The development of wireless telecommunication requires higher speed data rates. Wideband MIMO systems are a possible answer to that need. Both wideband and MIMO characteristics enhance multipath propagation, and require a precise knowledge of the channel to properly exploit their capabilities. The extraction of the channel parameters can be done from the measurements, but also from simulations....

Abstract The ray series method may be generalized using a ray centered coordinate system for general 3D-heterogeneous media. This method is useful for Amplitude Versus Offset (AVO) seismic modeling, seismic analysis, interpretational purposes, and comparison with seismic field observations.For each central ray (constant ray parameter), the kinematic (the eikonal) and dynamic ray tracing system ...

Ray tracing, which computes radiance, is traditionally regarded as an off-line rendering algorithm that is too slow for interactive use. In this paper, we present an interactive system that uses 4D interpolants to approximate radiance, while providing guaranteed error bounds. Our system exploits the object-space, ray-space, image-space and temporal coherence in radiance to accelerate ray tracin...

In this paper, we present a mapping of nonlinear ray tracing to the GPU which avoids any data transfer back to main memory. The rendering process consists of the following parts: ray setup according to the camera parameters, ray integration, ray–object intersection, and local illumination. Bent rays are approximated by polygonal lines that are represented by textures. Ray integration is based o...

To further increase the realism of ray tracing, we take the idea of distributed ray tracing and add on to it mirage rendering. Mirages are seen quite often in our daily lives, and in order to make computer generated images look as realistic as possible, it is necessary to add things, such as mirage rendering, that are seen in the natural world. Mirages are caused by light passing from colder ai...

Height field ray tracing is one approach to photorealistic visualization of terrain. Parametric methods, which fall into a new class of height field ray trace methods, are introduced 1. The height field is horizontally sliced into evenly spaced cross-sections. For each cross-section, the Euclidean distance from each point to the nearest point where the slice cuts through terrain is computed off...

We present a novel technique for ray tracing geometry represented by points. Our approach makes it possible to render high quality ray traced images with global illumination using unstructured point–sampled data thus avoiding the time-consuming process of reconstructing the underlying surface or any topological information. Compared with previous point rendering methods, our approach allows for...

We propose a simple yet eeective extension of ray-tracing algorithm that allows selective visibility of objects for speciic rays. Typically, rays are clas-siied as pixel, shadow, reeected and transmitted. We suggest adding a visibility mask to material descriptions , which controls how these rays interact with the material. This addition can be incorporated seamlessly into any ray-tracer and ma...

We present the necessary theory for the integration of subdivision surfaces into general purpose rendering systems. The most important functionality that has to be provided via an abstract geometry interface are the computation of surface points and normals as well as the ray intersection test. We demonstrate how to derive the corresponding formulas and how to construct tight bounding volumes f...