Published papers

This paper describes modeling techniques of simple leaf blades of vegetal trees. The techniques are based on leaf morphology. A leaf blade is assumed to be symmetrical. A blade consists of the midrib, the blade surface, and veins. The general shape of a leaf blade is determined by the outline and the margin. Both outline and margin are defined by vectors. Main and secondary veins are 'pressed' onto the blade surface to create semi-cylindrical bumpiness on the blade surface. Displacement, bump, and texture mapping techniques are used to 'press' the venation pattern onto the blade surface, depending on the level of detail.

Artists do not always pursue photographic realism. The image abstraction and deformation of three-dimensional scenes are methods to communicate ideas. Images are the visual interpretation of real life or imaginary scenes. The author describes the idea of an infinite reflection model in which synthetic objects to be rendered are surrounded by closed reflective surfaces. The closed mirror surfaces create the 'feedback' effect which deforms objects inside the reflective space. This technique provides a new visual tool for artists and graphic designers.

Proposes new projection techniques of a three-dimensional object space on to a two-dimensional screen space. The techniques provide visual effects which break the laws of the traditional linear perspective technique. The curvilinear projection technique is shown to be a visual simulation of lens distortions. The inverse perspective projection technique is introduced which reverses the effects of perspective technique. The author further extends the new projection technique to achieve the trompe l'oeil effect using 3D warping techniques.

Presents a method of modeling atmospheric effects and rendering them using a volume tracing renderer. The model is built within a framework called the atmospheric cube. The atmospheric cube, or the A-cube, is a finite volume that encloses the three-dimensional scene to be modeled. The atmosphere is defined by particles of varying radii, which are distributed over the cube. The distribution of particles determines the density of atmosphere. The interaction of light with the atmosphere is divided into four cases to capture the characteristics of the atmospheric illumination by particles of different radii: absorption, Rayleigh scattering, Mie scattering, and geometric optics.

The paper presents a simple model for modeling and rendering of flames. The technique is based on a physical model of flame processes. This flame model accounts for both laminar and turbulent flames, with premixed and diffusion combustion. The basic geometry of flames relies on the laminar flame model. An anisotropic density field function is used to define the geometry of laminar flames. A stochastic function is added to perturb the basic geometry of flames to simulate the turbulent flames. Luminous flames from carbon particle scattering is added to the model by approximating the Mie scattering function.

Current three dimensional computer graphics assumes a vacuum space. The inclusion of atmosphere is essential for the modeling and rendering of natural phenomena. The paper presents an illumination model in the presence of atmosphere. The model is built within a framework called the atmospheric cube. The atmospheric cube, or the A-cube, is a finite volume that encloses the three dimensional scene to be modeled. The atmosphere is defined by particles of varying radii that are distributed over the cube.

The paper presents techniques to generate three-dimensional mosaic models. The techniques generate three-dimensional mosaics from two-dimensional bitmap images. The generated mosaic model data consist of three-dimensional 'units'. A 'unit' is a three-dimensional object which may be defined a a solid or surface. The lightness of each pixel controls the size of each 'unit', the luminance gradient in the image determines the rotational transformation of 'units'. The mosaic generation model is a powerful tool for artistic applications. Hue is used to control the shape of 'units'. The authors provide examples of art work using the mosaic model.