/ Karol Myszkowski / Associate Professor
/ Vladimir L. Volevich / Visiting Associate Professor
/ Roman Durikovic / Assistant Professor
/ Satoshi Nishimura / Assistant Professor
The laboratory is currently working on the following topics:
Refereed Journal Papers
In this paper, we present an efficient global illumination technique, and then we discuss the results of its extensive experimental validation. The technique is a hybrid of cluster-based hierarchical and progressive radiosity techniques, which does not require storing links between interacting surfaces and clusters. We tested our technique applying a multi-stage validation procedure which we designed specifically for global illumination solutions. At first, experimental validation of the algorithm against analytically-derived and measured real-world data is performed to check how calculation speed is traded for lighting simulation accuracy for various clustering and meshing scenarios. Then the algorithm performance and rendering quality is tested by a direct comparison of the virtual and real-world images of a complex environment.
A novel view-independent technique for progressive global illumination computations has been developed that uses prediction of visible differences to improve both efficiency and effectiveness of physically-sound lighting solutions. The technique is a mixture of stochastic (density estimation) and deterministic (adaptive mesh refinement) algorithms that are used in a sequence optimized to reduce the differences between the intermediate and final images as perceived by the human observer in the course of lighting computations. The quantitative measurements of visibility were obtained using the model of human vision captured in the Visible Differences Predictor (VDP) developed by Daly \cite{Daly93}. The VDP responses were used to support selection of the best component algorithms from a pool of global illumination solutions, and to enhance the selected algorithms for even better progressive refinement of the image quality. Also, the VDP was used to determine the optimal sequential order of component-algorithm execution, and to choose the points at which switch-over between algorithms should take place. As the VDP is computationally expensive, it was applied exclusively at the stage of design and tuning of the composite technique, and so perceptual considerations are embedded into the resulting solution, though no VDP calculations are performed during the lighting simulation.
In designing a processor, it is important to know how the number, the type and the latency of functional units (FUs) affect its performance. In this paper, we propose a method for estimating the best-case performance when a set of FUs and a computation graph are given. Using such method, we can investigate the influence on performance against different sets of FUs. We did two experiments on geometry calculation of polygon rendering; one is to see the influences due to the number and the type of FUs, and the other is to see the influences due to the latency of FUs.
The implementation of a hardware accelerator for ray tracing is presented in this paper. Ray tracing is an image synthesizing technique for 3D scenes, and ray-traced images are realistic comparing to images rendered with other algorithms. Our accelerator employs a space subdivision method with hierarchical grids for an efficient implementation of the ray-tracing algorithm. The accelerator is based on a very high-level pipelined architecture in order to perform high-speed processing. We use Field Programmable Gate Arrays (FPGAs) for the implementation because of its flexibility. This paper particularly focuses on how to partition the hardware into multiple FPGA chips under the constraints on I/O pins and configurable logic blocks.
Refereed Proceeding Papers
This paper describes a music editing system called the PMML Integrated Emacs-based Composing Environment (PIECE). The system provides both a textual-language view and piano-roll view synchronized with each other. The consistency between the views is maintained even if control structures or macros are used in the language texts. A novel algorithm for maintaining the consistency is presented.
Books
Technical Reports
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Academic Activities