Pixar, renowned for their cutting edge animation, know better than anyone the advantages of saving time where possible. The technical directors and supervisors on Cars 2 were faced with the challenge of building locations for this feature length animation. Those of you who have seen the sequel will remember that the lead character, Lightning McQueen, is being sent around the globe to race in the world Grand Prix. The challenge for the Pixar creative team was to build recognizable cities, on a very broad scale.
Most of the cityscapes in Cars 2 needed to be fully 3D, particularily in the chase scenes where spy jets fly over the cities. The ad-hoc process used on previous films to create a cityscape through rendering and matte painting would have been too expensive for this production. So too were any conventional techniques where set dressers would hand-place buildings of various sizes in a set to give an appearance of something less predictable. There were simply too many locations and too much city to cover.
A city like London that has developed organically over time will challenge the most experienced designer. The team started to notice how roads were not on a grid and blocks were not a perfect square. To tackle this, a new strategy was considered, and so the team turned to CityEngine. CityEngine is a software package that allows you to efficiently translate conceptual designs into 3D cities and buildings. Professionals working in architecture, urban planning, GIS and general 3D content production all use this software. For this project, CityEngine was customised to meet the challenges of creating 3D representations of cities like London, Paris and Tokyo.
For London they started by building a collection of parts that could be recombined in different ways to look like a particular era of brick or stone building, while maintaining accurate representations of the buildings. The art department designed buildings that matched the style of London, such as store fronts, balconies, doors and windows. The set designers took these designs and fed them into CityEngine, assembling 37,000 buildings based on set rules. They then created a road network that would divide the buildings into blocks, while remaining true to the original facades. To their relief CityEngine was able to handle this information really well.
The work for Tokyo was very similar, as CityEngine was worked into the pipeline. They started with the background buildings in Tokyo, while also taking existing models of foreground buildings, chopping them into components and breaking the areas into city blocks. By setting rules, CityEngine could stack the components on various heights. They applied the finishing touches by shading with Slim in Autodesk’s Maya, and rendering was done using Pixar’s RenderMan, of which version 5 will be released soon.
It may not have been Pixar’s first choice, but CityEngine worked out to be a very useful and time saving tool on this production. It will be interesting to see how CityEngine goes on to assist other teams in the film industry.
To find out more about CityEngine, please use to the following link.