Overlay Management

CentralBodyGraphics allows efficient rendering and organization of terrain and imagery overlays. This includes out-of-core memory management for high resolution terrain and images, level of detail control, and hierarchal culling.

Technical Details: Globe overlay rendering is based on the 2002 paper Rendering Massive Terrains using Chunked Level of Detail Control.

Both terrain and imagery overlays can be added to the central body in a single call by using the AddUriString method as shown below.

[C#] Copy Code
IAgStkGraphicsTerrainOverlay overlay = scene.CentralBodies.Earth.Terrain.AddUriString(terrainOverlayPath);

A TerrainOverlay is created and added to the central body.

Alternatively, overlays can be created with initializers, and then added to the central body as shown below.

[C#] Copy Code
IAgStkGraphicsSceneManager manager = ((IAgScenario)root.CurrentScenario).SceneManager;
IAgStkGraphicsTerrainOverlay terrainOverlay = manager.Initializers.AGIProcessedTerrainOverlay.InitializeWithString(terrainOverlayPath);
scene.CentralBodies.Earth.Terrain.Add(terrainOverlay);

When an overlay should no longer be rendered, remove the overlay from the central body.

[C#] Copy Code
scene.CentralBodies.Earth.Terrain.Remove(overlay);

STK Engine for UNIX 11.2