Trans-Polygon Stroke Method for Frame Coherent Pastel Images

Abstract

We propose Trans-Polygon Stroke Method (TPSM) for creating pastel-like animation that keeps frame-to-frame coherence. There are several variable factors in hand-drawn pastel such as paper roughness and pigments. When these factors are simulated in computer graphics animation, they cause flickers, which reduces visibility. To increase the visibility of pastel-like animation by reducing the flickers, it is need to fix the factors. The procedure of the TPSM is to (1) model objects with quadrilateral polygons, (2) generate particles on the polygons, (3) give a vector direction to each particle, and (4) draw a line from the particle to the n-th polygon along with the direction. Besides the TPSM, the amount of pigments used for one stroke is read from a given table to fix this variable factor. We demonstrate several types of drawn strokes, such as hatching, stipple, and blending, using the proposed method.