Non-photorealistic rendering using watercolor inspired textures and illumination

The authors present a watercolor inspired method for the rendering of surfaces. Our approach mimics the watercolor process by building up an illuminated scene through the compositing of several layers of semitransparent paint. The key steps consist of creating textures for each layer using LIC (Line Integral Convolution) of Perlin Noise (K. Perlin, 1985), and then calculating the layer thickness distribution using an inverted subtractive lighting model. The resulting watercolor-style images have color coherence that results from the mixing of a limited palette of paints. The new lighting model helps to better convey large shape changes, while texture orientations give hints of less dominant features. The rendered images therefore possess perceptual clues to more effectively communicate shape and texture information