Client: The Sex Pixels in association with Escape Studios
Visual Effects Supervisor: Adam Thomas
Sequence Supervisor: Mark Pinheiro
Project: The Hunt For Gollum - Independent Feature Film

When latex prosthetic masks worn by several actors were wrinkling so noticeably that several important shots from the highly acclaimed independent production, The Hunt For Gollum, were in real jeopardy, something had to be done to rescue them. Offering to help, Escape Studios tutor, Mark Pinhiero, had an idea that using PFTrack might offer a quick and relatively painless way to solve the problem. In conjunction with several trainees at Escape, all working under the aegis of third party company The Sex Pixels, he tested his idea with the application and it worked like a dream.

The Hunt for Gollum is an indie film produced by Independent Online Cinema, and directed by Chris Bouchard. Released worldwide on 3rd May 2009, the 40 minute film is set in Middle Earth shortly before the events of The Lord of the Rings. Produced collectively by a small army of talented volunteers and amateur enthusiasts, it centres on Gandalf and Aragorn's efforts to keep the ring a secret. Shot in the UK at locations in Epping Forest and Wales, the film has drawn worldwide interest not only because of the its association with The Lord of the Rings, but largely because, for a feature of this genre, it displays a very high level of professionalism in its execution and maintains production values more usually seen in multi-million dollar movies and not the mere 3,000 (under $5,000) that this production cost.

Offering assistance for any post-production needs on the project, Mark Pinheiro was pleased to be duly issued with several Roto shots for Matte painting Composites for the trainees at Escape to practice their skills on, but asked if there were any other jobs he could challenge his team with and was presented with an important sequence that establishes the character Aragorn as a hunter. Unfortunately the scene was marred by the latex masks actors playing Orc characters were wearing, which wrinkled visibly with movement. Up to this point nobody had wanted to tackle this problem, mainly because it wasnt a straightforward 2D solution due to the way the actors heads moved in 3D space. Mark Pinheiro explains, "They asked if we could take a look at cleaning up the Orc's Latex Mask wrinkles that formed around the cheek and neck whenever the actors spoke. I could see why 2D artists were avoiding it as the Orc's rotate their heads around the Y axis and therefore move the wrinkles back and forward into Z Space which would require a 3D solution of some kind."

The team at Escape tested a number of softwares with the problem, and concluded that PFTrack was the most capable of performing the tasks they would be asking of it, as they would be utilizing the application in a slightly unconventional way. In addition PFTrack is available for Linux which suited the pipeline they were using with Shake, and for trainees they found that it was by far the easiest software to use. But really it was its unique Geometry Tracking feature and ability to object track that clinched it.

The Geometry Tracking function of PFTrack allowed the team to import a CG mesh of the Orc characters head and accurately track it onto the live action head. As this was the only element that the team was interested in for face clean-up work, they required PFTrack to object track it within the plate. Mark Pinheiro had already tried to simulate a 3D move on a patch like this in Shake using a warp node, and also in Nuke using a projection technique, but found that PFTrack made the process much easier. He explains, "Every shot was handheld yet we disregarded the need for a scene solution and told PFTrack every shot was stationary as we were projecting from the camera and so the mesh didn't require a specific Z position. Using a very generic mesh that Rosie (Rosie Chester, 3D Artist) modelled for all of the Orcs which only included some detailed modelling to describe the eyes and the nose features, we object tracked this in as a second motion. Against everybody's advice, it seemed to track in rather well, with only slight resizing or extruding of the mesh needed depending on the changing focal lengths of each scene."

In this way they effectively tricked PFTrack into thinking the shot was a stationary lock-off, and the object alone was moving within the camera so that accurate data of the object movement produced by PFTrack could be used within Maya allowing a texture to be applied seamlessly. Once the data had been exported to Maya, the geometry they didnt need could be deleted leaving just the patch they were interested in to project the texture, render it and export to Shake for final compositing.

What really surprised the team during the whole process was PFTracks ability to identify the moving object within the plate, even on just auto settings and across shots up to 400 frames long. With no budget there was no head scan leaving the team to work with very basic geometry. Mark Pinheiro comments, "The lack of detail in the mesh we thought might be a problem in determining whether it would object track with the footage". However, PFTrack performed beyond everyones expectations. "We didnt even need to matte out areas of the plate we didnt need. PFTrack was amazing, it just latched onto the object with just the help of a few keyframes. And thats despite our imported geometry being quite rough", says compositing trainee at Escape, Davey Atkinson.

For all the team who worked on this project at Escape Studios including 2D artists with only eight weeks compositing experience, it was a very steep learning curve, but their enthusiasm and dedication to making the solution work is both commendable and indicative of their emerging skill and aptitude. Director Chris Bouchard and VFX Supervisor on the movie Adam Thomas were so impressed with their work that once the face replacements were out of the way, as a reward for all of their hard work they gave the team the opportunity to composite their own roto-mattes for the Multi-Plane Matte Painting Composites producing around 30 shots for the film.

Mark Pinheiro sums up his experience of PFTrack as both a user and as a teacher, "We started using PFTrack for both scene and object tracking. I'd used other tracking software but they didn't offer the same functionality so I opted for PFTrack." He says before offering an example of some its powerful functionality he is particularly impressed by, "Automatic lens distortion detection is unbelievably helpful and services our entire pipeline. Being able to export footage that has been un-distorted and then re-import after compositing to put the distortion back on is a godsend. The Pixel Farm also allowed me the opportunity to buy a teacher license and the opportunity for students to acquire that kind of technology at a Student price is nothing short of generous."

For more information about the film, visit: www.thehuntforgollum.com
For more information about Escape Studios, visit: www.escapestudios.com

Words: Martin Southwood