CEIG08
Permanent URI for this collection
Browse
Browsing CEIG08 by Subject "Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Estimación de Densidades usando GPUs(The Eurographics Association, 2008) Lastra, M.; Urena, C.; Bittner, J.; García, R.; Montes, R.; Luis Matey and Juan Carlos TorresEste artículo presenta un método de estimación de densidades basado en rayos que ha sido implementado completamente en la GPU. La estimación de densidades basada en rayos reduce el sesgo de los enfoques clásicos basados en fotones aunque tiene un costo computacional más alto. Proponemos algoritmos y estructuras de datos para la implementación en GPUs de la estimación de densidades basada en rayos y mostramos que la técnica propuesta da hasta un orden de magnitud de aceleración comparada con su variante CPU. La aceleración obtenida se incrementa al aumentar el número de rayos y por tanto el método es muy útil en aplicaciones que requieran renderización de alta calidad.Item NURBS-based Inverse Reflector Design(The Eurographics Association, 2008) Anson, Oscar; Seron, Francisco J.; Gutierrez, Diego; Luis Matey and Juan Carlos TorresCommonly used direct rendering techniques simulate light transport for a complete scene, specified in terms of light sources, geometry, materials, participating media, etc. On the other hand, inverse rendering problems take as input a desired light distribution and try to find the unknown parts of the scene needed to get such light field. The latter kind, where inverse reflector design is included, is traditionally solved by simulation optimization methods, due to the high complexity of the inverse problem. In this paper we present an inverse reflector design method which handles surfaces as NURBS and simulates accurately the light transport by means of a modified photon mapping algorithm. The proposed method is based on an optimization method, called pattern search, in order to compute the reflector needed to generate a target near light field. Some assumptions are determined in order to reduce the complexity of the problem, such as a rotationally symmetric reflector or its perfectly specular reflective behavior. The optimization method specifies the reflector shape by handling a NURBS curve as a generatrix, sequentially modifying the position and weights of its control points in order to obtain the reflector solution. Areas of applications of inverse reflector design span from architectural lighting design to car headlamps design