Creating Sunlight - DISTANTLIGHT command

Creates a distant light.

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Note: Starting with AutoCAD 2016-based products, all standard lights are calculated as photometric lights. It is recommended to update all standard lights in a scene to photometric lights. Photometric lighting is enabled by setting the LIGHTINGUNITS system variable to 1 or 2.

The following prompts are displayed.

Note: The options for this command vary slightly depending on the LIGHTINGUNITS setting.

Light Direction

Specifies the direction of the distant light with two points, a point to start from and a second point to go toward. The Vector option provides a method to specify the coordinates that represent the vector direction of the light. For example, the default value of the vector coordinates 0.0000,-0.0100,1.0000, points the light approximately in the positive Z-axis direction.

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.

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 is the perceived power emitted in all directions. Luminance is the total luminous flux incident on a surface, per unit area.

Note: The Photometry option is available only when the LIGHTINGUNITS system variable is set to 1 or 2.

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 asterick (*) 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.

Note: Starting with AutoCAD 2016-based products, shadows are always rendered no matter the current status or values of the Shadow option. This option is maintained for scripting and backwards compatibility.

Off

Turns off the 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.

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

Specifies the softness to use to calculate the shadow map.

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.