Koji Nakamaru and Yoshio Ohno
Ohno Lab, Graduate School of Computer Science, Faculty of Science and Technology, Keio University
3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522
The Curves primitive defined in RenderMan is useful for modelling and rendering ribbonlike objects. This paper gives a simple framework for ray-curve intersection tests in ray tracing, and provides concrete details for one form of the primitive. The form is especially important for fine objects such as hair and fur.