Continuous Level of Detail for Large Scale Rendering of 3D Animated Polygonal Models

2012 ◽  
pp. 194-203
Author(s):  
Francisco Ramos ◽  
Oscar Ripolles ◽  
Miguel Chover
Keyword(s):  
Large Scale ◽  
Level Of Detail ◽  
Polygonal Models

scholarly journals Evaluating Rockfall Risk: Some Critical Aspects

Geosciences ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 98 ◽  
Author(s):  
Claudio Scavia ◽  
Monica Barbero ◽  
Marta Castelli ◽  
Maddalena Marchelli ◽  
Daniele Peila ◽  
...  
Keyword(s):  
Large Scale ◽  
Risk Estimation ◽  
Risk Process ◽  
Level Of Detail ◽  
Risk Level ◽  
Multi Scale ◽  
Mountain Environments ◽  
Open Questions ◽  
Hazard And Risk ◽  
Historical Heritage

Rockfalls evolve rapidly and unpredictably in mountain environments and can cause considerable losses to human societies, structures, economical activities, and also natural and historical heritage. Rockfall risk analyses are complex and multi-scale processes involving several disciplines and techniques. This complexity is due to the main features of rockfall phenomena, which are extremely variable over space and time. Today, a considerable number of methods exists for protecting land, as well as assessing and managing the risk level. These methodologies are often very different from each other, depending on the data required, the purposes of the analysis, and the reference scale adopted, i.e., the analysis level of detail. Nevertheless, several questions still remain open with reference to each phase of the hazard and risk process. This paper is devoted to a general overview of existing risk estimation methodologies and a critical analysis of some open questions with the aim of highlighting possible further research topics. A typical risk assessment framework is exemplified by analyzing a real case study. Each step of the process is treated at both the detailed and the large scale in order to highlight the main characteristics of each level of detail.

scholarly journals BRLO-Tree: A Data Structure Used for 3D GIS Dynamic Scene Rendering

2015 ◽  
Vol 15 (4) ◽  
pp. 124-137 ◽  
Author(s):  
Wenju Wang ◽  
Zhang Xuan ◽  
Liujie Sun ◽  
Zhongmin Jiang ◽  
Jingjing Shang
Keyword(s):  
Data Structure ◽  
Large Scale ◽  
Three Dimensional ◽  
Level Of Detail ◽  
Dynamic Scene ◽  
3D Gis ◽  
Dynamic Scenes ◽  
Complex Dynamic ◽  
3D Objects ◽  
System A

Abstract BRLO-Tree (Block-R-Tree-Loose-Octree) is presented in this paper based on the R-Tree and Loose-Octree. The aim of the structure is to visualize the large scale and complex dynamic scenes in a 3D (three-dimensional) GIS (Geographic Information System). A new method of clustering rectangles to construct R-tree based on an improved K-means algorithm is put forward. Landform in 3D GIS is organized by R-Tree. The block is used as the basic rendering unit. The 3D objects of each block are respectively organized by a Loose-Octree. A series of techniques, based on this data structure, such as LOD (Level of Detail), relief impostors are integrated. The results of the tests show that BRLO-Tree cannot only support the large scale 3D GIS scene exhibition with wandering and fighting, but it can also efficiently manage the models in a dynamic scene. At the same time, a set of integrated techniques based on BRLO-Tree can make the rendering pictures more fluence and the rendering time vastly improved.

A hybrid level-of-detail representation for large-scale urban scenes rendering

2014 ◽  
Vol 25 (3-4) ◽  
pp. 243-253 ◽  
Author(s):  
Shengchuan Zhou ◽  
Innfarn Yoo ◽  
Bedrich Benes ◽  
Ge Chen
Keyword(s):  
Large Scale ◽  
Level Of Detail ◽  
Urban Scenes ◽  
Detail Representation

scholarly journals LARGE-SCALE CARTOGRAPHIC REPRESENTATION OF RELIEF FEATURES FROM SANDYZATION PROCESS

2020 ◽  
Vol 26 (4) ◽  
Author(s):  
Bibiana Salvador Cabral da Costa ◽  
Claudia Robbi Sluter ◽  
Andrea Lopes Iescheck ◽  
Éder Luís da Silva Rodrigues
Keyword(s):  
Large Scale ◽  
Level Of Detail ◽  
Topographic Maps ◽  
Surface Model ◽  
Digital Surface Model ◽  
Concentrated Flow ◽  
Contour Lines ◽  
Remotely Piloted Aircraft ◽  
Data Survey ◽  
Geomorphological Features

Abstract: In topographic maps, contour lines and elevation points usually represent the variation of height and slope. Contour lines interval defines the level of detail for relief representation. Geomorphological features we can identify on maps are related to contour lines generalization. In this study, we aim to define the necessary level of detail for the cartographic representation of relief features from the sandyzation process. The methodology comprises: defining the relief features associated with sandyzation at the study area by literature review; describing the aspects of data survey using Remotely Piloted Aircraft (RPA) to generate the orthophoto mosaic and the Digital Surface Model (DSM); and using the DSM to extract contour lines at different scales. We defined eight relief features (denudational landform, rill, ravine, micro-residual hill, dune, depositional fan, concentrated flow, and gully) for contour cartographic representation at 1:5,000, 1:1,000, 1:500, 1:200, and 1:100 scales. The results show the scales in which the relief features have their geomorphological characteristics better represented by contours lines. Since there is no reference for suitable scales for the cartographic representation of landforms related to the sandyzation process, this study can contribute to geomorphological researches in areas where this process occurs.

scholarly journals 3D Simplification Methods and Large Scale Terrain Tiling

2020 ◽  
Vol 12 (3) ◽  
pp. 437
Author(s):  
Ricard Campos ◽  
Josep Quintana ◽  
Rafael Garcia ◽  
Thierry Schmitt ◽  
George Spoelstra ◽  
...  
Keyword(s):  
Large Scale ◽  
State Of The Art ◽  
Level Of Detail ◽  
Web Based ◽  
European Area ◽  
Levels Of Detail ◽  
Triangulated Irregular Networks ◽  
Large Scale Dataset ◽  
Irregular Networks ◽  
Elevation Data

This paper tackles the problem of generating world-scale multi-resolution triangulated irregular networks optimized for web-based visualization. Starting with a large-scale high-resolution regularly gridded terrain, we create a pyramid of triangulated irregular networks representing distinct levels of detail, where each level of detail is composed of small tiles of a fixed size. The main contribution of this paper is to redefine three different state-of-the-art 3D simplification methods to efficiently work at the tile level, thus rendering the process highly parallelizable. These modifications focus on the restriction of maintaining the vertices on the border edges of a tile that is coincident with its neighbors, at the same level of detail. We define these restrictions on the three different types of simplification algorithms (greedy insertion, edge-collapse simplification, and point set simplification); each of which imposes different assumptions on the input data. We implement at least one representative method of each type and compare both qualitatively and quantitatively on a large-scale dataset covering the European area at a resolution of 1/16 of an arc minute in the context of the European Marine Observations Data network (EMODnet) Bathymetry project. The results show that, although the simplification method designed for elevation data attains the best results in terms of mean error with respect to the original terrain, the other, more generic state-of-the-art 3D simplification techniques create a comparable error while providing different complexities for the triangle meshes.

A New Construction Method for Web-Based Large-Scale 3D Terrain Model

2012 ◽  
Vol 204-208 ◽  
pp. 4922-4927
Author(s):  
Zhen Pei Li ◽  
Ze Gen Wang ◽  
Hong Liang Jia
Keyword(s):  
Large Scale ◽  
Level Of Detail ◽  
Network System ◽  
Network Environment ◽  
Web Based ◽  
Terrain Model ◽  
3D Terrain ◽  
New Construction ◽  
Data Source ◽  
Display Performance

With the development of network and information technology, it is highly desirable to create 3D geoscience applications in the network environment. However, construction of web-based 3D terrain model is one of the foundation works of 3D geoscience applications in the network environment. This paper presents a new method of constructing large-scale 3D terrain model based on Extensible 3D (X3D). In this way, we first use Geospatial components of X3D to build 3D terrain model by using DEM as the data source, then we publish the 3D terrain model to the internet with a architecture of Brower/Server and plug-in technology. To promote the display performance of large-scale 3D terrain model, We presents an approach that using the Level of Detail (LOD) technology to simplify the 3D terrain model. The application results show that the method this paper presented has advantage of easy to integrate with other network system, thereby easy to realize data sharing and interoperation; the method also has virtues of fast display speed, high ability of interaction. It’s an effective method for constructing large-scale 3D terrain model in network environment.

scholarly journals A New Simplification Algorithm for Colored or Textured Polygonal Models

2000 ◽  
Vol 4 (4) ◽  
pp. 1-20 ◽  
Author(s):  
Kun Zhou ◽  
Mingmin Zhang ◽  
Jiaoying Shi ◽  
Zhigeng Pan
Keyword(s):  
Measuring Method ◽  
Mesh Simplification ◽  
Level Of Detail ◽  
Continuous Transition ◽  
Polygonal Mesh ◽  
Adaptive Subdivision ◽  
Lod Models ◽  
Textured Models ◽  
Polygonal Models ◽  
Vertex Clustering

Many applications in computer graphics require complex and highly detailed models. However, the level of detail actually necessary may vary considerably. It is often desirable to use approximations in place of excessively detailed models to control processing time. A new polygonal mesh simplification algorithm is presented for colored or textured models based on vertex clustering, and a more accurate error-measuring method for vertex clustering is introduced. The algorithm can produce high quality approximations of polygonal models. It makes adaptive subdivision of the bounding box in the original model using octree structure and performs vertex clustering in an error range specified by users. The color or texture information defined over the mesh can be preserved during simplification by constructing a texture map for the simplified mesh. To make a continuous transition between level of detail (LoD) models possible, an efficient interpolating method is also proposed. The efficiency of the algorithm is demonstrated in the experimental results.

Level of Detail and Multi-Resolution Modeling Techniques for Virtual Design and Prototyping

1999 ◽  
Author(s):  
Zhigeng Pan ◽  
Kun Zhou ◽  
Chiyi Cheng ◽  
Mingmin Zhang
Keyword(s):  
Virtual Reality ◽  
Large Scale ◽  
Level Of Detail ◽  
Data Sets ◽  
Virtual Design ◽  
Variable Resolution ◽  
Modeling Techniques ◽  
Resolution Model ◽  
Cad Models ◽  
Representation Scheme

Abstract Reconciling scene realism with interactivity has emerged as one of the most important areas in making virtual reality feasible for large-scale CAD data sets consisting of several millions of primitives. Level of detail (LoD) and multi-resolution modeling techniques in virtual reality can be used to speedup the process of virtual design and virtual prototyping. In this paper we present an automatic LoD generation and rendering algorithm which is suitable for CAD models and propose a new multi-resolution representation scheme called MRM (multi-resolution model), which can support efficient extraction of fixed resolution and variable resolution for multiple objects in the same scene. MRM scheme supports unified selective simplifications and selective refinements over the mesh. Furthermore, LoD and multi-resolution models may be used to support real-time geometric transmission in collaborative virtual design and prototyping.

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