RYAN: Rendering Your Animation Nonlinearly projected

Artistic rendering is an important research area in Computer Graphics, yet relatively little attention has been paid to the projective properties of computer generated scenes. Motivated by the surreal storyboard of an animation in production---Ryan---this paper describes interactive techniques to control and render scenes using nonlinear projections. The paper makes three contributions. First, we present a novel approach that distorts scene geometry such that when viewed through a standard linear perspective camera, the scene appears nonlinearly projected. Second, we describe a framework for the interactive authoring of nonlinear projections defined as a combination of scene constraints and a number of linear perspective cameras. Finally, we address the impact of nonlinear projection on rendering and explore various illumination effects. These techniques, implemented in Maya and used in the production of the animation Ryan, demonstrate how geometric and rendering effects resulting from nonlinear projections can be seamlessly introduced into current production pipelines