About Light Nodes
Lights are fairly simple nodes that are used to illuminate the database. Although there is only one light node, it supports ambient, spotlight, and infinite [parallel] light functionality.
Ambient
An ambient light casts rays in a spherical pattern. Any light with its Directional flag set to True and its Aperture set to 180 degrees is an ambient light. New lights are always ambient. You can right click on any light and set it to Ambient.
Figure 1.1. An ambient light.
Spot
A spotlight casts a cone of rays along a specific vector. The width of the cone is set by the Aperture flag. Directionality is controlled by the Direction X, Direction Y, and Direction Z parameters. You can right click on any light and set it to Spot.
Figure 1.2. A spotlight.
Figure 1.3. A spotlight.
Infinite [Also Called Parallel]
An infinite light casts parallel light rays along a specific vector. Any light with its Directional flag set to false is an infinite light source. Azimuth, which represents how high the "sun" is in the sky and therefore the angle of the light rays, is set by the Direction X, Direction Y, and Direction Z parameters. You can right click on any light and set it to Infinite. Infinite lights create the same lighting regardless of their Position parameters.
Figure 1.4. An infinite light.
Figure 1.5. An infinite light.
Area Of Effect
The area of effect for any light is limited by its position in the hierarchy. [Unless the light's Global parameter is set to True.] For example, the following lights effects only the nodes below them. It doesn't matter if the light is Ambient, Spot, or Infinite. A non-global light is limited by its position in the hierarchy.
- Scene
- AmbientLight
- Terrain1x1. Full lighting.
- Terrain1x2 Full lighting.
- Terrain2x1 Full lighting.
- Terrain2x2 Full lighting.
- Scene
- Terrain1x1. No lighting.
- Terrain1x2. No lighting.
- AmbientLight
- Terrain2x1. Full lighting.
- Terrain2x2. Full lighting.
- Scene
- TerrainGroup 1
- AmbientLight1
- Terrain1x1. Affected By AmbientLight1.
- Terrain1x2. Affected By AmbientLight1.
- TerrainGroup 2
- AmbientLight2
- Terrain2x1. Affected By AmbientLight2.
- Terrain2x2. Affected By AmbientLight2.
- TerrainGroup 1
- Scene
- TerrainGroup 1
- AmbientLight1
- Terrain1x1. Affected By AmbientLight1 and InfiniteLight.
- Terrain1x2. Affected By AmbientLight1 and InfiniteLight.
- TerrainGroup 2
- AmbientLight2
- Terrain2x1. Affected By AmbientLight2 and InfiniteLight.
- Terrain2x2. Affected By AmbientLight2 and InfiniteLight.
- TerrainGroup 1
- InfiniteLight [Global = True]
Light Bindings
Typically scenery is allowed an unlimited number of static lights but only a few dynamic lights. Eight and sixteen are typical limits. This is the first level of light management. You can set a light as dynamic by setting its Dynamic parameter to True. Keep in mind any limitations on dynamic lights. Once the scene reaches its limit for dynamic lights, all other lights should have their Dynamic parameter to False.
For performance reasons, some geometry is affected by the dynamic lights and some is not. These bindings are associated with meshes, not lights.
Registration
Class registration and implementation information is as follows:
| Category Type | Information |
| Implementation | C++ |
| Module | GEOMETRY.DLL |
| Core | Yes |
| Class Hierarchy | Node » Light |
| Outgoing Dependencies | None |