An artist friendly hair shading system

Abstract

Rendering hair in motion pictures is an important and challenging task. Despite much research on physically based hair rendering, it is currently difficult to benefit from this work because physically based shading models do not offer artist friendly controls. As a consequence much production work so far has used ad hoc shaders that are easier to control, but often lack the richness seen in real hair. We show that physically based shading models fail to provide intuitive artist controls and we introduce a novel approach for creating an art-directable hair shading model from existing physically based models. Through an informal user study we show that this system is easier to use compared to existing systems. Our shader has been integrated into the production pipeline at the Walt Disney Animation Studios and is being used in the production of the upcoming animated feature film Tangled.

User-Centered Design of Gpu-Based Shader Programs

“…One of the very few publications concerned with the design of user interfaces for shaders is the work by Sadeghi et al (Sadeghi et al, 2010), who identified three requirements for artist-friendly control parameters:…”

“…Based on these principles, we extended the three principles proposed by Sadeghi et al (Sadeghi et al, 2010) and include three additional principles. Thus, our six principles for the user-centered design of interfaces to control parameters of shaders are:…”

“…As discussed by Sadeghi et al (Sadeghi et al, 2010), it is sometimes useful to optionally couple parameters; for example, in order to allow users to find an initial solution by manipulating only a subset of all parameters and automatically computing further, coupled parameters. Novice users who are not familiar with all parameters would particularly benefit from such a coupling.…”

“…This work focuses on the user-centered design of interfaces for GPU-based vertex and pixel shaders in game engines and is, therefore, partly based on the principles for artist-friendly controls of Renderman shaders proposed by Sadeghi et al (Sadeghi et al, 2010), which are reviewed in Section 2. However, we also take the actual user interface (including the choice and design of widgets) into account.…”

3-D Simulation of Double-Bar Plush Fabrics with Jacquard Patterns

“…The methods for 3-D simulation of pile include the geometric modeling and texture generating. Csuri, [4] Neulander, [5] Sadeghi, [6] and Yan [7] drew the animal furs very clearly with the geometric method, but it was time-consuming and mostly used for offline rendering for film production and animation. Kajiya [8] plotted furs with three-dimensional texture generating method, and the plotted fur was very real and soft, but the early methods were not efficient in simulating knitting products.…”