CPS616 -- Terrain On Demand

The following satellite image show a 89km x 89km area of new York state. All this area is available to vistualize through VRML. Currently, the area is divied into 7x7 grid. When the user select a point of interest in the image, the entire grid element, which contains the location, is shown. This limitation only exists for this user interface. A java user interface can allow user to select a area of interest.

After a point of interest is selected, the user is asked to decided on the block size of the subgrid. The subgrid is used to exploy the LOD node's view volumn culling and multiple resolution representation. As a result, the user's browser can provide the best presentation of the data.

The polygons within each element of the subgrid is optimized. The edges of the grid are extracted at the highest resolution to ensure the continuity between grid elements. As a result, a large grid element allows better polygon optimization. However, since large grid element size implies less LOD nodes, the browser has limited option on the presentation.