Digital Earth: TerraVision: VRML Sets


VRML Sets
•	Overview
•	Anchor/LOD Terrains
•	QuadLOD Terrains
•	Inline/LOD Terrains
•	Terrains with Site Models
•	Interactive Manipulation with the EAI
•	Composite Datasets

Digital Earth> Terravision^TM > VRML Sets > Anchor/LOD Terrains

Anchor/LOD Terrains

These datasets use our Anchor/LOD technique for managing deep level of detail hierarchies. For VRML performance reasons, we split deep LOD trees into a number of separate files containing only a small number of detail levels (e.g. 3 or 4 levels) . The user is able to click over any of the higher resolution tiles in a scene in order to zoom into that region. Using these techniques we are able to produce terrain datasets in the order of many gigabytes such that a standard VRML browser is able to view the data interactively.

	Yosemite Valley, CA A 21x27 km region inside Yosemite National Park, CA, at 1 m resolution imagery. The data include Yosemite Valley, featuring El Capitan and Half Dome. This dataset contains a total of 11 levels of detail, with a total dataset size of 1.9 GB. The imagery for this dataset is 21135 x 27090 pixels (JPEG compressed). Texture-mapped (4 LODs per scene) Flat-shaded (4 LODs per scene) Wireframe (4 LODs per scene)
	Denver, CO A 233x206 km region encompassing part of Colorado state, with 30 m resolution imagery. The city of Denver is toward the lower right corner of image. This dataset contains a total of 9 levels of detail, with a total dataset size of 73 MB. Elevations are exaggerated by a factor of 5. The imagery for this dataset is 6854 x 7755 pixels (JPEG compressed). Texture-mapped (4 LODs per scene) Flat-shaded (4 LODs per scene) Wireframe (4 LODs per scene)
	Camp Pendleton, CA A 59x70 km region around the Camp Pendleton site in Southern California with 30 m resolution imagery. This dataset contains a total of 8 levels of detail, with a total dataset size of 6 MB. Elevations are exaggerated by a factor of 5. The imagery for this dataset is 1992 x 2317 pixels (JPEG compressed). Texture-mapped (4 LODs per scene) Flat-shaded (4 LODs per scene) Wireframe (4 LODs per scene)
	Fort Irwin, CA. A 11x7 km region around Fort Irwin, with 1 m resolution imagery. This dataset contains a total of 12 levels of detail, with a total dataset size of 104 MB. The imagery for this dataset is 11362 x 6930 pixels (JPEG compressed). Texture-mapped (4 LODs per scene) Texture-mapped (3 LODs per scene) Flat-shaded Wireframe
	Fort Benning, GA A 3x2 km region around Fort Benning, with 15 cm resolution imagery. This dataset contains a total of 11 levels of detail, with a total dataset size of 166 MB. The imagery for this dataset is 18932 x 15533 pixels (JPEG compressed, grayscale). Texture-mapped (4 LODs per scene) Flat-shaded (4 LODs per scene) Wireframe (4 LODs per scene)
	LOD test dataset This dataset is based upon the Fort Irwin terrain above but instead of imagery-mapped terrain, each tile is just a single, flat, randomly colored polygon. This can be interesting to see how the hierarchical levels of detail switch with distance. Total dataset size = 58 MB. Test dataset (4 LODs per scene)