Anita18
DANCE FOR ME, FUNNY MAN!
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This is rather old, but I haven't seen it posted here, so I'll do it. 
http://features.cgsociety.org/story...mage&utm_campaign=20080728&referer=newsletter
I could tell that the wide-angle ferry shots, the exploding helicopter, and the Pruitt building shots were digital, but I had no idea about the exterior penthouse shot and the Batpod emergence. If I understood the article, all of the shots of the Batpod turning corners were also digital. Those were very well done.
And
at the resolution and computer power they were working in.
It wasnt just a blockbuster success on its opening weekend. It wasnt just the bigger than life comic book characters. It was creating and rendering the bigger than life IMAX resolution that the team at Double Negative accomplished so flawlessly, a task that required a complete overhaul of the pipeline. For roughly 365 days, the digital FX of The Dark Knight was FX Supervisor Paul Franklins first task.
Returning for an encore from Batman Begins, Franklin and the FX team had the advantage of knowing director Christopher Nolans style and expectations, but the format added a quite a few additional twists. The biggest difference between Dark Knight and Batman Begins is Batman was entirely shot without anamorphic lenses, its all made in cinemascope. The majority of Dark Knight was shot in cinemascope but a substantial proportion of it originated in IMAX format, and we did all the post production in IMAX resolution, a major R&D effort, said Franklin.
When plied for further explanation, Franklin offered the following: There was an IMAX release of the film, but this was achieved through the DMR up-res process in which standard 35mm is expanded to fill the full width, but not the full height, of an IMAX screen. The Dark Knight is the first major feature film to be shot using the native IMAX format, 65mm, 15 perf, though it's actually only parts of the film that were shot in this format; five major sequences in all. The rest of the film was shot in standard 35mm cinemascope. The cinemascope sections of the film have been expanded with the DMR process to work in IMAX theatres.
The first thing DNeg tackled was the compositing systems, based around Shake. Compositing packages tend to become unstable beyond 3K, and anything beyond 4K creates an unacceptable failure rate. A package like Shake with a 32 bit internal architecture can only look at a certain amount of memory, so even if the computer has 16 gigs of RAM, Shake can only address about two gigs of that memory space. To resolve this, DNeg built their own 64-bit compositing pipeline. The next big challenge was optimizing the rendering times by implemented so many shader and rendering improvements that even at 5.6K, which is what most of the film was rendered at, were comparable to the render times on Batman Begins, which was rendering at 2K.
The real limiting factor on the whole exercise was actually nothing to do with render power or even the compositing. It was more that the fact the images occupied so much space on disk that it was difficult to install enough servers into the building to be able to hold all the data. A single frame of IMAX, at 8.4K full resolution is 200 MB of data, whereas a standard 2K frame is 10 MB of data, so its 20 times the size of a standard frame. That totals to roughly 100 terabytes of storage. That was all in-house. Our tech team had a pretty long lead-time in all of this, so they started bringing in major infrastructure upgrades, buying new servers, optimizing the power flow through our machine rooms to be able to accommodate this vast amount of additional storage. We had an extra bonus out of this.
We upgraded our render farm so it used less power so we could use the spare power to run the additional disks that we were putting into the building. That was actually ultimately the final limiting factor, how much electricity can you get into a facility! It was quite an awesome exercise. What was even more extraordinary was that the pipeline worked so efficiently, Franklin couldnt recall a single overnight render failing until the very end of the show when Hellboy 2 was sharing the pipeline at the same time. For me, thats kind of unheard of. I normally always expect to come in to look at overnight renders and see dropped frames and things like that, but it never happened, it was that slick, it was very, very cool. An early test was the IMAX mini-movie of the opening bank heist released last fall, introducing the Joker and containing roughly six FX shots. Though completed at the full 8.4K resolution, the decision was, visually, there wasnt really enough difference from 5.6K, so they down-resd the remainder of the IMAX work.
During production on Batman Begins, Franklin and his team created an architectural library of nearly 40 Chicago buildings, but they were designed to work for night time shots and to hold up to within 50 or so feet of the camera. Below that, resolutions began to break down. Unlike Batman Begins, Dark Knight had several daytime and twilight scenes, requiring the library to be refurbished and expanded. Franklin decided that, rather than baking in the lighting textures that pertained to one time of day, they would re-photograph all of the textures under flat lighting conditions. By doing this, the camera could come within 10 feet of the surface and the textures would still hold up. It produced a very flexible library of buildings that allowed them to create one architectural library to relight in any of the required conditions.
This library proved invaluable for some of the work DNeg had to seamlessly integrate into the live action, such as in the Pruitt Building sequence, derived from live action footage filmed at the Trump Tower, which was still under construction. Director Chris Nolan wanted dramatic angles on the building, something unavailable in the plates. The team did a very careful documentation of the partially constructed Trump Tower, and working with the LIDARed effects, digitized the building and built it as a detailed model. The big deal was none of the sides were on the Trump, they hadnt added the glass at this point so all the internal stricture of the building was visible, you could see right through it, and all the cement mixers and spools of cable, and girders and support jacks all visible inside it. But we had to build it to work at extreme wide angle shots to extreme close-ups.
The shots inside the building are actually on set in the UK, using a huge green screen in an old aircraft hanger with a nine story building set inside. The windows of this building looked out to the green screen, which DNeg filled with high res digital vistas of Gotham City. We used our panoramic photographic process, but also did a lot of digital architecture because there wasnt any one landscape we could use in Chicago to actually place in these different views. So there is an awful lot of green screen compositing and very careful keying that had to be done, all at IMAX resolution.
One large scope sequence was set inside Bruce Waynes penthouse apartment, shot in the lobby of the Illinois Plaza, a sky-scraper in Chicago. One of the biggest is the penthouse engagement party Bruce Wayne holds for his former girlfriend Rachel Dawes who is now engaged to character Harvey Dent. The party starts in the early evening with a large establishing shot of the building exterior, a fully digital skyscraper with the penthouse on top. The view then switches to inside the penthouse looking out across the dusky landscape of Gotham City created from a series of very high res digital matte paintings.The end of the party is in full nighttime, and ends in chaos at the hands of the Joker, who takes Rachel hostage and pushes her out a window. Batman throws himself through the broken window after Rachel, grabs her hand as she slips off the edge of the roof, and they both go over together, dropping in freefall down the side of the building. At the last moment, he manages to pop out one of his batwings, and they spiral down, crashing onto the roof of a taxi, saving her life. This whole sequence involved full digital environments and digital stunt double work.
The scene where the Joker is trying to take out Harvey Dent while traveling in an armored car begins as practical effects then switches to digital. The Joker is armed with a rocket propelled grenade launcher, and hes firing grenades at the police and SWAT vehicles, attempting to take Harvey out. By firing the Batmobiles rocket engine, Batman is able to maneuver in between the Joker and Dents armored car just in time. The rocket hits the Batmobile, blowing up the rear end. The Batmobile hits the ground and tumbles. Inside, Batman is desperately trying to get the car restarted, with the camera pushing in.
All of this was a practical stunt, but when the front wheel begins to spin and start skidding the entire car around, the scene switches to digital. Back and forth from digital to practical, with interior shots of Batman trying to get the car started and exterior shots with plates retracting, revealing the internal structure and two fat front tires. Finally all the panels blow off the outside of the Batmobile when explosive bolts are fired. The front two wheels of the Batmobile swing around and lock into place, forming the front and rear wheel of the bat pod, the motorcycle, which leaps out of the wreck of the Batmobile. Batman then tears off down the road to continue the chase. All of this sequence had to be done digitally because there was no way to engineer this transformation on the set.
"Wed done digital batmen, digital stunt doubles for Batman Begins, but never had to do anything seen this close up under this degree of scrutiny, explains Franklin. The guys really rose to the challenge. The hand over between the practical and the digital Batmobile is absolutely seamless. The only thing people will perhaps find as a giveaway is, how would you actually get all that to work? But hopefully weve given it enough mechanical reality that it pulls all together. This is a good example where Chris would say, we dont have anything here, what are you going to do for me? This usually happens when we have about four weeks before delivery, so we are well into the post period, the film has all been cut together, then you are looking and see there is a big black hole there, and Chris says yes, we need a shot of the Batmobile doing this. Well, what about a background plate? Oh, there is no background plate you have to make the environment as well. So we not only had to do the Batmobile and Batpod and Batman, but the entire environment that the Batpod drives out into. But because we spent all this time putting the pipeline to get the assets in place, and fully documented all the locations and sets, we could do this.
Since the practical Batpod steering wheel was limited to a deflection of roughly five degrees, anything as basic as cornering had to be done with the digital version.
Director Chris Nolan loves to do his work in camera, only adding in digital effects when there is no other way to accomplish the scene. As with the transition to the Batpod, the helicopter explosion chase scene needed to seamlessly cut back and forth. Using grappling hooks to create an impromptu web stretching across an urban street, the Jokers henchmen ensnare the police helicopter as it pursues the Jokers semi-truck. As ever, Chris, wanted to do this practically if he could, but obviously there are limits. And though Chicago was very happy to let us do all sorts of crazy things in the street, they werent that keen on us crashing a helicopter into a building. Using a practical fuselage packed with explosives, hooked to a steal cable and pulled 8by a vehicle, the special effects crew was able to provide the explosions and helicopter flipping down the street. But in the helicopters approach to the web, the scene is fully digital, including the environment. So is the scene where the chopper spins out of control and crashes into the building.
Using Double Negatives in-house Dynamite to animate the scene, and adding additional tool sets to create realistic looking patterns in the shattering glass, the CG fireball creating a highly convincing deck explosion. We used a combination using Maya fluid dynamics and Squirt, our own fluid dynamic system, and rendered with DNGB volumetrics to give the big fireball. There is a lot of painstaking compositing to integrate all these elements together. Hopefully people cant tell as it switches between completely digital, combination digital and live action, then live action.
http://features.cgsociety.org/story...mage&utm_campaign=20080728&referer=newsletter
I could tell that the wide-angle ferry shots, the exploding helicopter, and the Pruitt building shots were digital, but I had no idea about the exterior penthouse shot and the Batpod emergence. If I understood the article, all of the shots of the Batpod turning corners were also digital. Those were very well done.
And
at the resolution and computer power they were working in.
