It's All About Workflow

Whether I am visiting a visual effects studio for staff training or talking to students about their previous education I hear the same general comment; the educational institutions teach them how to operate the software, but not much about workflow - how to get things done. They know how to degrain or regrain a shot, but not grain management. They may be able to remove the lens distortion from a shot, but not lens distortion management. I took this as a cue as to what updates to make in the fourth edition of my book, "Digital Compositing for Film and Video". More workflow, please! Let's see an example.

Taking lens distortion management as an example, many beginners try to undistort the original plate, comp the CGI over it, and then re-distort the comp. This workflow is seriously wrong because it softens the original plate twice - once for the undistort and again for the re-distort. So this is the kind of step-by-step workflow information you will find in the 4th edition for lens distortion management:

Learning to composite visual effects is also a process of learning good technique - best practices for common tasks. The idea here is to give the reader the kind of good technique that takes years to learn. Quality and productivity tips are offered for rotoscoping, camera tracking, point tracking and even planar tracking. Best practices are also offered for critical tasks such as keying outside the keyer and color correcting.

Speaking of color correcting, one of the things that artists new to compositing want to know is which knob to adjust for what color correction. Should I use gain or gamma? And what the heck is "lift" anyway? In Chapter 9 Section 9.3 you will find the answers as each color correction operation is explained both mathematically and visually so you will know when to use gamma, for example, and what part of the image it will affect and why. By the way, "lift" scales the RGB values up or down, but the center of scale is code value 1.0, (white) whereas gain scales them with the center of scale at code value 0 (black).

Above is the book's illustration for lift showing the comparable color curve on the left, the affect on the image in the middle, and the affect on the pixel code values on the right. And of course, there is plenty of supportive text to explain everything that is going on. This analysis is repeated for all of the major color correction ops.

For the arduous chore of greenscreen and bluescreen keying there are several advanced techniques offered to make it a bit less infuriating. The Processed Foreground method replicates the fine edge characteristics that the Keylight keyer is famous for. The Screen Correction technique replaces the backing region, regardless of how unevenly lit or patched from disparate cloth panels, with one uniform green or blue color that every keyer will love - without hammering edges. And if you wrestle with spill suppression you might be interested in my Unspill algorithm where you can actually dial in any color you want on despilled edges.

Ever rotoscope a heavily motion-blurred object only to find that when you key it the original background is mixed in with the motion blurred regions? Of course you have. It’s unavoidable. Then you might want to brush up on the Edge Decontamination technique outlined in Chapter 2, Section 2.2.7 that also, by the way, works great for heavily defocused objects because their defocused edges are also unavoidably contaminated by the background. 

Many (perhaps most) visual effects compositors have already purchased earlier editions of this book, so to help them skip to the hot new stuff they will find in Chapter 1, Section 3 "What's New in the 4th Edition" with a long list of new content like this:

Roto Shape Breakdown – strategies for breaking a roto target into multiple shapes for most efficient rotoscoping. Chapter 2 Section 2.7.2

As a further aid to jumping directly to important new content is Chapter 1, Section 4 "Gold Mines" that contain a listing of all the step-by-step workflow examples like this:

Lens Filter Flare - Chapter 11 section 11.1.5.2 – lens filters introduce a type of flaring to the image so learn how to replicate this affect. 

So for the 4th edition it’s all about workflow. More than just understanding the various image processing operations that make up the compositing of a visual effects shot, it's years of production experience compressed into a very readable, dare I say enjoyable, book written by someone that has spent many years in the chair working vfx shots. Do check it out on Amazon.com.

Steve Wright is a 20+ year visual effects compositing veteran who has worked on over 70 feature films and as many broadcast television commercials. A master trainer since 2005, he has taught compositing to over 1000 students and conducted staff training at over two dozen visual effects studios around the world including Pixar, Disney Feature Animation, Reliance MediaWorks, Framestore, and many more. Author of two popular books on compositing (Available on Amazon.com) you can view his training website at www.fxecademy.com.