Assessing Previs

The American Society of Cinematographers, the Art Directors Guild and the Visual Effects Society join forces to explore the existing and potential uses of previsualization.

The perception of previsualization as a time to experiment raises still more questions, including how finished previs materials should be. One topic of discussion in the Previsualization Committee has been whether the CG models made in previs can or should be constructed in such a way that they can later be handed off to a visual-effects facility and used as the basis for the final effects. “There’s always someone who believes he can set up this amazing pipeline and integrate previs and effects, but right now, you can’t do that,” notes Nic Hatch, owner of London previs facility Nvizage.

According to Hatch, the different goals and needs of the two departments make it difficult to combine them. Previs is concerned with timing and framing, and the models and character rigs are very simple; they have a limited number of controls so they can be easily manipulated in real time, with no rendering. By contrast, artists making visual-effects shots that will appear in the movie have to create photorealistic images, so their models and characters need to be complex, fully textured and rendered out, making them very difficult to work with in real time. “I like to think of previs companies as speedboats: We’re very fast and can change direction easily,” says Hatch. “A post house is like an oil tanker: It can carry a lot, but when it switches its engine off, it’ll cruise for two miles before it can stop.”

Please click here for the full article: American Cinematographer

Chas Jarrett on Sweeney Todd

Estelle Shay chats to visual effects supervisor Chas Jarret about the process of recreating the gritty and squalid  Victoria-era London seen in Tim Burton's moody Sweeney Todd, in the latest Cinefex magazine 113. 

Extensive previz, led by previz supervisor Martin Chamney, also proved invaluable in designing the look of shots and determining the scale and scope of the environmental work. "The previz  really helped us to understand the size of the London we were going to have to create, and allowed us to choose the best methods. For me, it was also a very technical resource. We did a lot of technical previz where we would take a sequence that was going to be a CG environment, and create reams and reams of printouts for the art department on set, so we could mark the floors and figure out what world was going to be around you when you were standing on a greenscreen stage."

The First Hero

Take a look at Jody Duncan's article on realizing Roland Emmerich's 12,000-year-old world in 10,000BC in this quarters Cinefex magazine 113.  It details Nvizage's role in guiding the on location filming and how their robust, long-term pipeline played a crucial part in creating such extensive and detailed previz and post-vis with a team of up to 20 artists.

Nvizage and Visual Effects Supervisor Karen Goulekas had thoroughly prevized the terror bird sequence, and had included in that previz a detailed CG environment. Emmerich so liked the previz environment he had elements of it recreated in the practical set. "We had also let the animators go to town coming up with sight gags for the terror bird attack," recalled Goulekas. "They had tree branches snapping and falling on the birds, rocks hitting the characters. It was really a fun sequence to previz...."

Click here for more information about Cinefex.

10,000 BC Previs

Creating life is just not as easy as it used to be, especially when you can practically feel its breath on your face from a high def image 80 feet wide. But this was the task for the VFX teams on 10,000 BC with its stampeding mammoths, a saber tooth tiger, vultures, a flock of terrorbirds, and thousands of digital slaves.

Goulekas decided to skip storyboarding and jump directly to previs. To assist with this, she recruited Nvizage’s Nic Hatch and Martin Chamney and requested a team of 14 character animators, four asset builders, modelers, texture painters, character riggers, and a visual effects editor.

Please click here for the full article: CGSociety

Sweeney Todd: There Will Be VFX

If ever there were a musical tailor-made for the twisted, Goth-inclined tastes of director Tim Burton, then surely it would be Stephen Sondheim's equally dark and twisted musical, Sweeney Todd: The Demon Barber of Fleet Street. While it's certainly a departure for Burton to adapt a stage-originated musical for the big screen, Sweeney Todd does manage to incorporate some of the director's signature themes such as death, lost love, the exploration of social status, absent parents and the hero as outsider.

TDB: Did you have to previs a lot of your settings?

GB: Yes, there was a small previs team in place from Nvizage throughout pre-production and on into the shoot. On certain shots, it was really instrumental and drove a lot of what was filmed. There was one shot, in particular, where we fly through the city at a real pace, which is essentially a full CG shot, with moco elements for the people. The previs drove this from the start. On others, it may have just allowed Tim to explore some ideas before rocking up on the day. It was rare that the previs was literally shot, as is the norm, but it's a very effective pre-production tool, as it can help raise issues creatively and technically that may have only come up too late when the cameras are about to roll. In that sense, a lot of the work was technical previs to inform the builds of the greenscreen stages.

Please click here for the full article: Animation World Network