software would have to meet the capabilities of Photoshop. So essentially, it’s the same set of capabilites, the buttons would just be in different places.

In fact, something like this is going on right now. Apple’s Shake looks like it will be discontinued at some point. So while researching this book, I stumbled upon many guides to users about how you would switch from Shake to Eyeon Fusion or Nuke.

The overall point I’m trying to make here is this: the techniques have a longer shelf life than software, and as software moves very quickly, the techniques will more than likely be the same for a very long time. Most of the techniques discussed in this book have been around longer than computers themselves. The computer has only been implemented because it’s a faster, easier way of pulling off these effects.

Sections

Each tutorial is broken up into sections; some will appear in every tutorial, whereas others will appear where appropriate. I wanted to treat these tutorials like recipes, as there are lots of similarities between the two.

Ingredients — These are what you will need to create your version of this technique should you need a special kind of footage or prop. In some cases I will recommend that you use elements created from another tutorial.

The Shoot — In this section you’ll get some quick advice on things to look out for during the shoot or ways to advise the director of photography.

The Design —Consider this to be the Photoshop section. It will discuss preparing the needed elements for an effect in Photoshop. As you will see throughout this book, you can’t underestimate the importantance of using Photoshop just because it’s not meant for working with moving footage. It’s one of the most powerful tools we have.

The Effect — This is the heart of each tutorial; each of these will be done in Adobe After Effects. I’ll go through all the techniques for using this software to solve the major issues of visual effects. Even though After Effects is a very basic compositer, I decided to focus on After Effects because of its market share. If most users have a piece of visual effects software already, it is probably After Effects. In most cases, for young filmmakers the cost of Nuke or Fusion is too crippling to a budget to make it feasible.

The Options —The effects techniques in this book are mostly cross-platform, and I will show you the same or similar technique and how to achieve it in an editing software package (Final Cut Pro), another motion graphics package (Motion), or a basic compositing package (Combustion).

Visual effects

Visual effects are processes used to manipulate imagery in the now mostly digital postproduction process. Often abbreviated as VFX, visual effects have taken over creating the kinds of imagery that were once dominated by the process of creating special effects. Special effects are effects either created on the set or within the camera.

Both of these processes are employed to take advantage of technology to make imagery that is impossible to find in the real world or far too difficult, dangerous, or expensive to achieve without the use of visual or special effects.

Before the 1990s there were two major special effects categories. Optical effects are techniques such as multiple exposures, glass shots, or mattes.

Also in this category were the effects achieved through the optical printer, where footage could be rephotographed. Optical printing effects are the basis for the software-based effects of today. The second category is mechanical effects , which are effects created on set, in front of the camera, such as with models, props, and make-up.

In the late 1980s, digital compositing emerged. Compositing is the act of combining two different imagery sources; a process that was once done on an optical printer is now enhanced with the greater control allowed by computers, at a greatly reduced cost. The early 1990s saw the beginning of wide usage of what is commonly referred to as CGI or CG. CGI or computer-generated imagery combines the process of animation with the use of photorealistic textures to create characters, scenery, and whatever else the mind can imagine to create what cannot be shot.

In today’s visual effects world, two major sets of techniques are used to solve most issues. Can the shot a director needs be achieved by generating graphics, combining different sources of footage, or employing both processes?

Digital Compositing

The use of digital compositing has become so commonplace in modern entertainment that it will often go completely under the viewer’s radar. An example of everyday compositing is your TV weatherman. Your weatherman is standing in front of a green screen (or blue screen ), which is removed and replaced with computer-generated maps.

Green screens and blue screens are used in a process called chroma keying or color keying. The use of keying began in the 1930s when a painstaking chemical process, aside from a difficult sync shooting process, was employed at a great cost of time and money. However, with the use of video and digital compositing, the process has become quick and inexpensive.

Essentially, an actor, or subject, is photographed in front of a screen that is either blue or green. The color does not have to be blue or green, but blue and green are used most often because they are in the range of colors most opposite to human skin. Blue, the opposite of yellow, was the traditional choice, which switched over to green when digital compositing became the norm because digital cameras respond better to the higher luminance values of green. When a film or non-digital video camera is in use, blue is often preferred. Green is often used when a shoot takes place outdoors because of the sky.

The color screen background can then be removed. When footage is captured digitally, information is stored in separate color channels. These would be red, green, and blue. In addition, there is a fourth channel, the alpha channel. The alpha channel controls the transparency of the color channels, and in a composite shot the compositor can specify the color range that will receive either a reduced transparency or removal. Then a separate piece of footage can be put behind the color-keyed shot and the combined shot is complete.

Keying is not the only method of employing the use of alpha channels. The use of garbage mattes is often necessary to aid where color keys are too difficult. Garbage mattes usually refer to the process of hand drawing the area that will have a reduced transparency. The adjective “ garbage” refers to the fact that it is usually temporary or used as part of another technique.

When this is not employed as a temporary or supportive measure, the compositor is said to be masking. The reason why this process is not used more often than color keying is due to the fact that it usually requires adjustment frame by frame. Treating footage with a hand-drawn process frame by frame is called r otoscoping.

Rotoscoping is the process of reshaping a matte, but it can also be used to describe a shot that includes a hand-drawn or adjusted technique that requires attention for each individual frame. So, some quick math, a movie has 24 frames per second (fps) whereas a TV show or commercial has approximately 30 fps. Even on a 30-second commercial that would be 900 separate images that a rotoscoper must attend to, which is not always desirable in the quick turn-around entertainment environment we live in.

The digital compositing world comes equipped with little helpers to reduce the need for rotoscoping. One of these is motion tracking. An area of an image can be tracked by the computer so that some other process can be employed to that area. For example, the tutorial called Digital Dismemberment in Chapter 8, we paint out and replace half of an actor’s arm. To avoid rotoscoping, we put a black dot with a marker on our actor’s arm that the computer is able to track and then something could be attached to that point in its place.

Another technique explored in Chapter 7, where we recreate the look from the films Waking Life and A Scanner Darkly. This tutorial discusses batch processing. A batch process is when footage is broken down into its individual still images and then an image editor, Adobe Photoshop, is used to treat each individual image following a user-specified set of commands. However, even with these techniques the process of rotoscoping cannot always be avoided.

Computer-Generated Imagery

Often combined with compositing, the other category of techniques used to solve most visual effects problems is the creation of CGI or CG. What this will entail is either building two- or three-dimensional digital models that, unlike live actors or real world locations can be changed and moved easily around to achieve the desired scene.

While the use of CGI scenes began in the late 1970s, what marked the arrival of what has become very common in today’s visual effects is the 1993 movie Jurassic Park where CGI dinosaurs were convincingly integrated into scenes with live actors. Now, that is not the exception, it’s the norm.

Very often, not just Pixar characters but even sets, helicopters, buildings, and explosions are commonly created through the use of computer-generated graphics that are composited into scenes. This book discusses techniques for creating 2D and 3D graphics in After Effects as well as Apple’s Motion and Autodesk’s Combustion, but these programs can only scratch the surface of the 3D graphics world, as there are quite a few dedicated programs for the purpose of creating and animating 3D characters and worlds.

Three-dimensional character animation has largely r...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Dedication and Acknowledgments
• Chapter 1 How to Use this Book
• Chapter 2 Your Toolboxion
• Chapter 3 Preparing for Your Visual Effects Shot
• Chapter 4 The New Glass Shot
• Chapter 5 Green and Blue Screens
• Chapter 6 Location, Location, Location
• Chapter 7 Digitally Processing Your Footage
• Chapter 8 Horror Effects
• Chapter 9 Action
• Chapter 10 Science Fiction
• Chapter 11 Flashy Techniques
• Chapter 12 Animation
• Chapter 13 Texts Effects
• Chapter 14 Return to Render
• Index