Adding Terrain Objects and Layers
Terrain objects and layers can be added to a PhotoMesh project to enable you to visualize how the model will appear in TerraExplorer’s 3D World.
You can add any of the following objects and layers:
§ Imagery and Elevation Layers
§ Terrain Objects (Modify Terrain and Hole on Terrain)
Locations
A location defines the geographical coordinates of a point on the terrain as well as the position from which the point is to be viewed.
To create a new location in the current camera position:
§ On the Tools tab, in the Objects and Layers group, click Create Location. The location of interest is set to the terrain coordinate at the center of the 3D Window. If there is no terrain at the center of the view (the camera is facing the sky), the location of interest is set to a distance of two times the current altitude of the camera above the terrain. The location is added to the Objects and Layers list.
Note: When you create a location, the point of interest is set only to the terrain coordinate of the center of the 3D Window and is not affected by any 2D or 3D models in front of the terrain.
3D Mesh Layers
3D Mesh Layers (3DML) can be loaded from 3DML files on your own computer or local network or from a database that is served over a network by SkylineGlobe 3D Mesh service.
To load a mesh layer:
1. On the Tools tab in the Objects and Layers group, click 3DML. The Browse for 3DML Layer dialog is displayed.
2. Browse to the required file, and click Open or select the required server type, and click Select. Then enter the information required for the selected server. See "Working with SkylineGlobe Server" in the “Basic Concepts” chapter for information.
3. After the layer has been placed on the terrain, you can change its properties using the property sheet. See "3D Mesh Layer Parameters" in the TerraExplorer User Guide for further information.
Imagery and Elevation Layers
Raster layers can be added to your project from either of the following:
§ Files on your own computer or on your local network.
§ A database that is served over a network by one of these GIS servers:
§ Web Map Service
§ Web Map Tile Service
§ Oracle Spatial Database
§ ECW Image Web Server
§ TerraGate Server
§ SkylineGlobe Server (See "Working with SkylineGlobe Server" in the “Basic Concepts” chapter for information.)
§ ArcSDE Raster Server
See the TerraExplorer User Guide for more information on loading raster layers.
To add an imagery/elevation source to a project:
1. On the Tools tab, in the Objects and Layers group, click Imagery Layer/Elevation Layer. The Load Imagery/Elevation Layer dialog is displayed.
2. Browse to the required file and select it, or select the server type and enter the required information.
3. Click Open.
Note: If the source file is geo-referenced, it is located accordingly on the terrain. Otherwise, it is placed at the center of the 3D Window. You can then manually edit its position, or reproject it.
4. After the layer has been placed on the terrain, you can change its properties using the property sheet.
Terrain Objects
The following terrain objects can be added to a PhotoMesh project to enable you to visualize how the model will appear in TerraExplorer’s 3D World:
Modifying the Terrain
Using the Modify Terrain tool, you can modify the elevation values in an area of the terrain by drawing a polygon in the 3D Window and then setting the Modify Terrain object’s properties in its property sheet. The surface of the terrain is raised or lowered according to the elevation values of the polygon's points. Different elevation behaviors allow replacing, cropping above or cropping below the original values of the terrain. The interior of the polygon can be flat or irregular in shape.
To modify the terrain:
1. On the Tools tab, in the Objects and Layers group, click Modify Terrain. The Modify Terrain property sheet is displayed.
2. With the cursor in the 3D Window, click to add the first point of the polygon.
3. Click again to add additional points of the polygon until you have marked the entire shape. You must place at least three points to define the polygon.
Note: When creating a Modify Terrain object, the lines of the polygon should not overlap each other.
Note: It is recommended to keep the number of polygon points to the minimum required to define the shape. Adding unnecessary points may adversely affect performance.
4. Right-click to finish the object.
5. Continue to edit the object’s parameters and shape, or close the property sheet to finish the operation. See "Modify Terrain Property Sheet" in the TerraExplorer User Guide for further information.
Cutting a Hole on Terrain
Cutting a hole on the terrain removes the terrain texture while maintaining the original contours of the terrain. The objects or feature layers created on the terrain in the area of the hole are drawn on the original contours of the terrain.
To cut a hole on the terrain:
1. On the Tools tab, in the Objects and Layers group, click Hole on Terrain. The Hole on Terrain property sheet is displayed.
2. With the cursor in the 3D Window, click to add the first point of the hole.
3. Click again to add additional points of hole until you have marked the entire shape.
4. Right-click to finish the hole.
Note: It is recommended to keep the number of hole points to the minimum required to define the shape. Adding unnecessary points may adversely affect performance.
5. Continue to edit the hole or close the property sheet to finish the operation. See "Hole on Terrain Property Sheet" in the TerraExplorer User Guide for further information.