X3D Example Archives: VRML 2 Sourcebook, Chapter 25 Level Of Detail

Level of detail (LOD) allows an overall world become very large by letting an author provide high-fidelity models when a viewer is nearby, and simpler geometry when the viewer is far away.

The further the viewer can see, the more there is to draw. Note that if a shape is distant, the shape is smaller and the viewer can't see as much detail. So... draw it with less detail. Varying detail with distance reduces initial download time and increases drawing speed.

Increase performance by making multiple levels of shapes: high detail for close up viewing, progressively lower detail for more distant viewing. Group the levels in an LOD node, ordered from high detail to low detail, and using an array of range values to select switching distances .

These X3D scenes are adapted directly from the original VRML 2.0 Sourcebook chapter examples. Also available: VRML 2.0 Sourcebook course notes.

Figure 25.04 Three Torches Side By Side

Figure 25.12 Dungeon Rooms With Sliding Doors

  12 X3D Models       X3D Model Descriptions
   Figure25_01TorchHighDetail Figure25_01TorchHighDetail A high-detail torch.
   Figure25_02TorchMediumDetail Figure25_02TorchMediumDetail A medium-detail torch.
   Figure25_03TorchLowDetail Figure25_03TorchLowDetail A low-detail torch.
   Figure25_04ThreeTorchesSideBySide Figure25_04ThreeTorchesSideBySide The three torches side by side.
   Figure25_05ThreeTorchesSingleLOD Figure25_05ThreeTorchesSingleLOD Three torches within an LOD node. First you must change viewpoints or fly in to watch levels shift. Ordinarily transitions are hard to discern, these transitions are designed to be noticeable.
   Figure25_06DungeonRoomFloor Figure25_06DungeonRoomFloor A dungeon-room floor.
   Figure25_07DungeonRoomWall Figure25_07DungeonRoomWall A dungeon-room wall.
   Figure25_08DungeonRoom Figure25_08DungeonRoom A dungeon room.
   Figure25_09TwoDungeonRoomsWithLODHiding Figure25_09TwoDungeonRoomsWithLODHiding Two dungeon rooms controlled by LOD nodes, move forward to see second room.
   Figure25_10DungeonWallWithDoorway Figure25_10DungeonWallWithDoorway A dungeon wall with a doorway, created using Coordinate and TextureCoordinate.
   Figure25_11DungeonDoor Figure25_11DungeonDoor A dungeon door.
   Figure25_12DungeonRoomsWithSlidingDoors Figure25_12DungeonRoomsWithSlidingDoors Two dungeon rooms controlled by LOD nodes and separated by a wall and a pair of sliding doors.

The X3D Resources: Examples page and X3D Developers Guide provide more information about the production of this archive.