Visualization of large terrains made easy

We present an elegant and simple to implement framework for performing out-of-core visualization and view-dependent refinement of large terrain surfaces. Contrary to the trend of increasingly elaborate algorithms for large-scale terrain visualization, our algorithms and data structures have been designed with the primary goal of simplicity and efficiency of implementation. Our approach to managing large terrain data also departs from more conventional strategies based on data tiling. Rather than emphasizing how to segment and efficiently bring data in and out of memory, we focus on the manner in which the data is laid out to achieve good memory coherency for data accesses made in a top-down (coarse-to-fine) refinement of the terrain. We present and compare the results of using several different data indexing schemes, and propose a simple to compute index that yields substantial improvements in locality and speed over more commonly used data layouts. Our second contribution is a new and simple, yet easy to generalize method for view-dependent refinement. Similar to several published methods in this area, we use longest edge bisection in a top-down traversal of the mesh hierarchy to produce a continuous surface with subdivision connectivity. In tandem with the refinement, we perform view frustum culling and triangle stripping. These three components are done together in a single pass over the mesh. We show how this framework supports virtually any error metric, while still being highly memory and compute efficient.

[1]  Jeffrey Scott Vitter,et al.  External memory algorithms and data structures: dealing with massive data , 2001, CSUR.

[2]  Mark A. Duchaineau,et al.  ROAMing terrain: Real-time Optimally Adapting Meshes , 1997, Proceedings. Visualization '97 (Cat. No. 97CB36155).

[3]  Martin Reddy,et al.  TerraVision II: Visualizing Massive Terrain Databases in VRML , 1999, IEEE Computer Graphics and Applications.

[4]  Renato Pajarola Large scale terrain visualization using the restricted quadtree triangulation , 1998 .

[5]  Hugues Hoppe Smooth view-dependent level-of-detail control and its application to terrain rendering , 1998 .

[6]  Jyh-Jong Tsay,et al.  External-memory computational geometry , 1993, Proceedings of 1993 IEEE 34th Annual Foundations of Computer Science.

[7]  Mike Bailey,et al.  Visualization of height field data with physical models and texture photomapping , 1997 .

[8]  William Ribarsky,et al.  Real-time, continuous level of detail rendering of height fields , 1996, SIGGRAPH.

[9]  William Ribarsky,et al.  An Integrated Global GIS and Visual Simulation System , 1997 .

[10]  V. Pascucci,et al.  Parallel accelerated isocontouring for out-of-core visualization , 1999, Proceedings 1999 IEEE Parallel Visualization and Graphics Symposium (Cat. No.99EX381).

[11]  John Rohlf,et al.  IRIS performer: a high performance multiprocessing toolkit for real-time 3D graphics , 1994, SIGGRAPH.

[12]  William Ribarsky,et al.  Intent, perception, and out-of-core visualization applied to terrain , 1998 .

[13]  Steven Skiena,et al.  Optimizing triangle strips for fast rendering , 1996, Proceedings of Seventh Annual IEEE Visualization '96.

[14]  Hugues Hoppe,et al.  View-dependent refinement of progressive meshes , 1997, SIGGRAPH.

[15]  Valerio Pascucci,et al.  Global static indexing for real-time exploration of very large regular grids , 2001, SC.

[16]  Hans-Peter Seidel,et al.  Real-time generation of continuous levels of detail for height fields , 1998 .

[17]  Peter Bro Miltersen,et al.  On showing lower bounds for external-memory computational geometry problems , 1998, External Memory Algorithms.

[18]  Luiz Velho,et al.  Variable Resolution 4‐k Meshes: Concepts and Applications , 2000, Comput. Graph. Forum.

[19]  Cláudio T. Silva,et al.  I/O optimal isosurface extraction (extended abstract) , 1997, VIS '97.

[20]  M. Gross,et al.  Fast multiresolution surface meshing , 1995, Proceedings Visualization '95.

[21]  Renato Pajarola Large scale terrain visualization using the restricted quadtree triangulation , 1998 .

[22]  Marc Levoy,et al.  QSplat: a multiresolution point rendering system for large meshes , 2000, SIGGRAPH.

[23]  David G. Kirkpatrick,et al.  Right-Triangulated Irregular Networks , 2001, Algorithmica.

[24]  Craig Gotsman,et al.  Visualization of large terrains in resource-limited computing environments , 1997 .

[25]  J. Dollner,et al.  Texturing techniques for terrain visualization , 2000, Proceedings Visualization 2000. VIS 2000 (Cat. No.00CH37145).

[26]  Yi-Jen Chiang,et al.  I/O optimal isosurface extraction , 1997, Proceedings. Visualization '97 (Cat. No. 97CB36155).

[27]  Jeffrey Scott Vitter,et al.  Efficient bundle sorting , 2000, SODA '00.