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Setting Up a Composite “ Education is important—I think people need to make sure that they’re learning to be artists and not just learning tools.” — Gianni Aliotti, lead lighter, DreamWorks Animation Before beginning a composite, it’s important to understand the fundamental differences between layer- and node-based compositing systems. A strong knowledge of common image resolutions and frame rates will allow you to make correct decisions.
2 chapter 1 ■ Setting Up a Composite Compositing Challenge Digital compositing is the process of digitally assembling multiple images or image sequences into a single piece of motion picture or digital video footage. The goal of a successful digital composite is to make the source material appear as if it has always existed in the same location or scene. Digital compositing is closely related to photomontage and compositing (without the word digital).
■ Compositing Examples 3 5. The ground plane layer is color graded to make it lighter. In addition, a CG female warrior is brought in as a layer. At this point, it’s difficult to see the warrior over the background. 6. The warrior layer is color graded. A smoke render is sandwiched between the foreground and the robot. A glow render is added to the end of the warrior’s weapon. 7. A smoke render is added to the foreground as a top layer. CG lasers and starbursts are imported. 8.
4 chapter 1 ■ Setting Up a Composite Click 3X for Sharp Figure 1.2 shows five steps of a Flame composite created by Aaron Vasquez at Click 3X, a motion graphics and visual effects studio in New York City. (To read an interview with Aaron Vasquez, see Chapter 11, "Working with 2.5D and 3D.") The composite is one shot of a commercial for Sharp featuring the Aquos television. The breakdown is as follows: 1. A peacock is filmed against greenscreen. The bird slowly rotates on a turntable. 2.
■ Compositing Examples 5 AILV for Spec Commercial Figure 1.3 shows six steps of an After Effects composite created by the author and students at the Art Institute of Las Vegas (AILV). The composite is one shot of a spec commercial advertising a futuristic copier. (A spec is a demo used to show filmmaking or animation skills.) The breakdown is as follows: 1. An actress is shot against bluescreen. 2. Stock footage of a city is defocused (that is, blurred in an optically accurate way). 3.
6 chapter 1 ■ Setting Up a Composite issues, RGB ID render passes of the model are imported and are converted to holdout mattes. ID passes offer a means to separate 3D objects. In this case, foreground, midground, and background objects are separated. The final composite is color graded. Depth of field is applied to the composite to soften the immediate foreground and background. Artificial glare is also added to make the daylight lighting appear more intense. 3.
■ Layers vs. Nodes 7 Layers vs. Nodes After Effects and Nuke exemplify the two major approaches to compositing: layer based and node based. Layer-based programs represent each imported and utilized digital still or image sequence as a layer along a timeline. Each layer possesses its own set of transformations and special-effect filters. The layers are stacked and processed in order from bottom to top (see Figure 1.5).
8 chapter 1 ■ Setting Up a Composite Industry Perspective: Compositing Software Overview In preparation for this book, 19 expert compositors from feature animation studios, visual effects houses, and commercial production facilities in Los Angeles, New York, and San Francisco (as well as New Zealand and the United Kingdom) were interviewed. As such, a survey of popular compositing software was taken. The two most consistently named programs were Flame (or its sister, Inferno) and After Effects.
■ Resolutions and Frame Rates 9 Common Resolutions and Aspect Ratios You can break image resolutions into three categories: SDTV, HDTV, and motion picture film. SDTV (Standard-Definition Television) includes broadcast television and video that possesses fewer than 720 lines of vertical resolution. SDTV may be analog or digital. HDTV (High-Definition Television) includes broadcast television and video that possesses 720 or more lines of vertical resolution. HDTV, as a newer format, is digital.
10 chapter 1 ■ Setting Up a Composite of 1.07. In contrast, D-3, D-5, and D-5 HD are newer digital formats developed by Panasonic. D-5 HD supports common HDTV resolutions and frame rates. NTSC and PAL DV DV has been the standard for SDTV consumer digital video capture since the mid-1990s. The NSTC version is 720×480 with a PAR of 0.9. PAL DV is identical to PAL D1. NTSC and PAL 16:9 Widescreen variations of D1 and DV are commonly called 16:9.
■ Resolutions and Frame Rates 11 support 24p, which records progressive frames at 24 fps. Other cameras offer 24p Advanced, which records 24 fps by repeating frames with a 30 fps format. The frame rate of PAL, SECAM, and DVB video and broadcast television is 25. The ATSC HDTV formats 1080p, 1080i, and 720p, as well as 480p EDTV, support a frame rate of 30. If the video is interlaced, 30 fps is sometimes expressed as 60, or 60 fields-persecond.
12 chapter 1 ■ Setting Up a Composite Tips & Tricks: Progressive-Frame Tutorials 21 out of 22 tutorials included in this book use progressive-frame footage. Any footage that was shot interlaced has been converted to progressive frames. This was done to keep the tutorials relatively compact and to place the emphasis on various techniques, tools, effects, and nodes. In addition, this allows footage to be shared between After Effects and Nuke.
■ Setting Up a Composite 13 Figure 1.9 The Composition Settings dialog box Figure 1.10 The expanded Project panel with 3 compositions and 12 pieces of footage Importing Footage To import an image, image sequence, QuickTime movie, or AVI movie into After Effects, choose File → Import → File. If you are importing an image sequence, select the first image of the sequence. By default, the program imports consecutively numbered frames 52615c01.
14 chapter 1 ■ Setting Up a Composite as a single unit. This assumes that the files follow the following naming convention: name.#.extension. Extension is the three-letter file format code, such as tga. The program also requires a consistent number of numeric placeholders within the sequence. For example, if a sequence has 200 frames, there must be three placeholders, as with name.###.ext. When footage is imported, it’s placed in the Project panel.
15 ■ Setting Up a Composite A I J K L B M N O P Q R C D E F G H S T Figure 1.12 Layer outline of Timeline panel. The composition switches include (A) Open Parent, (B) Live Update, (C) Draft 3D, (D) Hide Shy Layers, (E) Frame Blending, (F) Motion Blur, (G) Brainstorm, and (H) Graph Editor.
16 chapter 1 ■ Setting Up a Composite Lock, when toggle on, prevents alteration of the layer’s properties or transformations. Shy hides the layer if the Hide Shy Layers composition switch is toggled on. If a layer is hidden, it is no longer visible in the layer outline, but it continues to influence the composite. Collapse Transformations, if toggled on, preserves image integrity for nested compositions. For example, the following may occur: 1. 2. 3. 4.
■ Setting Up a Composite 17 Figure 1.13 The Precompose dialog box 2. If a single layer is selected and Leave All Attributes In Comp is chosen, the selected layer is left at its original location. However, a duplicate of the layer is placed in a new composition with a name determined by the New Composition Name cell. If Move All Attributes Into The New Composition is selected, the selected layer or layers are moved to the new composition. The new composition is placed at the layers’ original location.
18 chapter 1 ■ Setting Up a Composite While the switches and menus will be described throughout the remaining chapters, a few are worth noting here: Magnification Ratio Popup menu zooms in or out of the view. To scroll left/right or up/ down in a viewer, LMB+drag with the Hand tool (to the right of the Selection tool). Choose Grid And Guide Options menu allows you to apply Title/Action Safe, Grid, and Ruler overlays to the view.
■ Setting Up a Composite 19 The AE Flowchart After Effects can display compositions and their relationships as a flowchart (node network). To display the flowchart, toggle on the Comp Flowchart View switch in the Composition panel or choose Composition → Comp Flowchart View. The flowFootage node chart is opened in a new Flowchart panel. You can display footage, solids, layers, and Layer node with effects list effects nodes by toggling on the display buttons at the bottom left of the Flowchart panel.
20 chapter 1 ■ Setting Up a Composite Figure 1.16 The Render Queue tab with Comp 1 queued Figure 1.17 The Render Settings dialog box The Output Module section sets the render format. To choose a different format, click the word Lossless. In the Output Module Settings dialog box, the Format menu lists all the formats supported by After Effects that are detected on the local machine (see Figure 1.18).
■ Setting Up a Composite 21 alpha channel, change the menu to RGB+Alpha. You can also choose to render straight or premultiplied alpha through the Color menu. (For information on alpha and premultiplication, see Chapter 3). Finally, the Output Module Settings dialog box offers a means to rescale or crop an output through the Stretch and Crop check boxes. Note that the dialog box carries a Color Management tab, which allows you to render a composite to a specific color space.
22 chapter 1 ■ Setting Up a Composite box to Upper Field First or Lower Field First (the field dominance should match the intended output format). During the render, the program creates the appropriate interlacing. Note that the interlacing will be successful only if QuickTime Movie, AVI (Video For Windows), or Windows Media is selected as the output format; if you choose to render an image sequence, the fields are combined without averaging or interpolation.
■ Setting Up a Composite 23 and that interlaced video is imported into After Effects, you can remove the 3:2 pulldown and thus return the motion picture footage to 23.976 fps, which is close to its original 24 fps. This process is commonly referred to as inverse telecine. To apply inverse telecine, open the Interpret Footage dialog box, set the Separate Fields menu to the appropriate field dominance, and click the Guess 3:2 Pulldown button (see Figure 1.21).
24 chapter 1 ■ Setting Up a Composite Figure 1.22 A Read node’s properties panel Within the Read node’s properties panel, you can set the color space and alpha premultiplication of the imported files. These parameters are discussed in Chapter 2 and Chapter 3. If the resolution of imported footage does not match the Full Size Format setting in the Project Settings properties panel, the footage will not “fit” the project resolution frame. Thus it may be necessary to connect a Reformat node.
■ Setting Up a Composite 25 • To duplicate a node with its current setting, select the node and choose Edit → Duplicate from the menu bar. • You can clone a node by selecting the node and choosing Edit → Clone from the menu bar. Cloning differs from duplication in that the cloned node maintains an active link to the original node (see Figure 1.24). Thus, if the properties of the original node are updated, the updated information is passed to the cloned node.
26 chapter 1 ■ Setting Up a Composite Figure 1.26 One viewer connected to three nodes Aside from displaying the outputs of various viewers, the Viewer pane carries a number of menus and controls (see Figure 1.27). These include the ability to control the timeline; display different channels; adjust the viewer f-stop, gain, and gamma; pick a particular display LUT; and switch between 2D and 3D camera views. A B I J C D K L E M N O F G H P Q R S T Figure 1.
■ Setting Up a Composite 27 averaged to speed up the viewer update. For example, if the Downrez menu is set to 16, the project’s horizontal and vertical resolution is reduced to 1/16th. Toggle Proxy allows you to switch to a low-resolution version of the composite. For this to work, the Proxy check box in the Project Settings properties panel must be selected. The degree to which the image is reduced is based upon the Proxy Mode menu, which can be set to Format or Scale.
28 chapter 1 ■ Setting Up a Composite Region-Of-Interest, when toggled on, creates a region box in the viewer. Updates occur only within the region box. You can alter the size of the box by LMB+dragging the box edges. To reposition the box, LMB+drag the center crosshair. Pause, when toggled on, prevents the viewer from updating, even when the node network is updated or parameter values are changed. Update, when clicked, forces an update, even if the Pause button is toggled on.
■ Setting Up a Composite 29 To center the rendered movie in the FrameCycler viewer, press Ctrl+Home. To scroll within the viewer, Ctrl+MMB+drag. To zoom in or out, set the Zoom menu (directly above the time controls). To see the render at full size, set the Zoom menu to Resample Off. You can interactively scrub the timeline by RMB+dragging left or right in the viewer or LMB+dragging the playhead bar on the timeline. The time controls function as they do in any standard player.
30 chapter 1 ■ Setting Up a Composite Interlacing and 3:2 Pulldown in Nuke Figure 1.31 A DeInterlace node removes interlacing with the help of a Transform and Reformat node. A sample Nuke script is included as deinterlace.nk in the Tutorials folder on the DVD. Nuke 5.1 carries a hidden DeInterlace node. To access the node, press the X key to bring up the Command Line window. With the Script radio buttons set to TCL, enter DeInterlace in the cell and click OK (note the capitalization).
■ Setting Up a Composite 2. 3. 4. 5. 6. 7. 52615c01.indd 31 31 space) menus. It’s important to set these menus at the start of each project. Chapter 2 discusses bit depths and color space in great detail. For this tutorial, Depth may be left at 8 Bits Per Channel and Working Space may be left set to None. Click the OK button. Choose Composition → New Composition. In the Composition Settings dialog box, change the Preset menu to HDV/HDTV 720 29.97.
32 chapter 1 ■ Setting Up a Composite Nuke Tutorial 1: Working with the Reformat Node Working with source footage that possesses different resolutions can lead to formatting and composition problems unless special steps are taken. 1. Open Nuke. Choose Edit → Project Settings from the menu bar. In the Project Settings property panel, set the Full Size Format menu to 1K_Super_35(full-ap). This creates a project with a resolution of 1024×778. Note that the resolution bears no indication of a PAR.
■ Setting Up a Composite 33 frame. The Reformat node forces the Read2 output to conform to the output format established by the project settings. For additional information on the Reformat node, see Chapter 5. The tutorial is complete (see Figure 1.34). A sample Nuke script is included as nuke1.nk in the Tutorials folder on the DVD. Figure 1.33 The initial composite. The ouput size is forced to 2048 × 1556. Figure 1.
34 chapter 1 ■ Setting Up a Composite Interview: Dorne Huebler, Industrial Light & Magic, San Francisco Dorne Huebler graduated from the California Institute of the Arts in 1980. By the time he graduated, he was already creating graphics and visual effects for commercials. In 1995, he served as visual effects supervisor for James and the Giant Peach.
■ Interview: Dorne Huebler, Industrial Light & Magic, San Francisco 35 (At the time of this writing, ILM was transitioning from Sabre, a modified version of Flame/Inferno, to Nuke.) LL: You’ve been involved with visual effects work for close to 30 years—long before the term digital compositing was used. Can you describe the route you took to ILM? DH: While at school at Cal Arts, I was doing graphics for commercials and titles with visual effects.… I didn’t run an optical printer.
36 chapter 1 ■ Setting Up a Composite Interview: Michael Coleman, Adobe, Seattle, Washington Michael Coleman graduated with a degree in business economics from Seattle University. He went on to work as a graphic designer, visual effects artist, and compositor for such companies as Aldus and Will Vinton Studios. In 1999, he joined Adobe and helped redesign the Adobe Creative Suite. In 2007, he became the product manager of After Effects.
■ Interview: Richard Shackleton, The Foundry, London 37 LL: There is a great deal of competition when it comes to compositing software. How does After Effects differentiate itself from the pack? MC: After Effects is surprisingly easy to use and has a great deal of flexibility to handle a broad range of projects. It integrates very well into broader workflows, and it’s almost guaranteed that the people you hire already know how to use it.
38 chapter 1 ■ Setting Up a Composite Nuke 5.1 logo LL: Nuke was developed in-house at Digital Domain. Describe the path it took from Hollywood to The Foundry. RS: Nuke was [written] as a command-line image-processing program.… [In 1993,] it was used by Digital Domain on the film True Lies. The first version, [which] became Nuke 2, was created to read scripts, draw, and show data flow down the tree. It was used for Titanic and the T2 3D ride along with many other films.
■ Interview: Richard Shackleton, The Foundry, London 39 LL: Nuke is designed for a feature film production environment. Do you consider the core client to be visual effects professionals? RS: The core client is visual effects professionals, supporting artist and production needs in feature films, commercials, CG animation, and high-value television drama and documentaries. Additional Resources: The Full Interview To read the full interview with Richard Shackleton, see the Interviews folder on the DVD.
