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This page provides information about the Light Rectangle in V-Ray for Grasshopper.

Overview

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Input Parameters

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On (Boolean) – – Enables or disables the light source. Position 

plane (Point) – Sets the light source point position. If a list of input Positions is connected multiple lights are generated. Note: The number of input positions determines the lights count.Target (Point) – The Rectangle light Position and Target combined determine the light orientation vector. Base plane) – The rectangle light base plane, where its geometry is positioned and orientated along.

Color (Color)– Provides a slot to set a light source color. 

Intensity (Number) – Provides an option to control the light source intensity. Calculated in Default (Scalar) units. Calculated in the specified units.

Units (Integer) – Specifies the light unit of measurement. Using correct units is essential when working with physical camera exposure. The light automatically takes the scene units scale into consideration to produce correct result for the scale being worked in.

Default (Scalar) – The color and multiplier directly determine the visible color of the light without any conversion. The light surface appears with the given color in the final image when seen directly by the camera.
Luminous Power (Lumens) – Total emitted visible light power measured in lumens. The intensity of the light does not depend on its size. A typical 100W incandescent light bulb emits about 1500 lumens of light.
Luminance (lm/m^2/sr) – Visible light surface power measured in lumens per square meter per steradian. The intensity of the light depends on its size.
Radiant Power (W) – Total emitted visible light power measured in watts. The intensity of the light does not depend on its size. This is not the same as the electric power consumed by a light bulb. A typical 100W light bulb only emits between 2 and 3 watts as visible light.
Radiance (W/m^2/sr) – Visible light surface power measured in watts per square meter per steradian. The intensity of the light depends on its size.

Invisible (Boolean) – This option makes the light source invisible. It does not affect the light source's illuminance.

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U/V Size (Number) – Controls the U/V size of the light square measured in scene units.

Directionality Dir (Number) – Specifies the spread of the light beam. Value of 0 emits light equally in all directions. Increasing the value makes the light beam more narrow and concentrates it in one direction. 

Output Parameters

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Add Light (Generic Data)– Light output that can be connected to a V-Ray Render node component.

Example

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Light Rectangle component connection. Note that an Environment component with a black color plugged in the GI input parameter is used as an override to turn off the default Environment lighting. If there is no Environment input in the Render component V-Ray always creates one internally.

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Column width 20% 10% Column width 38%60% Image Added Image Removed Column width 42% Image Added   Rectangle Light node connection. Note the toggled off Simple Light Rig plugged used as an override. If there is no Light Rig input in the V-Ray Render component it will always internally create one.   Column width 20% 10%