Despite the current ubiquity of realistic computer-generated imagery, it is important to keep in mind the demand for editing capability. In Japanese animation, the use of hand-drawn images has long offered full artistic control. Regardless, storytelling purposes in the sense of dynamic, detailed scenes, but also budget and time constraints, are increasingly leading artists towards 3D content creation. Nevertheless, designers want to retain the traditional anime style.
One of the most crucial aspects of the toon look is cel shading. It is typically implemented by remapping the Lambertian reflectance to a ramp, replacing the smooth, realistic gradient by several blocks of quantized colors. Yet beyond this basic functionality, designers often have an array of feature requests that vastly differs per production. To satisfy the artists' needs, we present a new tool for Maya implemented as a set of custom Arnold shaders.
This project was implemented in C++ using the Autodesk Maya API, for the Arnold, Maya Software and Maya Hardware renderers.