Non-Photorealistic Computer Graphics Library

IMPaSTo - A Realistic, Interactive Model for Paint

Author(s): William Baxter, Jeremy Wendt, Ming C. Lin.
Proceedings: 3rd International Symposium on Non-Photorealistic Animation and Rendering (NPAR'04), pp. 45--56, June, 2004.
[BibTeX]

Abstract:
We present a paint model for use in interactive painting systems that captures a wide range of styles similar to oils or acrylics. The model includes both a numerical simulation to recreate the physical flow of paint and an optical model to mimic the paint appearance. Our physical model for paint is based on a conservative advection scheme that simulates the basic dynamics of paint, augmented with heuristics that model the remaining key properties needed for painting. We allow one active wet layer, and an unlimited number of dry layers, with each layer being represented as a height-field. We represent paintings in terms of paint pigments rather than RGB colors, allowing us to relight paintings under any fullspectrum illuminant. We also incorporate an interactive implementation of the Kubelka-Munk diffuse reflectance model, and use a novel eight-component color space for greater color accuracy. We have integrated our paint model into a prototype painting system, with both our physical simulation and rendering algorithms running as fragment programs on the graphics hardware. The system demonstrates the model’s effectiveness in rendering a variety of painting styles from semi-transparent glazes, to scumbling, to thick impasto.