Spot lights emit a directional cone of light. The direction and size of the cone of light can be controlled by setting the light’s target location and hotspot and falloff angles.
The intensity of a spot light diminishes over distance, based on its attenuation properties. If attenuation is turned off, the intensity does not diminish over distance.
The following code shows how to setup a basic spot light:
// To setup a spot light AcDbLight spotLight; spotLight.setLightType(AcGiDrawable::kSpotLight); spotLight.setPosition(AcGePoint3d(0,0,5)); spotLight.setHotspotAndFalloff(40,150); spotLight.setTargetLocation(AcGePoint3d(0,0,0));