Real-Time Rendering of Strokes Using Multiple Illuminated Paper Textures

Abstract

In this paper, we generate a realistic drawing stroke that is highly affected by paper irregularity as one of the interactive NPR techniques. We focus on the similarity between textures appearing on illuminated paper surfaces and textures those are made by pigments depositing on paper surface by a drawing stroke. First, we capture 12 paper textures with shading from a paper surface. The paper surfece is illuminated from 12 directions by turning the paper surface each 30 degrees and photographed. These textures are corrected and defined as a Height Field. Next, a stroke is generated by the control points that is input by a pressure-sensitive tablet. By using paper textures along to the drawing direction and using Height Field values along to the pen pressures, we can simulate pigment depositions like charcoals, pastels, and crayons in real-time.