Freekstorm VFX Blog

In my last post I mentioned that much of Rich’s time was taken up doing horribly complicated technical stuff on the computer. It sure looked impressive but to be honest I had no clue at all what he was doing, other than it fell under the label of “previs.” As I’ve been allocated the rule of producer, I decided it was time for a bit more research.

For those of us who are unfamiliar with “previs” or “previz”, the term is short for “previsualisation” which is where scenes in a movie are extensively planned and visualized before the start of filming. The storyboard is effectively translated into artwork so that movie scenes and sequences can be meticulously planned in advance. The director can then experiment with different lighting and camera angles, and see which scenes work and which ones don’t, without having to waste costs on actual production.

Francis Ford Coppola was the first director to use previs techniques on his movie One From the Heart in 1981, although this was before the days of modern filmmaking software. Coppola and American Zoetrope designed a high-tech video-viewing centre which was housed in an Airsteam RV trailer which was called The Silverfish and which also came complete with pink interior and a hot-tub! The Silverfish was used as an audio support set and for capturing the pictures coming from the camera via a video tap. Story board artists had already been charged with drawing some 1800 drawings which were then shot and stored on an analog videodisk along with a reading of the script, where they could be instantly recalled when Coppola needed them. To this store was added extensive movie footage during the making of the film. Coppola would then examine the movie clips on video immediately after filming and use them to shape the next day's shooting. This was the first true “previs.”

But hurrah for technology! Nowadays, the process is somewhat easier.

Rich used Autodesk Softimage (formerly XSI) to previsualise his movie. He built a virtual set, inserted some virtual characters and used the static models to represent people so he could see the camera angles which were be required for particular scenes, and he could see which scenes worked, which didn’t and how to change them. So in effect, each scene from the movie was extensively planned even before he picked up the camera. Each scene was modelled in XSI and the original XSI simple models were used when fleshing out the concept, but these were then further refined to give the final CG output for compositing.



Our movie-short is CGI heavy (as all our movies will be) so most scenes were filmed against a green screen in our studio. Green-screened movies usually require previs (unless the director is a genius) because there are no visual props or clues at all and thus there is no physical frame of reference. Because the actors are working in an empty room (which is horrendously difficult to do, especially when your actors are kids) it helps if the whole thing has been meticulously planned in advance, so that the cast and crew have printed artwork to look at before each scene and they know where to move and what to do, and also where to position the camera and which angles and lighting to use.

Even with groovy software like XSI, Rich still struggled in places. For example, the most complex scene in the movie was the bridge scene, which had nine virtual cameras and involved very complex choreography, all performed against a green-screen backdrop. The previs allowed Rich to experiment with different options and see how each change affected future scenes. He could work out the correct scene cuts and play around with different scenarios before deciding which scenes worked best. He could then finalise his choices and print a final storyboard, which was important not only for the actors (who could look at printed examples from the previs in order to visualise out what was happening) but also so that Rich could work out the photography as well as making sure that the crew never crossed the line (I’ll be blogging about “the line” at a later date.)

Previs is undoubtedly the future of filmmaking, particularly when complex CGI and special effects are used. Mercifully, with the advancement of technology, we no longer have to resort to Coppola’s tedious and complicated methods in order to visualise and plan our movies. Modern filmmaking software now makes scenic previsualisation available to the indie filmmaker, allowing him to explore his creative vision in a flexible virtual environment at minimal cost.

Alas, XSI doesn’t come with a hot-tub though. I guess we indie filmmakers can’t have everything…

Labels: DIAPP, previs