Visualization of fluids has wide applications in science, engineering and entertainment. Various methodologies of visualizing fluids have evolved which emphasize on capturing different aspects of the fluids accurately. In this survey the existing methods for realistic visualization of fluids are reviewed. The approaches are classified based on the key concept they rely on for fluid modeling. This classification allows for easy selection of the method to be adopted for visualization given an application. It also enables identification of alternative techniques for fluid modeling.

In traditional animation, keyframes are modeled and standard graphics pipeline is used to animate the scene. In this paper we consider volume animation where the 3D world and its components are represented as a voxel model. The voxel model is annotated with hierarchical feature information and thus facilitates easy volume editing. These annotations are based on regularised Minkowski operators used in constructing/sculpting the model. The Selective editing of volume models also becomes possible with these annotations. The pure voxel or volumetric approach used from start to finish has the advantage that extremely simple data structures and algorithms enable us to generate complex volume animations.

A new Extensible Markup Language (XML) application, Molecular Dynamics Language (MoDL) has been developed. MoDL provides a simple, but powerful tool for molecular dynamics visualization and has been developed by combining, for the first time, the strengths of XML and the Virtual Reality Modeling Language. The details of MoDL, its implementation and examples of its use are presented in this paper.

Any modeling scheme for gaseous phenomena in graphics has to capture three aspects: the fuzzy geometry of the gas, the dynamics, characterized by the presence of vortices, and the interaction of light with the gaseous volume. We represent the gaseous volume as a particle system and apply Vortex Element Methods (VEM) to model the dynamics. A Lagrangian formulation that is gridless and hence ideal for unbounded flows is used. A gridless approach to ray tracing the particle systems is developed using particle maps. These maps are used to estimate densities within a gaseous volume analogous to the way volume photon maps are used to estimate radiance during Monte Carlo ray tracing. A technique is proposed to merge particle and volume photon maps to obtain an effective method for simulating multiple scattering in a dynamic inhomogeneous participating medium. Our method for modeling and rendering gaseous phenomena is conceptually simple and grid free. Particle maps play an effective role, as the nearest neighbor information obtained during the rendering phase is exploited during the dynamics computation. We preset results that demonstrate the effectiveness of our approach. Copyright © 2000 John Wiley & Sons, Ltd.

Interactive sculpting is the process by which a designer can impose free form shape changes on the object being designed. It has potential applications in fields like computer aided geometric design and rapid prototyping. Our approach to interactive sculpting is through the intermediate step of interactive virtual machining (IVM). IVM is a subset of interactive sculpting in that the degrees of freedom available to the sculptor are reduced. The goal of our work is to demonstrate the feasibility of interactive virtual machining on a shared memory multiprocessor workstation. Our prototype IVM system uses a voxel based approach. It provides common machining tools to the user and uses Minkowski operations (P.K. Ghosh, 1993) to implement those tools. Parallel implementation of the virtual machining tools has shown that sculpting with 256/sup 3/ voxel array is possible with frame rate of around 20 frames/sec. We present the parallel algorithms for virtual machining tools and the results of implementation on a shared memory multiprocessor environment.

B-Splines, in general, and Non-Uniform Rational B-Splines (NURBS), in particular, have become indispensable modeling primitives in computer graphics and geometric modeling applications. In this paper, a novel high-performance architecture for the computation of uniform, nonuniform, rational, and nonrational B-Spline curves and surfaces is presented. This architecture has been derived through a sequence of steps. First, a systolic architecture for the computation of the basis function values, the basis function evaluation array (the BFEA), is developed. Using the BFEA as its core, an architecture for the computation of NURBS curves is constructed. This architecture is then extended to compute NURBS surfaces. Finally, this architecture is augmented to compute the surface normals, so that the output from this architecture can be directly used for rendering the NURBS surface.