4th Edition

Digital Compositing for Film and Video Production Workflows and Techniques

By Steve Wright, Steve Wright Copyright 2018
    576 Pages 300 Color Illustrations
    by Routledge

    576 Pages 300 Color Illustrations
    by Routledge

    Written by senior compositor, technical director and master trainer Steve Wright, this book condenses years of production experience into an easy-to-read and highly-informative guide suitable for both working and aspiring visual effects artists.

    This expanded and updated edition of Digital Compositing for Film and Video addresses the problems and difficult choices that professional compositors face on a daily basis with an elegant blend of theory, practical production techniques and workflows. It is written to be software-agnostic, so it is applicable to any brand of software. This edition features many step-by-step workflows, powerful new keying techniques and updates on the latest tech in the visual effects industry.

    Workflow examples for:

    • Grain Management
    • Lens Distortion Management
    • Merging CGI Render Passes
    • Blending Multiple Keys
    • Photorealistic Color Correction
    • Rotoscoping

    Production Techniques for:

    • Keying Difficult Greenscreens
    • Replicating Optical Lens Effects
    • Advanced Spill Suppression
    • Fixing Discoloured Edges
    • Adding Interactive Lighting
    • Managing Motion Blur

    With brand new information on:

    • Working in linear
    • ACES Color Management
    • Light Field Cinematography
    • Planar Tracking
    • Creating Color Difference Keys
    • Premultiply vs. Unpremultiply
    • Deep Compositing
    • VR Stitching
    • 3D Compositing from 2D Images
    • How Color Correction ops Effect Images
    • Color Spaces
    • Retiming Clips
    • Working with Digital Cinema Images
    • OpenColorIO

    A companion website offers images from the examples discussed in the book allowing readers to experiment with the material first-hand.

    About the Author



    Chapter 1 - Getting Started

    1.1 How this Book is Organized

    1.2 Web Content

    1.3 What’s New in the 4th Edition

    1.4 Gold Mines

    1.5 Tool Conventions

    1.5.1 The Slice Tool

    1.5.2 Flowgraphs

    1.5.3 Color Lookup Tables (LUTs)

    1.5.4 Nuke

    1.6 Data Conventions

    1.6.1 Floating Point Data Banding Clipping

    1.6.2 Linear Light Space

    1.6.3 HDR Images

    1.6.4 Stops

    Chapter 2 - Pulling Keys

    2.1 Lumakeys

    2.1.1 How Lumakeys Work

    2.1.2 Making Your Own Luminance Image Variations on the Luminance Equations Non-luminance Monochrome Images

    2.1.3 Making Your Own Lumakeyer

    2.2 Chromakeys

    2.2.1 How Chromakeys Work

    2.2.2 Making Your Own Chromakeyer

    2.2.3 Making a 3D Chromakeyer

    2.3 Difference Mattes

    2.3.1 How Difference Mattes Work

    2.3.2 Making Your Own Difference Matte Making the Difference Image Making the Difference Matte

    2.4 Bump Mattes

    2.5 Color Difference Keys

    2.6 The Blur and Grow Technique

    2.7 Rotoscoping

    2.7.1 Control Point Coherency

    2.7.2 Shape Breakdown Hierarchical Articulation Organization

    2.7.3 Bezier or B-spline?

    2.7.4 Keyframe Strategies On 2’s Binary Multiples Bifurcation Motion Extremes

    2.7.5 Motion Blur Spline Placement Edge Decontamination

    2.7.6 Inspection

    Chapter 3 - Working with Keyers

    3.1 Keyers

    3.2 How Keyers Work

    3.2.1 Calculating the Color Difference Matte The Theory Pulling the Raw Matte A Simplified Example A Slightly More Realistic Case And Now, The Real World Matte Edge Penetration

    3.2.2 Scaling the Raw Matte

    3.3 The After Effects Keyer

    3.3.1 Step-by-Step Procedure

    3.3.2 Flowgraph of the After Effects Keyer

    3.4 Typical Greenscreen Problems

    3.4.1 Over Exposed

    3.4.2 Under Exposed

    3.4.3 Impure Greenscreens

    3.4.4 Uneven Lighting

    3.5 Preprocessing the Greenscreen

    3.5.1 Denoise and Degrain

    3.5.2 Screen Leveling

    3.5.3 Local Suppression

    3.5.4 Channel Clamping

    3.5.5 Channel Shifting

    3.5.6 Screen Correction Step-by-Step Procedure Pictographic Flow Chart Flowgraph of the Screen Correction Procedure How to Create a Clean Greenscreen

    Chapter 4 - Refining Mattes

    4.1 Gamma Slamming

    4.2 Garbage Mattes

    4.2.1 Pre-matting

    4.2.2 Post-matting

    4.3 Filtering the Matte

    4.3.1 Noise Suppression with a Median Filter

    4.3.2 Softer Edges

    4.3.3 Controlling the Blur Operation The Blur Radius The Blur Percentage Masking the Blur

    4.4 Adjusting the Matte Size

    4.4.1 Eroding a Matte with Blur and Scale

    4.4.2 Dilating a Matte with Blur and Scale

    4.4.3 Blurring Out

    4.4.4 Sculpting Edges

    4.5 Edge Masks

    Chapter 5 - Spill Suppression

    5.1 Sources of Spill

    5.2 The Despill Operation

    5.3 Despill Algorithms

    5.3.1 Green Limited by Red Implementing the Algorithm The Spillmap

    5.3.2 Green Limited by the Average of Red and Blue

    5.3.3 An Adjustable Despill

    5.3.4 What About Blue Spill?

    5.3.5 Refining the Despill Channel shifting Spillmap Scaling Mixing Despills Matting Despills Together

    5.4 The Unspill Operation

    5.4.1 How to Set It Up

    5.4.2 Grading to the Backing Color

    5.5 Despill Artifacts

    5.5.1 Finding the Artifacts

    5.5.2 Hue Shifts

    5.5.3 Dark Edges

    5.5.4 Fixing Despill Artifacts

    5.6 Edge Grading

    5.7 Edge Extension

    Chapter 6 - the Composite

    6.1 Premultiply vs. Unpremultiply

    6.1.1 Premultiply

    6.1.2 Unpremultiply

    6.1.3 The Double Premultiply

    6.2 The Composite

    6.2.1 The Over Composite

    6.2.2 The KeyMix Composite

    6.2.3 The AddMix Composite How it Works How to Build It How to Use It

    6.2.4 The Processed Foreground Method The Workflow What to Watch Out For

    6.3 Compositing With a Keyer

    6.3.1 Soft Comp/Hard Comp

    6.3.2 "Cut and Paste" Keyer Compositing

    6.4 Compositing Outside the Keyer

    6.4.1 The Single Key

    6.4.2 The Uberkey

    6.4.3 Soft Key/Hard Key

    6.4.4 The Additive Keyer

    6.5 Stereo Compositing

    6.5.1 Anaglyph

    6.5.2 Stereopsis

    6.5.3 Stereoscopy

    6.5.4 The Stereo Conversion Process

    6.5.5 Depth Grading Scene Transition The Dashboard Effect Window Violation Miniaturization Divergence

    6.5.6 Stereo Compositing Dual View Display Split and Join Views Disparity Maps

    Chapter 7 - Compositing CGI

    7.1 Multi-Pass CGI Compositing

    7.1.1 Process Verification for Your Renderer

    7.1.2 Render Passes

    7.1.3 Lighting Passes Render Passes Workflow Beauty Pass Workflow

    7.1.4 AOVs

    7.1.5 ID Passes

    7.1.6 Normals Relighting

    7.2 EXR File Format

    7.2.1 Film Scans

    7.2.2 Linear Lightspace

    7.2.3 Arbitrary Image Channels

    7.3 HDR Images

    7.4 Deep Compositing

    7.4.1 Deep Images

    7.4.2 The Layering Complexity Problem

    7.4.3 The Depth Compositing Edge Problem

    7.4.4 The Re-rendering Problem

    7.4.5 Deep Compositing with Live Action

    Chapter 8 - 3D Compositing

    8.1 A Short Course in 3D

    8.1.1 the 3D Coordinate System

    8.1.2 Vertices

    8.1.3 Meshes

    8.1.4 Surface Normals

    8.1.5 UV Coordinates

    8.1.6 Map Projection

    8.1.7 UV Projection

    8.1.8 3D Geometry

    8.1.9 Geometric Transformations

    8.1.10 Geometric Deformations Image Displacement Noise Displacement Deformation Lattice

    8.1.11 Point Clouds

    8.1.12 Lights

    8.1.13 Shaders

    8.1.14 Reflection Mapping

    8.1.15 Ray Tracing

    8.1.16 Image Based Lighting

    8.1.17 Cameras

    8.2 3D Compositing

    8.2.1 3D compositing from 2D images

    8.2.2 Pan and Tile

    8.2.3 Camera Projection

    8.2.4 Multiplane Shots

    8.2.5 Set Extension

    8.2.6 3D Backgrounds

    8.3 Alembic Geometry

    8.3.1 The Simple Case

    8.3.2 Scenegraphs

    8.3.3 Advantages Over FBX

    8.4 Camera Tracking

    8.4.1 Step 1 - Feature Tracking

    8.4.2 Step 2 - The Solve

    8.4.3 Step 3 – Build the Scene

    8.4.4 Placing the Geometry

    8.4.5 A Large Outdoor Scene

    Chapter 9 - Color Correction

    9.1 The Behavior of Light

    9.1.1 The Inverse Square Law

    9.1.2 Diffuse Reflections

    9.1.3 Specular Reflections

    9.1.4 Bounce Light

    9.1.5 Scattering

    9.2 Gamma

    9.2.1 The Math

    9.2.2 Why Do We Need Gamma?

    9.3 The Affect of Color Operations

    9.3.1 Lift

    9.3.2 Gamma

    9.3.3 Gain

    9.3.4 Offset

    9.3.5 Saturation

    9.3.6 Color Grading vs. Color Correcting

    9.3.7 Increasing Contrast with the "S" Curve

    9.3.8 Histograms

    9.3.9 Channel Swapping

    9.3.10 Premultiply vs. Unpremultiply - again

    9.4 Matching the Light Space

    9.4.1 Brightness and Contrast Matching the Black and White Points Matching the Midtones Gamma Slamming

    9.4.2 Matching Color Grayscale Balancing Flesh Tones The "Constant Green" Method of Color Correction Daylight Specular Highlights

    9.4.3 Lighting Direction

    9.4.4 Quality of Light Sources Creating Softer Lighting Creating Harsher Lighting

    9.4.5 Non-linear Gradients for Color Correction

    9.4.6 The DI Process

    9.4.7 A Checklist

    Chapter 10 - Sweetening the Comp

    10.1 Layer Integration

    10.2 Interactive Lighting

    10.3 Edge Blending

    10.4 Light Wrap

    10.5 Creating Shadows

    10.5.1 Edge Characteristics

    10.5.2 Density

    10.5.3 Color

    10.5.4 Faux Shadows

    10.5.5 Shadow Warping

    10.5.6 Contact Shadows

    10.6 Atmospheric Haze

    10.7 Adding a Glow

    10.8 Grain Management

    10.8.1 Grain Characteristics

    10.8.2 Regraining Techniques Regrain Tool Lifted Grain Grain Rescue

    10.8.3 Grain Management Workflows Live Over Live Live Over CGI CGI Over Live CGI Over CGI Still Photos

    10.9 Managing Clipping

    Chapter 11 - Camera Effects

    11.1 Lens Effects

    11.1.1 Lens Distortion

    11.1.2 Depth of Field

    11.1.3 Vignetting

    11.1.4 Lens Defects Spherical Aberration Astigmatism Chromatic Aberration

    11.1.5 Glows and Flares Lens Flare Lens Filter Flare Diffraction Glows Veiling Glare

    11.1.6 Grain

    11.2 Lens Distortion Workflows

    11.2.1 CGI Over Live Action

    11.2.2 Live Action Over CGI

    11.2.3 CGI Over CGI

    11.2.4 Live Action Over Live Action

    11.3 Matching the Focus

    11.3.1 Using a Blur for Defocus

    11.3.2 How to Simulate a Defocus

    11.3.3 Sharpening Sharpening Operations Unsharp Masks Making Your Own Unsharp Mask

    11.4 Rolling shutter

    Chapter 12 - Digital Color

    12.1 Color Spaces

    12.1.1 Primary Chromaticities

    12.1.2 Units of Measure

    12.1.3 Transfer Function

    12.1.4 Gamut

    12.1.5 HSV and HSL

    12.1.6 Log and Linear

    12.2 Working in Linear

    12.2.1 What Exactly is Linear?

    12.2.2 Color Operations

    12.2.3 Transformations and Filtering

    12.2.4 CGI

    12.3 Metadata

    12.4 OpenColorIO

    12.5 ACES Color Management

    12.5.1 The ACES Workflow

    12.5.2 The ACES Gamut

    12.5.3 What About Video Productions?

    Chapter 13 - Image Blending

    13.1 Image Blending in Linear Light Space

    13.1.1 Image Blending Operations

    13.1.2 Compositing Operations

    13.1.3 Matching the sRGB Look in Linear All sRGB Color Space sRGB Within Linear

    13.2 Alpha Compositing Operations

    13.3 Image Blending Operations

    13.3.1 The Screen Operation Adjusting the Appearance

    13.3.2 The Weighted Screen Operation

    13.3.3 Multiply Adjusting the Appearance

    13.3.4 Maximum

    13.3.5 Minimum

    13.3.6 Absolute Difference

    13.4 Adobe Photoshop Blending Modes

    13.4.1 Simple Blending Modes

    13.4.2 Complex Blending Modes

    13.5 Slot Gags

    13.6 Retiming Clips

    13.6.1 Constant Speed Changes

    13.6.2 Variable Speed Changes

    13.6.3 Interpolation Methods Nearest Neighbor Frame Average Motion Estimation

    13.7 VR Stitching

    13.7.1 Workflow Overview

    13.7.2 Removing Lens Distortion

    13.7.3 Building a Matching Computer Rig

    13.7.4 Projecting Onto the Panosphere

    13.7.5 The Stitching Process

    13.7.6 Coping with Parallax

    13.7.7 Exposure Correction

    13.7.8 Visual Effects

    Chapter 14 - Transforms and Tracking

    14.1 Geometric transforms

    14.1.1 2D Transforms Translation Float vs. Integer Translation Source and Destination Movement Rotation Pivot Points Resize vs. Scale Pivot Points Skew Corner Pinning

    14.1.2 Managing Motion blur Transform Motion Blur Motion UV Motion Blur Speed Changes

    14.1.3 3D Transforms

    14.1.4 Filtering The Effects of Filtering Twinkling Starfields Choosing a Filter

    14.1.5 Lining Up Images Offset Mask Lineup Display Edge Detection Lineup Display The Pivot Point Lineup Procedure

    14.2 Image Displacement

    14.3 Warps and Morphs

    14.3.1 Mesh Warps

    14.3.2 Spline Warps

    14.3.3 Morphs

    14.3.4 Tips, Tricks and Techniques

    14.4 Point Tracking

    14.4.1 The Tracking Operation Selecting Good Tracking Targets Bad Tracking Targets Tracker Enable/Disable Offset Tracking Keep Shape and Follow Shape Pre-processing the Clip Coping with Grain Tracking Workflow Cleaning up Tracking Data The Stability Test Reasons for Failure

    14.4.2 Match-Move 2D Transforms Corner Pinning

    14.4.3 Stabilizing The Repo Problem Motion Smoothing For Rotoscoping

    14.5 Planar Tracking

    14.5.1 The Planar Grid

    14.5.2 Drift Correction

    14.5.3 Exporting Data

    14.5.4 Roto Assist

    Chapter 15 - Digital Images

    15.1 HD Video

    15.1.1 Frame Formats

    15.1.2 Anamorphic video

    15.1.3 Scan Modes

    15.1.4 Working with Interlaced Video Deinterlacing Scan Line Interpolation Field Averaging

    15.1.5 Color Subsampling

    15.1.6 Keying with 4:2:2 Video

    15.1.7 Frame Rates 24, 25, 30, 60 fps 23.98, 29.97, 59.94 fps

    15.1.8 Timecodes

    15.1.9 Video File Formats

    15.1.10 Telecine The 3:2 Pull-down The 3:2 Pull-up

    15.2 Digital Cinema Images

    15.2.1 Digital Camera Advantages

    15.2.2 The Bayer Array

    15.2.3 Sensor Crop

    15.2.4 HFR – High Frame Rate

    15.2.5 The DCI

    15.3 Film Scans

    15.3.1 Grain

    15.3.2 the "Safe-to" Window

    15.3.3 Apertures

    15.3.4 Aspect Ratios

    15.3.5 Film formats Full Aperture Academy Aperture Super 35 Formats Cinemascope Working with Cscope 3 Perf Film VistaVision 65mm/70mm IMAX

    15.4 Log Images

    15.4.1 What Are Log Images?

    15.4.2 Why We Need Log Images Human Vision Data Compression Working with Log Images

    15.5 Light Field Cinematography

    15.5.1 How it Works

    15.5.2 The Impact on Visual Effects Deep Images Arbitrary Depth of Field Depth Maps Stereo Through a Single Lens Volumetric Optical Flow Position Pass Point Clouds Mattes Normals and Normal Relighting Camera Tracking

    15.5.3 When, and How Much?




    Steve Wright is a visual effects pioneer and a 20-year veteran of visual effects compositing on over 70 feature films and many broadcast television commercials. With extensive production experience and a knack for the math and science of visual effects he is a world-recognized expert on visual effects compositing. Since 2005 he has been a master trainer in compositing visual effects, providing staff training to over 25 visual effects studios around the world including Pixar Animation Studios, Disney Feature Animation, Troublemaker Studios, New Deal Studios, and Reliance MediaWorks, along with many others. He has also trained over 1,000 artists in compositing.

    Visit Steve’s training website at www.fxecademy.com

    "This book covers both the basic fundamentals and the advanced techniques of compositing, but Steve also presents the reader with a deeper background on the task at hand. You're not just getting a how-to manual, but an understanding of why you do it."

    —Patrick Tubach, VFX Supervisor, Industrial Light & Magic

    "Digital Compositing for Film and Video is the must have book for all compositors at all levels. I always keep copies close on hand for my artists to use and still refer to it often myself. The book covers the skills all compositors must know and the techniques needed when you are fighting tricky shots."

    —Jeffrey Jasper, CTO, JTS Productions, LLC

    "What’s astounding about this book is that, for the last 16 years, every edition has been ahead of its time in terms of teaching and explaining the different techniques, technologies, and tools used on a daily basis by compositors around the world. Steve Wright has managed, once again, to stay ahead of the game and spearhead the education of current and future compositors."

    —Ara Khanikian, VFX Supervisor, Rodeo FX