Issue link: https://digital.copcomm.com/i/309120
46 CINEMONTAGE / MAY-JUN 14 46 CINEMONTAGE / MAY-JUN 14 TECH TIPS by Joseph Herman R otoscoping is a critical component to every visual effects project. You may need to cut out elements from their backgrounds, merge computer-generated imagery with live-action backplates or chroma- key actors that were shot in front of a green screen. Whatever it is, rotoscoping and generating hold-out mattes play a major role in effects-laden motion pictures. However, if you don't have the right tools, roto work can be a mighty labor-intensive process. It was for this reason that Silhouette was created, and roto work remains at its heart. However, there's a lot more to Silhouette than rotoscoping. Some of the other exciting features of the program are top-notch morphing abilities, warping, planar tracking, non-destructive painting and impressive stereoscopic tools. I recently sat down with Silhouette V5 and was impressed by its advanced toolset, which has been used on major feature films by leading effects houses. For example, Framestore used it on the multi-Academy Award-winning movie Gravity and helped Weta to create the astonishing visual effects on The Hobbit: The Desolation of Smaug. ADVANCED ROTOSCOPING TOOLS Silhouette offers many options to isolate objects and cut mattes for your images. The curve tools include B-Splines, X-Splines and Bezier curves for making complex forms. Naturally, you can also make simple shapes such as circles and squares. You can combine or exclude masks to make compound shapes or group a bunch of them together in a layer group to scale, rotate or move them all at once. Recently, I worked on a shot of an old stone gothic-style building (see Figure 1). I needed to cut out a complex iron gate. Compared to some other applications, rotoscoping the gate in Silhouette was easy and elegant. The tools seem intelligently designed and the program has a very tactile feel to it — important for an artist's tool. In addition, my preferred way to create curves is by using X-Splines, which is one of the curve types available in Silhouette. You can also do important things like blur, shrink and grow masks as well as change their stroke widths. Spline masks can also have natural-looking motion blur applied to them and you can adjust such motion blur settings as shutter angle, phase and the number of samples. You can also feather splines at arbitrary points along its edge with the easy-to-use feather tool. An interesting new feature in Silhouette V5 is the ability to add IK (inverse kinematic) chains to masks. Inverse kinematics is a technique often employed in 3D character animation, where it is used to animate skeletal and joint systems in characters (see Figure 2). In Silhouette, IK hierarchies are made simply by parenting masks to one another. Silhouette then automatically creates bones from the positions of the masks. I haven't seen IK used in the rotoscoping process before, but I think it's a good idea that will help speed the often tedious process of roto work. MORPHING AND WARPING When I heard about Silhouette's sophisticated warping and morphing capabilities, I was excited. In fact, I was very excited. Why? First, a little backstory. At the time I started in visual effects, sometime in the 1990s, the effect known as morphing was all over the place. Everyone seemed to be doing it. In case you don't Roto, Morph, Warp and More THE ADVANCED TOOLSET OF SILHOUETTE Figure 1: You'll find advanced rotoscop- ing in Silhouette V5 and a whole lot more. CineMontage_May-Jun_14-3.indd 46 4/15/14 2:57 PM