Projected Light Source

The projected light source casts light from a single point forming a focused beam aimed in a specific direction. This type of light is visualized in a form of a pyramid. Due to its form, it is versatile and can be conveniently used to simulate the numerous light emitting sources: for example, car headlights, flash light, or street lamps.

Projected light sources can produce shadows of accurate perspective projection. They require only a single rendering pass and are performance-cheap if compared to the world and omni light sources.

As the projected light can have different shapes, it can be used to create area lights.

See Also#

To add a projected light, do the following:

1. On the Menu bar, click Create -> Light -> Projected

   

2. Place the light somewhere in the world.

   

Parameters of the projected light can be adjusted in the Node tab of the Parameters window. It includes both the common parameters and the parameters specific for the projected light source. The specific ones are described below.

Light Settings#

Field of view	A field of view of the projected light. This parameter defines the angle of the light clipping in range from 1 (only a very narrow segment is illuminated) to 175 degrees (the whole hemisphere is lit). Field of view = 20 Field of view = 65 Field of view = 90
Near clipping	The near clipping plane that truncates the light pyramid to necessary extend. This parameter adjusts the distance relative pyramid vertex for cutting off the top surface. The default 0.1 fits to represent a very small snip emitting the light. Near clipping = 0 Near clipping = 0.5
Mode	The type of texture used to define light's distribution: IES — light distibution is defined by the IES profile, a lighting industry standard of describing how the light is cast based on real-world measured light fixtures. Projected light sources without and with IES profile Simple — an arbitrary 2D texture is projected onto the scene. All the surfaces receiving the formed light pattern are redrawn in additional rendering pass, this is required because of manipulations with texture matrix. 1st texture projected 2nd texture projected
Texture	A simple or IES texture projected by the Projected light.
Relative to FOV	The IES texture rendering mode: Disabled — the unchanged IES texture is clipped by the light source's Field of View. Enabled — the IES texture is scaled to fit within the light source's Field of View.

Attenuation Settings#

Penumbra

A light penumbra is used to simulate edge gradual falloff. This parameter determines how fast the intensity decreases from the center of spot to the non-illuminated areas border. If the attenuation power is set to 0 or close to it, the edge between illuminated and non-illuminated areas will be sharp. Increasing the value up will render softly dispersed light at the non-illuminated areas border. Penumbra = 0 Penumbra power = 1 Penumbra power = 5