Level-of-Detail Rendering of Large-Scale Irregular Volume Datasets Using Particles

This paper describes a level-of-detail rendering technique for large-scale irregular volume datasets.It is well known that the memory bandwidth consumed by visibility sorting becomes the limiting factor when carrying out volume rendering of such datasets.To develop a sorting-free volume rendering technique,we previously proposed a particle-based technique that generates opaque and emissive particles using a density function constant within an irregular volume cell and projects the particles onto an image plane with sub-pixels.When the density function changes significantly in an irregular volume cell,the cell boundary may become prominent,which can cause blocky noise.When the number of the sub-pixels increases,the required frame buffer tends to be large.To solve this problem,this work proposes a new particle-based volume rendering which generates particles using metropolis sampling and renders the particles using the ensemble average. To confirm the effectiveness of this method,we applied our proposed technique to several irregular volume datasets,with the result that the ensemble average outperforms the sub-pixel average in computational complexity and memory usage. In addition,the ensemble average technique allowed us to implement a level of detail in the interactive rendering of a 71-million-cell hexahedral volume dataset and a 26-million-cell quadratic tetrahedral volume dataset.

Flexible visualization framework for head-mounted display with gesture interaction interface

As the development of new visualization systems,within the field of simulation,offers their users more insights from their simulations,immersive systems are becoming a part of the visualization techniques.With the recent advancements of the Head-Mounted Displays(HMDs)and popularity of motion sensors,human beings and computer become more interactive.This study aims to evaluate the potential of such systems as a visualization tool through the development of a new flexible framework for visualization within virtual reality(VR)environment,using an Oculus Rift and a Leap Motion.Two approaches are then compared:high-3D object rendering within the virtual scene approach and a user experience-oriented system with an intuitive interface.To assess the quality of the interface and its relevance for the user,different types of gestures are implemented and tested.From an experiment on users to evaluate the developed system as a proper visualization tool,the HMDs,paired with a motion sensor to make a gesture-controlled interface seem to be promising mediums despite various constraints on development regarding the technology limitations.

A visualization for the dynamic behaviors of the mixture of water mass for northwestern pacific near Japan

(1)This article,published on 20 June 2013,had the following title:A VASUALIZATION FOR THE DYNAMIC BEHAVIORS OF THE MIXTURE OF WATER MASS FOR NORTHWESTERN PACIFIC NEAR JAPAN Here“VASUALIZATION”should be“VISUALIZATION”.

A VASUALIZATION FOR THE DYNAMIC BEHAVIORS OF THE MIXTURE OF WATER MASS FOR NORTHWESTERN PACIFIC NEAR JAPAN

Recent studies are focusing on the distribution of water mass because the mixture region of water mass is highly related to the rich fishing grounds[Yasuda I.,Watanabe Y.,Fish.Oceanogr.3(3):172–181,1994].Due to the large data size and time-varying property,efficient exploration and visualization of the ocean data is always extremely challenging.To extract the dynamic behaviors of the water mass and its mixture from a large-scale simulated ocean dataset,we developed an efficient visualization system by applying our volume compression method and our volume rendering method.This system allows us to investigate the time-varying distributions of ocean physical properties,additionally from the user’s perspective and requirements.In the experiments,we show the generality and expressiveness by applying our system for single-and multi-property visualizations to find some significant ocean water mass.Consequently,we could obtain a clear visualization result to show the dynamic behaviors of the mixture of water mass for simulation data regarding a location in the northwestern Pacific near Japan.