Get your foot in the studio door by learning the art of matchmoving
Matchmoving is a technique that allows computer graphics to be inserted into live-action footage with correct position, scale, orientation, and motion. Also known as motion tracking, it's what allows movie monsters to run down Main Street and robots to run through crowds--and look real. Now this unique book from a top expert from Industrial Light and Magic teaches you the art of matchmoving.
With step-by-step tutorials and pages of examples, this book first explains the basics and then shows you professional techniques, from 3D calibration and tracking, to stereoscopy, and more.
- Explains concepts and teaches professional techniques for successful matchmoving
- Authored by a top matchmove specialist from Industrial Light and Magic, who walks you through step-by-step tutorials and impressive examples
- Covers matchmoving basics, 2D tracking, 3D calibration and tracking, automatic tracking, cameras, integrating matchmoves, and stereoscopy
Learn how studio visual effects professionals make all the right matchmoves with Matchmoving: The Invisible Art of Camera Tracking 2nd Edition.
Table of Contents:
Introduction xxi Chapter 1 The Basics of Matchmoving 1
Exploring a Typical Matchmove 2
Moving from 3D to 2D and Back Again 4
Understanding the Matchmoving Process 5
Evaluating the Footage 5
Applying Information 6
Defining the Camera 6
Fitting the Set 7
Testing the Matchmove 9
Delivering the Scene 9
Matchmoving in the Production Pipeline 9
Perspective Matching Tutorial 10
Gathering the Data 11
Setting Up the Camera 13
Adding Rough Geometry and Refining the Camera 15
Creating a Camera Rig 16
Evaluating and Adjusting the Camera 18
Chapter 2 Matchmoving Software 23
Using Matchmoving Programs 24
Introducing Photogrammetry 24
Calibration 25
The Optics of Photography 26
Projection 28
Building a Better Camera 31
Parallax: A Matchmover’s Best Friend 38
Understanding How Matchmoving Programs Work 40
Requirements for Matchmoving Programs 41
Chapter 3 2D Tracking 43
Understanding the 2D Tracking Process 44
Exploring the Anatomy of a 2D Track 45
Track Placement: Making Every Track Count 47
Sample the 3D Space 47
Maintain the Minimum Number of Tracks 48
Track Stationary Objects 49
Track “True” 3D Positions 50
Getting Tracks to Stick 51
Following Hints for Effective 2D Tracking 52
Handling Plate Issues 54
Motion Blur 55
Soft Focus or Rack Focus 56
Occlusion 56
Noise 58
Low-Contrast Features 58
Lack of Trackable Features 59
Optimizing the Plate for 2D Tracking 61
2D Tracking Tutorial 62
Evaluating the Shot 63
Placing the First Tracks in SynthEyes 63
Choosing Your Tracks 66
Adding the Remaining Tracks 66
Chapter 4 3D Calibration 69
Understanding “Good” Calibration 70
Evaluating Error 70
Calibrating Your Cameras 72
Finding the Right Fit 72
Calibration Tutorial 73
Evaluating the Solution 77
Evaluating the 3D Nulls 77
Evaluating the 3D Space 78
Rendering the Matchmove 79
When Good Solutions Go Bad 80
Determining Camera Moves 81
Dolly/Crane/Moving Camera 81
Pan/Tilt Shots 82
Slight Dollies/Translation 82
Lock-offs 83
Zoom Shots 83
Shaky Footage/Handheld Footage 84
Setting Up a Coordinate System 84
Coordinate System Tutorial 85
Exporting the Scene 88
Chapter 5 Automatic Tracking 91
Tracking on Autopilot 92
Editing Automatic Tracks 93
Using Masks 96
Reaping the Benefits of Automatic Tracking 97
Noise Reduction 97
Environment Definition 98
Implementing the Automatic Tracking Process 99
Automatic Tracking Tutorial 99
Chapter 6 Cameras 107
How Film Cameras Work 108
Lenses 110
Focal Length 111
Focus 113
Nodality 113
Film Backs 115
Film Back and Focal Length 115
Digital Cameras 117
CMOS, CCD, and Rolling Shutter 119
Camera Information 121
Format 122
Lens Distortion 123
Anamorphic Distortion 127
Capture and Digitization 128
Video 128
Film 129
HD 130
Keeping It All Straight 130
Chapter 7 Set Fitting 133
Fitting the Camera 134
Checking the Matchmove 135
Proxy Geometry 135
Checkerboards 137
Fitting the Set 138
Moving the Camera 138
Scaling the Camera 139
Creating Camera Rigs 141
Set-Fitting Tutorial 141
Examining the Exported Scene 142
Adding Test Geometry 143
Moving the Camera 144
Texturing the Objects 149
Performing the First Tests 150
Placing the Matchmove in the Set 152
Altering the Coordinate System 156
Delivering the Scene 156
Tutorial Continued 157
Chapter 8 Being on Set 159
Getting the Right Information 160
Getting Camera Information 162
Before the Shoot 162
During the Shoot 162
After the Shoot 165
Marking Up the Set 165
Tracking Markers for a Green Screen or Blue Screen 166
Tracking Markers for Set Pieces 167
Tracking Markers for Exterior Scenes 168
Working with Others on Set 168
Building a Matchmoving Kit 172
Shooting Distortion Grids 173
Chapter 9 Matchamation 175
Understanding the Basic Technique 176
Establishing the Distance to the Camera 176
Setting the Initial Pose 177
Using Nonlinear Animation Techniques 178
Analyzing the Movement 178
Making the First Pass 179
Making Additional Passes/Tweaks 180
Making Model Changes 181
Working with Imperfect Data 181
Matchamation Tutorial 182
Setting Up the Camera 182
Creating the Proxy Object 184
Creating a Matchamation Rig 185
Analyzing the Motion 186
Making the First Pass 188
Making the Second Pass 191
Making Additional Passes 194
Chapter 10 Troubleshooting and Advanced Techniques 197
Performing Effective Troubleshooting 198
Following a Troubleshooting Checklist 199
Check the Camera’s Motion 199
Check Set Placement and Fitting 201
Scrutinize 2D Tracking Closely 202
Check for Plate Issues 202
Diagnosing the Problem 203
No nulls are visible after calibration 204
Nulls are all in a line or a single point 204
The camera path jumps suddenly to another position or is extremely jagged and chaotic 204
Everything lines up on the fi rst frame but quickly slips off 205
Noise or jitter appears in the camera’s motion path 205
Objects appear to tear away from the plate feature during areas of heavy motion blur 206
Using Advanced Tools and Tricks 206
Using Advanced 2D Tracking Tools 206
Using Constraints 207
Working with Reference Photos 209
Forcing a Calibration 210
Faking the Focal Length 210
Using Survey Data 211
Chapter 11 Object Tracking 215
The Object-Tracking Process 216
Understanding Object Tracking vs Matchamation 216
Following the Object-Tracking Workfl ow 216
Converting a Camera Track to an Object Track 217
Object-Tracking Tutorial 219
Common Problems with Object Tracking 229
2D Tracking Problems 229
Difficult Object Motion 230
Object Not Truly Rigid 231
Tracking Human Faces 232
Geometry Tracking 233
Geometry-Tracking Tutorial 234
Common Problems with Geometry Tracking 237
Advanced Object Tracking 237
Moving Camera/Moving Object 238
Tracking Deforming Objects 239
Chapter 12 Multipurposing Matchmoving Data 241
Creating Special Cameras 242
Extending or Enhancing Matchmoves 242
Blending Matchmoves 243
Blending Cameras in Maya 245
Object Track as a Camera Track 251
Matchmoves for Paint Work: “Patchmoves” 252
Matchmoves for Compositors 253
Matchmoves for TD Work 254
Not the End of the Road 256
Chapter 13 Stereo 257
Understanding Stereoscopy 258
Interocular Distance 259
Convergence 261
How IO and Convergence Affect Stereo Depth 264
Adjusting Stereo Parameters in Postproduction 265
Stereo Postconversion 266
Filming Stereo Footage 266
Side-By-Side Rigs 266
Beam-Splitter Rigs 267
Dual-Lens Cameras 269
Viewing Stereo Footage 269
Anaglyphs 270
Polarized Lens Systems 271
Modern Stereo Projection 271
Active Shutter Systems 272
Matchmoving Stereo Footage 272
2D Tracking 273
Solving 273
Set Fitting 275
Evaluating the Matchmove 275
Overcoming Common Problems 276
Problems with 2D Tracking 276
Problems with 3D Tracking 277
Focal-Length Issues 277
Appendix A Resources 279
Appendix B Matchmoving Software and Useful Links 281
Matchmoving Software 282
Other Useful Programs 283
Books 283
Websites 284
Appendix C Film Formats 285
16 mm Formats 286
35 mm Formats 286
Large Formats 287
Digital Formats 287
Calculating the Film Back for Cropped Images 288
Glossary 289
Index 299
About the Author :
Tim Dobbert is a layout lead at Industrial Light & Magic in San Francisco and has been in the visual effects industry for over ten years. He has worked as a matchmover and digital artist on over 25 feature films, including Avatar, Pirates of the Caribbean: On Stranger Tides, and Harry Potter and the Goblet of Fire. In addition to teaching university classes in matchmoving and image-based content creation, he has lectured all over the world on the subject.
