Source Location

Specify the source location by entering coordinate values or using the pointing device.

Name

Specifies the name of the light. You can use uppercase and lowercase letters, numbers,
spaces, hyphens (-), and underscores (_) in the name. The maximum length is 256 characters.

Intensity/Intensity Factor

Sets the intensity or brightness of the light. The range is 0.00 to the maximum value
that is supported by your system.

Hotspot

Specifies the angle that defines the brightest cone of light, which is known to lighting
designers as the beam angle. This value can range from 0 to 160 degrees or the equivalent
values based on AUNITS.

Falloff

Specifies the angle that defines the full cone of light, which is also known as the
field angle. This value can range from 0 to 160 degrees. The default is 50 degrees
or the equivalent values based on AUNITS. The falloff angle must be greater than or
equal to the hotspot angle.

Status

Turns the light on and off. If lighting is not enabled in the drawing, this setting
has no effect.

Photometry

Photometry is the measurement of the luminous intensities of visible light sources.

In photometry, luminous intensity is a measure of the perceived power emitted by a
light source in a particular direction. Luminous flux is the perceived power per unit
of solid angle. The total luminous flux for a lamp is the perceived power emitted
in all directions. Luminance is the total luminous flux incident on a surface, per
unit area.

Intensity

Enter an intensity value in candelas, the perceived power in a luminous flux value,
or illuminance value for the total luminous flux incident on a surface.

• Candela (symbol: cd) is the SI unit of luminous intensity (perceived power emitted
  by a light source in a particular direction). Cd/Sr
• Lux (symbol: lx) is the SI unit of illuminance. Lm/m^2
• Foot-candle (symbol: fc) is the American unit of illuminance. Lm/ft^2

Enter f to specify the perceived power in a luminous flux value.

If you enter i, you can specify the intensity of the light based on an illuminance value.

The illuminance value can be specified in either lux or foot-candles. Enter d to specify a distance to use to calculate illuminance.

Color

Specify the color of the light based on a color name or a Kelvin temperature. Enter
? to display a list of color names.

Enter a text string using wild card characters to display a partial listing of color
names, or an asterisk (*) to display all the possible choices.

If you enter k, you can specify the color of the light based on a Kelvin temperature value.

Shadow

Makes the light cast shadows.

Off

Turns off display and calculation of shadows for the light. Turning shadows off increases
performance.

Sharp

Displays shadows with sharp edges. Use this option to increase performance.

Soft Mapped

Displays realistic shadows with soft edges.

Map Size

Specifies the amount of memory that should be used to calculate the shadow map.

Softness

Specifies the softness that should be used to calculate the shadow map.

Soft Sampled

Displays realistic shadows with softer shadows (penumbra) based on extended light
sources.

Specify the shape of the shadow by entering s and then the dimensions of the shape. (For example, the radius of the sphere or the
length and width of a rectangle.)

Specify the sample size by entering a.

Specify the visibility of the shape by for the shadow by entering v.

Attenuation

Attenuation Type

Controls how light diminishes over distance. The farther away an object is from a
spotlight, the darker the object appears. Attenuation is also known as decay.

NOTE:When the LIGHTINGUNITS system variable is set to 1 or 2, the Attenuation option has
no affect on the light when rendered. This option is maintained for scripting and
backwards compatibility.

• None. Sets no attenuation. Objects far from the spotlight are as bright as objects close
  to the light.
• Inverse Linear. Sets attenuation to be the inverse of the linear distance from the light. For example,
  at a distance of 2 units, light is half as strong as at the spotlight; at a distance
  of 4 units, light is one quarter as strong. The default value for inverse linear is
  half the maximum intensity.
• Inverse Squared. Sets attenuation to be the inverse of the square of the distance from the light.
  For example, at a distance of 2 units, light is one quarter as strong as at the spotlight;
  at a distance of 4 units, light is one sixteenth as strong.

Use Limits

Specifies whether to use limits or not.

Attenuation Start Limit

Specifies the point where light starts as an offset from the center of the light.
The default is 0.

Attenuation End Limit

Specifies the point where light ends as an offset from the center of the light. No
light is cast beyond this point. Setting an end limit increases performance where
the effect of lighting is so minimal that the calculations are wasted processing time.

Color/Filter Color

Controls the color of the light.

True Color

Specifies a True Color. Enter in the format R,G,B (red, green, blue).

Index

Specifies an ACI (AutoCAD Color Index) color.

HSL

Specifies an HSL (hue, saturation, luminance) color.

Color Book

Specifies a color from a color book.