Large-scale terrain rendering using strip masks of terrain blocks

2008 ◽  
Author(s):  
Xingquan Cai ◽  
Jinhong Li ◽  
Zhitong Su
Keyword(s):  
Large Scale ◽  
Terrain Rendering

scholarly journals Prevention of Mountain Disasters and Maintenance of Residential Area through Real-Time Terrain Rendering

2021 ◽  
Vol 13 (5) ◽  
pp. 2950
Author(s):  
Su-Kyung Sung ◽  
Eun-Seok Lee ◽  
Byeong-Seok Shin
Keyword(s):  
Real Time ◽  
Graphics Processing Units ◽  
High Speed ◽  
Large Scale ◽  
Civil Engineering ◽  
Three Dimensional ◽  
Sampled Data ◽  
Residential Areas ◽  
Terrain Rendering ◽  
Mountain Disasters

Climate change increases the frequency of localized heavy rains and typhoons. As a result, mountain disasters, such as landslides and earthworks, continue to occur, causing damage to roads and residential areas downstream. Moreover, large-scale civil engineering works, including dam construction, cause rapid changes in the terrain, which harm the stability of residential areas. Disasters, such as landslides and earthenware, occur extensively, and there are limitations in the field of investigation; thus, there are many studies being conducted to model terrain geometrically and to observe changes in terrain according to external factors. However, conventional topography methods are expressed in a way that can only be interpreted by people with specialized knowledge. Therefore, there is a lack of consideration for three-dimensional visualization that helps non-experts understand. We need a way to express changes in terrain in real time and to make it intuitive for non-experts to understand. In conventional height-based terrain modeling and simulation, there is a problem in which some of the sampled data are irregularly distorted and do not show the exact terrain shape. The proposed method utilizes a hierarchical vertex cohesion map to correct inaccurately modeled terrain caused by uniform height sampling, and to compensate for geometric errors using Hausdorff distances, while not considering only the elevation difference of the terrain. The mesh reconstruction, which triangulates the three-vertex placed at each location and makes it the smallest unit of 3D model data, can be done at high speed on graphics processing units (GPUs). Our experiments confirm that it is possible to express changes in terrain accurately and quickly compared with existing methods. These functions can improve the sustainability of residential spaces by predicting the damage caused by mountainous disasters or civil engineering works around the city and make it easy for non-experts to understand.

scholarly journals A Method of Optimizing Terrain Rendering Using Digital Terrain Analysis

2021 ◽  
Vol 10 (10) ◽  
pp. 666
Author(s):  
Lei Zhang ◽  
Ping Wang ◽  
Chengyi Huang ◽  
Bo Ai ◽  
Wenjun Feng
Keyword(s):  
Large Scale ◽  
Frame Rate ◽  
Terrain Analysis ◽  
Image Pyramid ◽  
Digital Terrain Analysis ◽  
Terrain Rendering ◽  
Digital Terrain ◽  
Elevation Data ◽  
View Frustum Culling ◽  
Elevation Model

Terrain rendering is an important issue in Geographic Information Systems and other fields. During large-scale, real-time terrain rendering, complex terrain structure and an increasing amount of data decrease the smoothness of terrain rendering. Existing rendering methods rarely use the features of terrain to optimize terrain rendering. This paper presents a method to increase rendering performance through precomputing roughness and self-occlusion information making use of GIS-based Digital Terrain Analysis. Our method is based on GPU tessellation. We use quadtrees to manage patches and take surface roughness in Digital Terrain Analysis as a factor of Levels of Detail (LOD) selection. Before rendering, we first regularly partition the terrain scene into view cells. Then, for each cell, we calculate its potential visible patch set (PVPS) using a visibility analysis algorithm. After that, A PVPS Image Pyramid is built, and each LOD level has its corresponding PVPS. The PVPS Image Pyramid is stored on a disk and is read into RAM before rendering. Based on the PVPS Image Pyramid and the viewpoint’s position, invisible terrain areas that are not culled through view frustum culling can be dynamically culled. We use Digital Elevation Model (DEM) elevation data of a square area in Henan Province to verify the effectiveness of this method. The experiments show that this method can increase the frame rate compared with other methods, especially for lower camera flight heights.

Research on Optimization and Application of LOD Algorithm in Virtual Reality Visualization of Terrain

2014 ◽  
Vol 687-691 ◽  
pp. 1258-1261
Author(s):  
Jing Sun ◽  
Hong Tao Wang
Keyword(s):  
Virtual Reality ◽  
Real Time ◽  
Large Scale ◽  
Design Work ◽  
Terrain Rendering ◽  
Key Technology ◽  
Progressive Mesh ◽  
Key Technologies ◽  
Methods And Techniques ◽  
Visibility Culling

With the development of computer graphics, real-time rendering-based VF: technology has been applied in more and more fields. LOD is the key technology in large-scale terrain rendering. In this paper, the basic concept of LOD is introduced briefly and some algorithms of LOD in use are mentioned and analyzed; secondly as one of algorithms of LOD, View-Dependent Progressive Mesh algorithm is studied and improved, the result of implementing the large-scale terrain’s LOD by using VDPM is presented. There are key technologies in LOD Large-scale terrain real-time rendering are researched. Relative technologies are presented such as: LOD of the terrain, visibility culling, and cracks eliminate, view-dependent refine, LOD error, technologies of texture etc. Using LOD technology, VR system can greatly reduce the; number of polygons produced in real-time rendering procedure. Finally, we do experimental design work based on the methods and techniques presented by this paper.

Large-Scale LOD Adaptive Terrain Rendering

2012 ◽  
Vol 220-223 ◽  
pp. 2450-2453 ◽  
Author(s):  
Wen Long Yu ◽  
Li Min Zhang ◽  
Bing Qiang Zhang
Keyword(s):  
Visual Acuity ◽  
Visual Perception ◽  
Large Scale ◽  
Dynamic Error ◽  
Smooth Transition ◽  
Evaluation Function ◽  
Static Error ◽  
Terrain Rendering ◽  
Quad Tree ◽  
Screen Space

The data structure is the form of quad-tree in this paper. The terrain node's LOD evaluation function is given through comprehensive considering the three factors which are the static error of the terrain block ,the screen space dynamic error and visual perception based on the premise of visual acuity. The smooth transition factor is used to eliminate the phenomenon of popping in the GPU vertex shader. The idea to join the skirts is used to eliminate cracks between terrain blocks. The experimental results show that the algorithm can reflect the terrain LOD levels through the fluctuant of terrain and the visual perception intensity so that the terrain has a better adaptability while increasing frame rates and rendering realistic.

scholarly journals Seamless Rendering of Large Scale Terrain

2012 ◽  
Vol 6-7 ◽  
pp. 1026-1030 ◽  
Author(s):  
Bao Song Deng ◽  
Tie Qing Deng ◽  
Rong Huan Yu ◽  
Jia Wei Yu
Keyword(s):  
Data Exchange ◽  
Large Scale ◽  
Computer Graphic ◽  
Open Data ◽  
Research Topic ◽  
Dependent Data ◽  
Huge Amount ◽  
Terrain Rendering ◽  
Data Control ◽  
Active Research

Terrain rendering has long been an active research topic in computer graphic and virtual reality. If large and detailed, digital terrains can be represented by a huge amount of data and therefore of graphical primitives to render in real-time. A dynamic, realistic and seamless rendering scheme for large scale terrain was proposed in this paper, based on successive LOD tiles and GPU acceleration. Multi-resolution girds and images were used for view-dependent data control and grid simplification, and multi-thread mechanism was employed for visibility clipping and data exchange between memory and disk, at the same time, a seamless combination algorithm between tiles of terrain and texture was proposed. Experimental results of real scenes with open data and comparisons with traditional method demonstrate the efficiency and practicality of our method.

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