Digital Video - December 2007 - (Page 19) The interface of SynthEyes allows the placement of primitive 3D objects in the scene to check motion tracking accuracy. the software selects and sets the trackers), manual tracking (where you set trackers yourself), or a combination where the user adds trackers to the automatically selected ones. I tested SynthEyes with a variety of types of footage, both SD and HD, tripod-mounted, dolly and handheld. Not surprisingly, the system performed most accurately on material that was specifically shot for 3D tracking, where there is definite movement of the camera in the scene and clearly defined tracking points. These may be colored dots or simply well-defined high-contrast set pieces. Very dark shots that do not provide well-defined tracking points will not work well; neither do very low-contrast shots. (Here’s a tip: sometimes these shots can be effectively tracked by creating a temporary intermediate file with radically boosted contrast. The footage doesn’t have to look nice to track well!) As the documents predict, SynthEyes is not at its best for 2 1/2D shots where the camera is tripod-mounted and doesn’t move physically in the scene. The same can be said for shoulder-held shots where the camera operator simply swings the camera around and doesn’t actually move from a single location. Such shots don’t give the 3D solving engine the kind of depth data it needs to actually resolve a full 3D solution to a scene. The result is that the shots track well until there is significant movement inside the frame—say a person walking across the frame-which can confuse the system and cause significant “slippage” in the scene. While SynthEyes 20071/2 includes a new single-frame 3D line-alignment tool for nodal tripod shots and lock-offs, these shots still resolve much less accurately than fully 3D scenes with good markers. You can export to After Effects through copy-and-paste of tracking data for a single tracker (for motion tracking a single object) or through an intermediate Maya file. The Maya file can include both the deduced 3D camera motion and the trackers, though including all the trackers is typically an unnecessary load on the system. After Effects’ handling of Maya files isn’t perfect, however. Export to a 3D program is much better; I tested Lightwave with excellent results. The program exports a complete Lightwave scene with the footage set up as a background composite; the modeler can position 3D objects in the scene very precisely guided by the imported trackers. A warning: though SynthEyes has an automatic tracking www.dv.com mode which performs quite well, there is really no such thing as completely automatic tracking. While SynthEyes and its competitors are very powerful and complex pieces of software, they all perform best when results are hand-checked and corrected by human eyes. Sometimes trackers wander a bit or “hook” as one object passes in front of another; this can sometimes confuse the 3D solving engine and create slippage. The scene resolution turns out much better if the operator carefully checks and corrects straying trackers prior to the final 3D resolution. SynthEyes’ developer, Andersson Technologies, has provided some good instructions on its website (www.ssontech.com) and in the user’s manual outlining how to shoot for best tracking results. The instructions are a must-read for set designers, DPs and camera operators intending to use a matchmove system. The documentation (provided as a PDF file) is quite comprehensive, though often opaque to the matchmove newcomer. The rather complex interface is not mapped out clearly, and first references to some hard-to-find windows need to have a little road map added (“This is found in the drop-down list ”) so that new users don’t have to hunt. Andersson also maintains an online discussion forum for questions. SynthEyes exports to most common 3D computer graphics and compositing packages. CGI programs include 3ds max, Animation:Master, Blender, Carrara, Cinema 4D, Electric Image, Houdini, Lightwave, Maya, Poser, Realsoft 3D, trueSpace, VIZ, Vue 5 Infinite and XSI. Compositing/2D programs supported include After Effects, Combustion, Fusion, Flame, Inferno, Mistika (new for 2007), Motion, Nuke, Particle Illusion, Shake, Silhouette Roto and Toxik (some are 2D-capable only). Scripting lets you customize the standard exports, or add your own imports, exports, or tools. SynthEyes has collected quite a list of feature film credits, including Pirates of the Caribbean: Dead Man’s Chest, Talladega Nights, King Kong and the Emmy-nominated Sci-Fi Channel feature Mammoth. It’s in use now on the sci-fi thriller Eyeborgs, currently in postproduction. In the end, the software has many features of much higher-priced packages such as PFTRack, Foundry’s Furnace, or RealViz Matchmover Pro, all in the $4,000 range, and as such represents a solid purchase value. SynthEyes 20071/2 is available for Windows XP, Windows XP Pro 64 (64-bit), and Intel and PowerPC Mac computers from Andersson’s website at www.ssontech.com. The Rev. John Jackman has been involved in video production since the mid-1970s. He is currently in postproduction on a feature that will use matchmoves for some effects. You can reach him in DV.com’s Craft of Lighting Forum. dv december 2007 19 http://www.ssontech.com http://www.ssontech.com http://DV.com http://www.dv.com
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