4,937 research outputs found
An Integral geometry based method for fast form-factor computation
Monte Carlo techniques have been widely used in rendering algorithms for local integration. For example, to
compute the contribution of a patch to the luminance of another. In the present paper we propose an
algorithm based on Integral geometry where Monte Carlo is applied globally. We give some results of the
implementation to validate the proposition and we study the error of the technique, as well as its complexity.Postprint (published version
Rendering Curved Triangles on the GPU
This Thesis presents a new approach to render triangular BĂ©zier
patches in real time. The goal is to achieve a very good visual quality,
avoid artifacts in the silhouette, and get in nite detail.
Our approach consists in a ray casting technique to render tri-
angular B ezier patches in real time. It is based on previous work
explained in this document to implement a fast ray-surface intersec-
tion technique. This previous work consists in adapting Newton's
method to implement the intersections achieving interactive framer-
ates ray casting di erent surfaces.
The main contributions of our approach are adapting New-
ton's method to perform intersections with triangular bicubic B ezier
patches and implementing it in GPU to optimize performance using
graphics hardware.
Finally, we also contribute adapting the normal mapping tech-
nique to shade the models and, thus, achieve even greater detail
Using Patran and Supertab as pre- and postprocessors to COSMIC/NASTRAN
Patran and Supertab are interactive computer graphics pre- and postprocessors that can be used to generate NASTRAN bulk data decks and to visualize results from a NASTRAN analysis. Both of the programs are in use at the Numerical Structural Mechanics Branch of the David Taylor Research Center (DTRC). Various aspects of Patran and Supertab are discussed including: geometry modeling, finite element mesh generation, bulk data deck creation, results translation and visualization, and the user interface. Some advantages and disadvantages of both programs will be pointed out
Computationally efficient ray tracing of parametric surfaces
Includes bibliographical references (page 9).Abstract also in Japanese.Algorithms for ray tracing parametric surfaces are in general too computationally expensive to be widely applicable. The algorithm presented here combines well-known graphics procedures with a modified Newton iteration to provide a computationally efficient means of including parametric surfaces in a ray traced image. By allowing only planar surfaces to be reflective and/or refractive the resulting high degree of ray coherence is utilized to make the algorithm incremental and results in an order of magnitude improvement in computation speed over existing algorithms
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