Art Directed Watercolor Shader for Non-photorealistic Rendering with a Focus on Reflections
Abstract
In this research, I demonstrated that emulating painterly reflections is impossible using
existing modeling, compositing and rendering software that does not provide programming
capabilities. To obtain painterly reflections, we need to emulate three aspects of
painterly reflections: (1) shape of reflections; (2) glossiness of reflections; and (3) colors
of reflections. The first two turn out to be relatively easy. However, despite the perceived
simplicity of color reproduction, the third one turned out to be hardest without developing
our own proprietary tools.
To demonstrate the difficulty, I have developed a shader using commercial rendering
and shading software that does not provide explicit programming power. I assigned my
shader as a surface material to 3D objects. Using my shader, I was able to create computer
generated watercolor style renderings without reflections. My shader provide rendering
effects such as diffuse, contours, specularity, shadow, and reflections. Although I can
faithfully emulate non-reflected regions of given water-color paintings, I demonstrate that
my shader cannot produce reflection colors that are faithful to colors of original reflections.
Citation
Cheng, Ji (2017). Art Directed Watercolor Shader for Non-photorealistic Rendering with a Focus on Reflections. Master's thesis, Texas A & M University. Available electronically from https : / /hdl .handle .net /1969 .1 /165773.