Depending on the editor from which you set these options, you may see a subset or all of the following attributes:
Click the arrow to choose a light type from the drop-down list. When you change a light’s type, only those attributes common to both types retain their previous values or settings. Values and settings for non-common attributes are lost. When you change a light’s light type, the light’s position is also preserved.
Set the color of the light. Click the swatch either to change the light’s color in the Color Chooser or to map a texture to the light. If you map a texture, the light projects it (depending on the light Type). The default setting is white. The following shows the rendered result when you map a Ramp texture to an Ambient light’s Color attribute.
Represents the brightness of the light. A light with an Intensity value of 0 produces no light. A light with a negative Intensity value removes light from a scene in the area of the light’s influence. The slider range is 0 to 10, but you can type in a larger value for a brighter light (for example, 20). The default value is 1.
If on, the light illuminates all objects and is included in the defaultLightSet. If off, the light only illuminates objects to which it is linked. Illuminates by Default is on by default.
Emit Diffuse and Emit Specular are on by default. Turning them off turns off the diffuse or specular shading results for the light.
The results do not show in the scene view. To see the results, test render in Render View.
To enable or disable the diffuse and specular shading for multiple lights at the same time, use the Rendering Flags window (Windows > Rendering Editors > Rendering Flags).
This determines the volumetric shape of the light. Select a light shape from the drop-down list: Box, Sphere, Cylinder, or Cone. Sphere is the default.
If on, the light produces depth map shadows (for directional, point, or spot lights) or raytraced shadows (for ambient lights). Cast Shadows is off by default. See also Shadow attributes.
The color of shadows produced by the light. Use a colored shadow to simulate shadows produced by transparent, colored surfaces (for example, colored glass). The default setting is black.
You can also map textures to shadows to create interesting effects. The following example shows a Checker texture mapped to the Shadow Color of a Spot Light.
If you decide to map a texture that has color (such as the Stucco texture in the following example), change the texture’s color to black and white if desired.
The colorRange is the color of the light from the center to the edge of the volume. By changing the values on the ramp (gradient) you can decay or change color along the defined light direction. The right side of the ramp represents the light color at the center of the volume. The left side is the color at the outer boundary. The effect of decay is accomplished by the interpolation (blend) from the inner color to the outer color. The outermost color should be black to avoid a hard boundary at the volume edge.
See Set attributes using ramps for more information on how to customize your ramp by adding additional color entries.
Advanced ramp features exist. For more information, see Ramp Shader.
Position of the active color entry in the ramp.
The color of the active color entry.
Controls the way colors blend in the ramp. Select an option from the drop-down list: None, Linear, Smooth, Spline. The default is Linear.
The direction of the light within the volume. Select an option from the drop-down list: Outward, Inward, Down Axis. The default is Outward.
Emit Specular has no effect on Inward lights.
Use this option to create a partial sphere, cone, or cylinder light shape by specifying a degree of rotation. Values can range from 0 to 360 degrees. The most common settings are 180 and 360, the default. 180 is similar to slicing the light volume in half and 360 is the full light. This option does not apply to the box light shape.
This option applies to the cone light shape only. This is the relative size of one end of the cone. At a value of 1.0 it is a cylinder, while at 0 it is a cone.
If turned on, light affects surfaces in a multi-directional manner. The default is off.
When combined with Emit Diffuse, the lighting of a surface is 50% of the surface/light angle, and 50% in a non-directional fashion. If Emit Diffuse is off then the light is totally omnidirectional.
If Emit Diffuse and Emit Specular are off and Emit Ambient is on, the light behaves like an ambient light with decay and a bounded range. This is quite useful for adjusting lighting. It can be used with negative light intensity to pull light out of defined regions.
This section applies to cone and cylinder light shapes only. This contains attributes for managing the penumbra, the area of partial illumination around the shadow border and the light. Using the graph you can adjust the spread and the dropoff of the light. The left side of the graph represents the intensity at the outer edge of the cone or cylinder and the right side represents the intensity from the center of the beam to the edge.
This value affects the active entry in the graph and is represented on the x-axis of the graph.
This value affects the active entry in the graph and is represented on the y-axis of the graph.
This controls the way the values are calculated. Select an option from the drop-down list: None, Linear, Smooth, Spline. The default is Linear.