Distantlight

Works with Bricscad (Windows) Pro and Platinum

Creates a distant light.

Accessing the Command

command bar:  distantlight

menu bar: View | Rendering | Lights | New distant light

toolbar: Lights |

 

: commandline

Prompts you in the command bar:

Specify light direction from <0,0,0> or [Vector]: (Type V then press Enter to choose Vector, specify a point or press Enter to accept the light direction from 0,0,0.)

Specify vector direction <0.0000,-0.0100,1.0000>: (Type the vector direction at the command prompt and press Enter to confirm.)

Specify light direction TO <1,1,1>: (Specify a point or press Enter to accept point 1,1,1)

 

If the LIGHTINGUNITS system variable is 0 (No lighting units), the following prompt displays:

Enter an option to change: Name/Intensity/Status/shadoW/Color/<eXit>: (Enter an option or press Enter to exit.)

 

If the LIGHTINGUNITS system variable is 1 (American lighting units) or 2 (International lighting units), the following prompt displays:

Enter an option to change: Name/Intensity factor/Status/Photometry/shadoW/filterColor/<eXit>: (Enter an option or press Enter to exit.)

Command Options

Option

Description

Name

Enter light name <Distantlight1>: (Enter a name or press Enter to accept the default name.)

Intensity Factor

Intensity

Enter intensity (0.00 - max float) <1.0>: (Enter the intensity. Values between 0.00 and the maximum value supported by your system are accepted.)

Status

Enter status OFf/<ON>: (Choose ON to include the light when calculating a rendering.)

Photometry

Enter a photometric option to change: Color/eXit/<Intensity>:

  • Enter intensity (Cd) or enter an option [Flux/Illuminance] <1500.0>: (Enter the intensity expressed in Candela (Cd).)

    • Enter Flux (Lm) : (Enter the luminous flux expressed in Lumen (Lm).)

    • Enter Illuminance (Lx or Fc) or enter an option [Distance] <9424.8>: (Enter the illuminance expressed in Lux (Lx) or Foot-candle (Fc).)

      • Enter Distance <1.0>: (Enter a distance expressed in drawing units.)

  • Enter color name or enter an option [?/Kelvin] <D65>:

    • Enter color name(s) to list <*>: (Enter a color name from the list. Type * to see the list)

      • D65

      • Fluorescent

      • Coolwhite

      • Whitefluorescent

      • daylightfluorescenT

      • Incandescent

      • Xenon

      • Halogen

      • Quartz

      • Metalhalide

      • mErcury

      • Phosphormercury

      • highpressureSodium

      • Lowpressuresodium

    • Enter Kelvin temperature <3600.0>: (Enter a color temperature expressed in degrees Kelvin (K).)

Candela: The candela (symbol: cd) is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function (a standardized model of the sensitivity of the human eye to different wavelengths, also known as the luminous efficiency function). A common candle emits light with a luminous intensity of roughly one candela.

Lumen: The lumen (symbol: Lm) is the SI unit of luminous flux, a measure of the power of light perceived by the human eye. Luminous flux differs from radiant flux in that luminous flux measurements (such as lumens) are intended to reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements (such as watts) indicate the total power of light emitted. The lumen is defined in relation to the candela as: 1 lm = 1 cd·sr

As a full sphere has a solid angle of 4·pi steradians, a light source that uniformly radiates one candela in all directions has a total luminous flux of 1 cd·4pi sr = 4pi ≈ 12.57 lumens. For example, if a candle emits light with a luminous intensity of about 1 candela, the total light emitted is about 12.6 lumens.

Illuminance: In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception.

If LIGHTINGUNITS=2 (International lighting units):
In SI derived units illuminance is measured in lux (lx) or lumens per square metre.

If LIGHTINGUNITS=1 (American lighting units):
The foot-candle (Fc) is a non-metric unit of illuminance that is used in photography. The unit is defined as the amount of illumination the inside surface of a 1-foot radius sphere would be receiving if there were a uniform point source of one candela in the exact center of the sphere. Alternatively, it can be defined as the illuminance on a 1-square foot surface of which there is a uniformly distributed flux of one lumen. This can be thought of as the amount of light that actually falls on a given surface. The foot-candle is equal to one lumen per square foot. One foot-candle is equal to approximately 10.764 lux, although in the lighting industry, typically this is approximated as 1 foot-candle being equal to 10 lux.

Kelvin temperature: Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that light source. The temperature is conventionally stated in units of absolute temperature: degrees kelvin (K).

Higher color temperatures (5,000 K or more) are called cool colors (blueish white); lower color temperatures (2,700–3,000 K) are called warm colors (yellowish white through red).

 

Shadow

Enter shadow settings [Off/Sharp/soFt mapped/soft sAmpled] <Sharp>: (Enter a shadow setting.)

  • Off: Disables the calculation of shadows for the light.

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

  • Soft mapped: Displays realistic shadows with soft edges.

    • Enter map size [64/128/256/512/1024/2048/4096] <256>:

  • Soft sampled:

    • Enter an option to change Shape/sAmples/Visible/<eXit>:

      • Enter shape [Disk/Rect] <Disk>:

        • Enter radius <0.0>: (Enter the radius of the disk.)

        • Enter Length <0.0>: (Enter length of the rectangle.)

        • Enter Width <0.0>: (Enter width of the rectangle.)

      • Enter Shadow Sample <16>:

      • Enter Shape Visibility [Yes/No] <No>:

 

Sharp

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

Soft Mapped

    Displays realistic shadows with soft edges.

    Enter map size [64/128/256/512/1024/2048/4096] <256>:

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

    Enter softness (1-10) <1>:

    Specifies the softness to use to calculate the shadow map.

Filter Color

Color

Enter true color (R,G,B) or enter an option: Index color/Hsl/<255,255,255>: Defines the color of the light.

  • True Color (RGB): The RGB color model is an additive color model in which red, green, and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue. The component values are stored as integer numbers in the range 0 to 255, the range that a single 8-bit byte can offer (by encoding 256 distinct values).

  • Index color: Specifies an AutoCAD Color Index color.

  • HSL: Specifies the color using three parameters Hue, Saturation and Lightness.

Exit

Concludes the command and creates the light.

Related Commands

Light - creates a new light in the drawing.

Lightlist -  displays the Drawing Explorer - Lights dialog window.

Pointlight -  creates a point light.

Render - calculates a photorealistic image of the 3D model.

Spotlight - creates a spot light.

Sunproperties - displays the Sun Properties of the Active Viewport editor in the Drawing Explorer - Lights dialog.

Weblight -  creates a web light.

 


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