Illuminate 3D renderersIn every Light you'll find theses same parameters (except Ambient Light): - one color by light passes : diffuse / specular / volumetric : see components of Surface and Volumetric Light to understand the matching parameters of theses emissions. - Attenuation is a curve representing the intensity of the light given the distance from it's emission point. Attenuation is in falloff by default but can by set to any Function. Note that the falloff is represented inside the viewport through the lights helpers.
Note that in the case of Directional Light and Projector Light (and more to come) if you go in advanced parameters mode, you'll have access to the Shadow parameters and scene bounding box which is the box in which shadows will be computed. In that section you can adjust the shadow map samples and narrow the area where shadow will be computed.
Last thing you must now about lights is that by default the got a whit map as input (which is easier to adjust their color and all) but in any light (again except Ambient Light) you can put anything as light map. Here I took an example from the Smode pack and put it under my projector Light.
PARAMETERS ON ALL LIGHTS
- Placement ( 3D Placement): Placement of the light
Area Light - Light defined by a plane
Ambient Light - Light coming from every directions
Directional Light - Orthographic light casting shadows
Point Light - Light emitted from a single point or sphere in all direction
Environment Light - Ambient illumination based on an environment map
Spot Light - Light emitted from a point in a direction using a radial range
Rectangular Light - Light emitted from a rectangle