An Extended Non-Photorealistic Rendering Technique for Depicting Motions of Multiple 3D Objects

In order to enrich visual communications, we present a non-photorealistic rendering technique that depicts motion of 3D objects in a still image. To realize this technique, ¿speed line¿, one of the most familiar techniques in Japanese cartoon ¿manga¿, is introduced. Our technique firstly decomposes a combined motion of 3D objects into a translational motion of the center of gravity of the object and its rotational motion. Then, to depict motion of the 3D object, we render texture-mapped polygons that generated from a series of geometrical positions of the 3D object that represent its animation progress with the 3D objects. Textures mapped to the polygons are changed automatically according to the speed of the 3D object. Experimental results verify that our technique is effective enough to automatically depict various motions of 3D objects in real time.