TECH TIPS
NonlinearEditing in 3-D
by Paul Peszko
 Graphical User Interface of Softimage XSI. Courtesy of Softimage |
The explosion of 3-D animated entertainment has made possible the proliferation of a host of 3-D programs, all jockeying for prominence and trying to out-feature each other in an effort to capture producers of all sizes and budgets. Among the latest incorporations are nonlinear motion and scene editing systems. Just how functional are these systems and exactly what can they accomplish? To answer this question, Editors Guild Magazine spoke with 3-D software developers and users alike and found that the differences in opinions could be a matter of semantics.
Some 3-D software manufacturers gear their products toward the pure animator and provide little in the way of nonlinear editing systems. Of those that do incorporate NLE systems into their software, most are very comparable in functionality when it comes to nonlinear animation. The differences lie mainly in user interface, training and sound editing capabilities.
In the past, Discreet’s 3ds max® has used a plug-in, called character studio 4, and purchased separately to allow for nonlinear editing. The system is a function of Biped, the largest part of character studio 4.
Ian Nies, the product designer for character studio 4, describes Biped as “a parametric rig.” He explains that it is character primitive, which comes in default in a bipedal form like a human being, but it can also be manipulated into being quadrupedic.
Dan Prochazka, product manager for character studio 4, adds, “One of the things to understand at the higher level is that Biped is tailored specifically to doing nonlinear animation of all characters. I think that’s really where its strength lies. It works in a lot of ways just like A-B roll editing. If you have a clip that you’re trying to edit, you create a transition to the next motion. One of the most powerful things about it is the ability to blend in parts of motion.” This feature is called “dynamic propagation,” which makes body part mixes look natural and coherent.
Nies explains how dynamic propagation works: “For instance, if you have a flailing upper body and a calmly walking lower body and you put those two together with no influence, it’s going to look kind of funny. Well, character studio 4 will intelligently interpolate between those and let the upper body influence the lower body so that the hips start to shake and things like that.”
In general, the character studio 4 mixer provides a constraint-based mixdown, so the system has all the constraints, joint angles and limitations of a Biped built-in. In addition, the system provides motion capture prop re-targeting, where the props are now treated as part of the Biped itself, resolving what had been a major problem for the mocap (motion capture) and games industry.
With 3ds max® 6, users no longer have to purchase character studio 4 as an optional plug-in. Instead, all of its components, including Biped and its nonlinear animation system, are included in this latest version.
At SIGGRAPH 2004, Kaydara showcased MOTIONBUILDER 6. As in past versions, an animator will be able to layout audio, video and animation data into a timeline with MOTIONBUILDER’s nonlinear editing system, known as Story Tool. The real enhancement, however, comes in having a separate camera track.
“One of the greatest strengths of MOTIONBUILDER 6 is that you have
a separate camera shot that allows your editorial work on top of your layout
track,” states Michel Besner, president of Kaydara. “If you have
a character walk into a room, close the door and perform some specific action,
you will most likely have different cuts in that sequence where you will move
forward or backward in time. So, it’s not a continuous timeline once
you’re editing,” he explains.
“The value we’ve added in MOTIONBUILDER is that it allows you
to do your cuts for your camera shots separately from your animation track,”
continues Besner. “You can actually do editing of your camera cuts without
having to work with your animation data. This is a true editing environment
for doing time discontinuity between your camera shots.”
The self-contained editing system included in Maya 6 is called Trax, an acronym for time-related action. Trax was the evolution of the long-standing philosophy at Alias and Maya to give an artist the ability to manipulate and handle complex data in simplified and artistic ways.
“So,” explains Shai Hinitz, product manager for Maya at Alias, “If we take a typical situation of a Biped, and we break down the entire character to the head and the upper torso––and that upper torso breaks down into the separate arms, and we keep going down to the pelvis, legs, feet and so on––we have about a dozen tracks now for that character. We can start placing clips that represent performances on the different areas. The way it’s set up is that it can be expanded and collapsed as needed. So, for example, you might have mocap data of an entire human character walking, and that can be one single clip. And you can apply that one single clip to the entire character at the same time.
“But, let’s say you wanted to have that character wave at the camera during the walk process,” continues Hinitz. “Then, you can apply a separate clip just to the arm while the rest of the body still has the mocap driving it. And, if you don’t like where the clip of the hand waving is taking place, you can always slide that back and forth in time to get the exact performance you want to get.”
Softimage is another major player in 3-D software. “Way back when we set out to design XSI, I guess we were the first product to market with any kind of high-level nonlinear editing for 3-D animation,” says Gareth Morgan, senior product manager for Softimage. “So, we consider ourselves the pioneers in that area. One of the great things that comes out as a result is the fact that XSI is designed from the ground up around nonlinear, nondestructive editing.”
 Dragonhead designed and rendered in messiah:studio 2.0. Courtesy of pmG Worldwide LLC |
Over time, Softimage recognized the need to evolve controls that provided for easier user interface of enormous data. “They [users] really need to be able to selectively group together chunks of animation for a given limb or a given character within the environment and then abstract those groupings of animation data down into such clip entities, which provide a very simple nonlinear editing style interface to control them,” Morgen continues.
“We’re not just talking about key frames here. A lot of what’s in 3-D scenes is expressing relationships, or what we call constraints, that directly connect two objects with some kind of functional relationship. You also need to control those time spans and join them together. As soon as you get to that level, then you need to be able to do all sorts of other things that you typically do with a nonediting timeline as well. So, along comes fades and blends and transitions.”
In addition, pmG Worldwide LLC has two products: messiah:animate 5.0 and messiah:studio 2.0, a full suite, which contains messiah:animate and the company’s new renderer. Both have a self-contained, all-original NLE, called Compose.
Lyle Milton, a partner in pmG Worldwide LLC, says that Compose’s two main features are ease of use and consistency. “It’s as simple as you want to get and as deep as you want to get,” he explains.
Milton also indicated that Compose gives an animator control over the clip, individual elements in the clip and individual channels in a clip. This allows for changes in character expression and scripting. It also enables such things as pitching and bank rotation as part of the animation mix. “It’s pretty easy to use and straightforward,” he says. “So far, in the feedback that we’ve been getting when users compare it to different systems, they find it becomes a lot more intuitive over time, because of the way that we’ve designed consistency into the entire system.”
Only two of the programs, Maya and XSI, had any sort of advanced sound editing capabilities. Although not as extensive as sound editors like ProTools and Nuendo, they do add to the overall pre-visualization––or pre-viz––of a scene. Both Maya and XSI offer the ability to have multiple sound clips and move them around for lip-synching or timing precise sound cues.
Across the board, professional animators working in both studio and independent features as well as video games indicated that they rarely use the NLE systems that are incorporated in their 3-D software, or have only used them on a shot-by-shot basis for very short pieces. When it comes to any type of long-form animation, they concur with the philosophy expounded by Eric Huelsman, president and CEO of Studio Arts, Ltd., a Guild-approved training center for professional animators and editors in Los Angeles. He feels that using a specific editing program or a professional editor is the way to go.
Says Huelsman: “At Studio Arts, we’ve evolved a philosophy of using a nonlinear editing system for nonlinear editing and using 3-D software for 3-D. If there’s a need for editing, by all means, we’d want to use an editor to do it, and some good NLE systems like that are Final Cut Pro or Avid Express. They’re very low-cost, and a lot of people use them.”
Kevin Geiger is a veteran Hollywood animator, who has worked on both studio features and smaller independent shorts. When working independently, he uses a separate editing package to avoid confusion. “When you’re doing some non-linear editing in your 3-D package and then doing further editing in Premier, you can get into a situation where it becomes convoluted,” he explains. “It’s easier to manage it all in one package [like Premier].”
His advice is much the same as Huelsman’s. Talking about his work on short independent films, the latter says, “You can deal with it [nonlinear editing] all, sort of holistically in terms of background plates and so forth, and all those different levels, in After Effects, or in Premier as opposed to [the editor] in Maya’s 3-D package.”
So, if animators aren’t very inclined to use the NLE, why are software manufacturers still incorporating them into their 3-D packages? As mentioned earlier, it often comes down to semantics. Actually, some animators are using these editors, but not for nonlinear editing in the traditional sense.
“The idea is not so much that it’s NLE as you’re used to with video,” explains Milton. “It’s completely different. When you’re working with video, that’s pretty much a start-and-end product, and the goal there is pretty much to sequence these video clips and blend them together. With animation, the system is different. We’re used to thinking in terms of nonlinear animation, where you have a lot of different components.”
He believes that these systems focus on animation and character animation specifically, where the character or at least the character skeleton is already set up. Milton adds, “NLA systems allow you to take mocap (motion capture systems), apply it to that character or that skeleton and blend between different clips––let’s say a running pose and a jumping pose and a walking clip––and piece together the creative performance. A lot of systems even allow you to go further. For example, ours allows you to control the motion clip through expressions and scripts and things like that.”
Milton feels that animators are warming up to the idea of using these systems for nonlinear animation so that once their animation is in place, they can have more flexibility adding layers of motion. Time will tell whether he’s correct or not.
E-mail addresses for manufacturers mentioned in this article are: www.discreet.com, www.kaydara.com, www.projectmessiah.com and www.softimage.com.
Paul Peszko is a Los Angeles-based screenwriter and novelist who contributes to Animation Magazine. He can be reached at paul@storywerx.com.
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