This report outlines the design and implementation of an algorithm to sweep a 3 dimensional tetrahedral complex in a particular direction. The problem is considered in its most generality, that is, the tetrahedral complex can be concave and have holes inside it which can themselves be concave. This algorithm can be used to e ciently perform ray-tracing of 3-D objects. The main idea in the algor...

3D ray tracing produces accurate, deterministic channel models for wireless system design. Increasing a ray tracing algorithm's ability to identify correct propagation paths reduces the kinematic errors of a simulation. This paper presents a new 3D ray tracing technique that reduces kinematic errors associated with ray launching algorithms. This work is sponsored by the NSF Presidential Faculty...

This paper is a continuation of our previous work [1] on the elaboration of first principles model for computing the BSDF (Bi-directional Scattering Distribution Function) of a cloth. New method realizes the idea of full statistical approach to cloth modeling with probabilistic goniometrical spectrophotometer. The main goal of the paper is to determine (based on original cloth model) parameters...

Ray tracing [Appe68] [Gold71] is widely acknowledged as a rendering approach that can produce very realistic and beautiful images [Whit80]. It is also widely known that ray tracing is very expensive computationally. Many intersection culling algorithms have been proposed to reduce this expense. However, such intersection culling algorithms do not take into consideration the nature of the primit...

Tracing garbage collection (GC) identifies dead objects by scanning the object-graph from the root set references. It is proven to be highly efficient and widely used in commercial managed runtime systems for Java, C# and scripting languages. However, tracing GC cannot identify the dead objects before finishing object-graph traversal. Hence the application cannot reuse the space of the dead obj...

We model weak gravitational lensing of light by large-scale structure using ray tracing through N-body simulations. The method is described with particular attention paid to numerical convergence. We investigate some of the key approximations in the multi-plane ray tracing algorithm. Our simulated shear and convergence maps are used to explore how well standard assumptions about weak lensing ho...

In this paper, a ray-tracing technique to predict the propagation channel parameters in indoor scenarios is presented. It is a deterministic technique, fully three-dimensional, based on geometrical optics (GO) and the uniform theory of diffraction (UTD). A model of plane facets is used for the geometrical description of the environment. The ray tracing is accelerated considerably by using the A...

INTRODUCTION This paper contributes to the modeling and auralization of diffraction which is one of the most important acoustic phenomenon caused by the wave nature of sound. However, most room acoustic modeling algorithms rely on geometrical acoustic techniques which completely neglect the diffraction. The reason for this is that such methods as ray-tracing [1], beam-tracing [2] and image-sour...

Even on the latest workstations ray tracing is still a very time-consuming algorithm. This paper makes a thorough analysis of previous attempts to accelerate ray tracing by means of parallelization with general purpose processors and by means of designing special purpose processors. Since much work has been done concurrently by many researchers, only the most important milestones are mentioned....

different patterns of pressure systems together with local factors, leads in generation, risingand spread of dust in west of iran. in this study, to investigate the factors causing the occurrence of dust inkermanshah province, 132 cases of dust phenomena (code: 06) were selected and analyzed using kermanshahsynoptic station data for the spring and summer seasons in a period of 5 years (2005-200...