Furnace Plug-Ins for Apple Shake

The Foundry Speeds Tedious Compositing Jobs

The Foundry’s Furnace plug-ins are available via tabs withinthe Apple Shake interface..

The Moving Picture Company not only provides telecine, editing, andcompositing facilities to the advertising, broadcast and musicindustries, but it also designs and creates CG animation and digitalvisual effects for television and feature film. Within MPC's filmdepartment, we do most of the 2D compositing work on Apple's Shake. Oneof this compositing system's prime benefits is its open architectureand the resulting availability of third-party plug-ins.

The Foundry, the company that creates Tinder plug-ins, alsodeveloped a set of Shake plug-ins called Furnace. The Foundry designedthe Furnace plug-in set to make some of the more tedious jobs —like wire removal and sequence stabilization — easier and faster.The full Furnace set includes Wire Removal, Rig Removal, Steadiness,Deflicker, Degrain, Regrain, Kronos (a sequence retimer), and threetexture replication plug-ins.

We first took a look at Furnace early last year, when it was stillin development. The wire-removal plug-in was the first one we tried outon Highbinders, a Jackie Chan film. Out of more than 500 effectsshots we were doing, around 250 of them included wire removal. Many ofthe shots involved extreme camera moves with fast action and multiplewires. The wires went over almost every difficult background imaginable— smoke, water, moving trees, moving people, and most challengingof all, close-up shots of faces.

Standard wire-removal tools tend to drag pixels in from either sideof the wire. Although this method is effective in some situations, itcan leave a subtle boiling of the image where the wire used to be. Inone wire-removal shot we did, the character's face filled half of theframe with a thick wire moving slowly to and fro across the face. Giventhe shortcomings of existing tools, this kind of shot could potentiallytake two weeks to hand paint.

We decided to try the Furnace wire-removal tool. To be honest, weweren't really expecting it to help, but on this type of shot, anythingwas worth trying. Training time was about five minutes, and then theoperator was up and running. After doing a test over 10 frames or so,we were amazed to see that it was working. Over the whole shot, itmanaged to do about 80% of the work, and then a bit of paint touch-upwas needed. This saved the operator more than a week's work.

Furnace is easy to use; just place the markers at either end of thewire, set the wire thickness, and the wire disappears. There are a fewdifferent repair options, depending on the type of wire and background.When Furnace removes the wire, it examines the texture of thesurrounding background and tries to replace the wire with that,retaining detail but leaving the film grain and eliminating the need toregrain the area afterwards. If an object passes in front of the wire,the object will remain untouched while the wire on either side is stillremoved. There is also an option to track the wire automatically, butwe usually did it by hand.

During the course of the Highbinders project, we saved a lotof time using the wire-removal plug-in. It is so quick and easy to usethat we could try it out on a shot and know instantly if it would work.Soon, all of the wire-removal operators were trying it out on everyshot, and in the end, they used Furnace to remove about two-thirds ofall the wires. It did a fantastic job on shots where wires went overdust hits, clothes, or skin and in shots with fast camera moves. Itstruggled, however, on shots where the wire went over a regular,patterned background, like brickwork. As a result of our feedback, TheFoundry has included an option in the wire-removal tool to deal withthese scenarios. Additionally, the rig-removal tool will do a great jobon these types of shots.

On Highbinders there were also a lot of shots that requiredretiming. Shake doesn't have a high-quality retimer, and thealternative was to use Cineon's Cinespeed. We were keen to avoidpotential bottlenecks in our workflow, so we decided to try Kronos, theFurnace retimer available to all of our Shake operators. After tryingit out on a couple of shots, we were surprised to find that it gaveresults just as good and sometimes better than Cinespeed.

Instead of doing a frame-blend like the current Shake retimingoption, Kronos analyzes the motion of the sequence, and then createsnew frames where needed, yielding smooth results. There is no need towait for several hours for the image analysis before you discover if ithas been successful; you can change parameters and get instant feedbackon any frame so that you know you have the settings right beforesending it off to be processed.

Further, Furnace's degrain and regrain tools have improved immenselyover the alpha and beta phases. The degrainer works at three differentlevels to remove different sizes of grain and does a great job ofretaining image sharpness and detail. The regrainer analyzes grain froma frame of the sequence and then uses this information to createunlimited new grain, which can be added to CG objects, helping them fitseamlessly into the shot.

There are also three texture replication tools that we have not yetused on a film, but they look interesting. They can replicate finetextures, such as grass or water, in order to remove objects from ascene, or they can work on larger textures, such as a crowd of people,if you want to make your 200 extras into a thousand. The clever thingabout Furnace's texture tools is that they tile in such a way that youcan't see the join between the repetitions, which also makes themuseful for quickly creating a single frame of tileable texture.

Many of Furnace's tools require motion analysis on a sequence. Thiscan make it fairly slow to get results, but by working with croppedareas of the image, it is possible to work on film images and getacceptable interactive feedback. The wire-removal tool will work onlyon wires that are straight or nearly straight. Although you can alwaysdivide a curved wire into sections, it would be great if The Foundrydeveloped the tool further to deal with this situation more directly.There will always be scenarios that the plug-ins can't successfullysolve, but at least you discover that quickly, so time isn't wasted onsomething that has to be redone.

The Foundry has kept the tools flexible, which means it is sometimespossible to use them to solve a problem partially. One example of thisis the wire-removal tool where, if all else fails, you can still outputa matte of the wire and try to fix the wire another way.

Overall, Furnace has gone beyond plugging some gaps in Shake'sfunctionality. There is some pretty clever stuff in here. I'm in favorof any tools that reduce the time spent on tedious jobs and allowcompositors to be more creative.

Angela Barson is senior compositor at The Moving Picture Company,a post-production facility based in Soho, London. Recent film creditsinclude Harry Potter and the Chamber of Secrets, for which MPCwas the lead facility. MPC is currently working on a number offeatures, including Lara Croft Tomb Raider: The Cradle of Life,Octane, Cheeky, Blackball, Ella Enchanted, and Calendar Girls.For more information, please visit www.moving-picture.com.