General
Parameters

VRayLightSphere

VRayLightDome
VRayLightRect
VRayLightIES

Notes

General

The VRayLight is a V-Ray specific light source plugin that can be used to create physically accurate area lights. There are four differnt types of VRayLight objects available for Maya. They are: VRayLightSphere, VRayLightDome, VRayLightRect, VRayLightIES.

Parameters

VRayLightSphere

The VRayLightSphere is a VRayLight object which has the shape of a sphere.

 

VRayLightSphereBasic Parameters

 

Enabled - turns the VRayLightSphere on and off.

 

Color Mode - allows you to chose the mode in which the color of the light will be specified.

 

Light Color - when the Color Mode is set to Color this parameter controls the color of the light. When using photometric units, this color is normalized so that only the color hue is used, whereas the light intensity is determined by the  Intensity Multiplier.

 

Temperature - when the Color Mode is set to Temperature this parameter controls the color of the light.

 

Intensity Multiplier - multiplier for the light color; this is also the light intensity in the units chosen by the intensity units parameter.

 

Units - allows you to choose the light units. Using correct units is essential when you are using the VRayPhysicalCamera. The light will automatically take the scene units scale into consideration to produce the correct result for the scale you are working with. The possible values are:  


Default (image)
- the color and multiplier directly determine the visible color of the light without any conversion. The light surface will appear with the given color in the final image when seen directly by the camera (assuming there is no color mapping involved).

 

Lumious power (lm) - total emitted visible light power measured in lumens. When this setting is used, the intensity of the light will not depend on its size. A typical 100W electric bulb emits about 1500 lumens of light.

 

Luminance (lm/m²/sr) - visible light surface power measured in lumens per square meter per steradian. When this setting is used, the intensity of the light depends on its size.

 

Radiant power (W) - total emitted visible light power measured in watts. When using this setting, the intensity of the light does not depend on its size. Keep in mind that this is not the same as the electric power consumed by a light bulb for example. A typical 100W light bulb only emits between 2 and 3 watts as visible light.

 

Radiance (W/m²/sr) - visible light surface power measured in watts per square meter per steradian. When this setting is used, the intensity of the light depends on its size.

 

Radius - the radius of the light source, measured in scene units.

 

Sphere segments - controls the quality of the light object when it is visible either directly or in reflections. A bigger number makes the sphere smoother.

 

Sampling

 

Subdivs - this value controls the number of samples V-Ray takes to compute lighting. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time. Note that the actual number of samples also depends on the DMC Sampler settings.

 

Light cutoff threshold - this parameter specifies a threshold for the light intensity, below which the light will not be computed. This can be useful in scenes with many lights, where you want to limit the effect of the lights to some distance around them. Larger values cut away more from the light; lower values make the light range larger. If you specify 0.0, the light will be calculated for all surfaces. 

 

Override motion blur samples - allows you to overide the default number of samples that will be used to sample the current light for motion blur.

 

Motion blur samples - when the Override motion blur samples is enabled this value will be used when sampling the motion blur created by the current light.

 

Shadows

 

Shadows - when on (the default), the light casts shadows. Turn this option off to disable shadow casting for the light.

 

Shadow bias - the Shadow bias moves the shadow toward or away from the shadow-casting object (or objects). If the value is too low, shadows can "leak" through places they shouldn't, produce moire patterns or create out-of-place dark areas on meshes. If the Shadow bias is too high, shadows can "detach" from an object. If the value is too extreme in either direction, shadows might not be rendered at all.

Shadow Color - this parameter controls the color of shadows for this light. Note that anything different from black is not physically correct.

 

Options

 

Invisible - this setting controls whether the shape of the VRayLight source is visible in the render result. When this option is turned off the source is rendered in the current light color. Otherwise it is not visible in the scene. Note that this option only affects the visibility of the light when seen directly by the camera or through refractions. The visibility of the light with respect to reflections is controlled by the Affect specular and Affect Reflections options.

 

No decay - normally the light intensity is inversely proportional to the square of the distance from the light (surfaces that are farther from the light are darker than surfaces which are closer to the light). When this option is on the intensity will not decay with distance.

 

Store with irradiance map - when this option is on and GI calculation is set to Irradiance map V-Ray will calculate the effects of the VRayLight and store them in the irradiance map. The result is that the irradiance map is computed more slowly but the rendering takes less time. You can also save the irradiance map and reuse it later.

 

Affect Diffuse - this determines whether the light is affecting the diffuse properties of the materials.

 

Affect Specular - this determines whether the light is affecting the specular of the materials. This means glossy reflections.

 

Affect Reflections - this determines whether the light will appear in reflections of materials. This means both perfect and glossy reflections.

 

Diffuse contribution - a multiplier for the effect of the light on the diffuse.

 

Specular contribution - a multiplier for the effect of the light on the specular.

 

Photon Emission

 

Photons subdivs - this value is used by V-Ray when calculating the Global Photon Map. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Diffuse multiplier - a multiplier for the diffuse photons

 

Caustics subdivs - this value is used by V-Ray when calculating Caustics. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Caustics multiplier -this value is a multiplier for the generated caustics by the selected light. Note that this multiplier is cumulative - it does not override the multiplier in the Caustics render roll-out section.

VRayLightDome

The VRayLightDome is a V-Ray light object that can be used for image based lighting. The light is coming from a hemispherical dome above the y-axis of the light.

 

Basic Parameters

 

Enabled - turns the VRayLightDome on and off.

 

Color Mode - allows you to chose the mode in which the color of the light will be specified.

 

Light Color - when the Color Mode is set to Color this parameter controls the color of the light. When using photometric units, this color is normalized so that only the color hue is used, whereas the light intensity is determined by the  Intensity Multiplier.

 

Temperature - when the Color Mode is set to Temperature this parameter controls the color of the light.

 

Intensity Multiplier - multiplier for the light color.

 

Dome Spherical - when on, this option causes the dome light to cover the entire sphere around the scene. When off (the default), the light covers a hemisphere only.

 

Use Ray Distance - when enabled the distance at which shadow rays are traced will be limited to the value of Ray Distance parameter.

 

Ray Distance - specifies the maximum distance to which shadow rays are going to be traced.

 

Sampling

 

Subdivs - this value controls the number of samples V-Ray takes to compute lighting. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time. Note that the actual number of samples also depends on the DMC Sampler settings.

 

Light cutoff threshold - this parameter specifies a threshold for the light intensity, below which the light will not be computed. This can be useful in scenes with many lights, where you want to limit the effect of the lights to some distance around them. Larger values cut away more from the light; lower values make the light range larger. If you specify 0.0, the light will be calculated for all surfaces.

 

Shadows

 

Shadow bias - the Shadow bias moves the shadow toward or away from the shadow-casting object (or objects). If the value is too low, shadows can "leak" through places they shouldn't, produce moire patterns or create out-of-place dark areas on meshes. If the Shadow bias is too high, shadows can "detach" from an object. If the value is too extreme in either direction, shadows might not be rendered at all.

 

Texture

 

Dome Tex - specifies an environment texture for the VRayLightDome object.

 

Use Dome Tex - this tells the light to use a texture for the VRayLightDome surface.

 

Texture resolution - specifies the resolution at which the texture is resampled for importance sampling.

 

Tex Adaptive - when this option is on V-Ray will adjust the number of samples taken for different parts of the texture depending on their brightness.

 

Viewport Display

 

Enable - when this option is checked the texture loaded in the Dome Tex slot of the dome light will be displayed as environment in the viewport

 

Hardware texture resolution - specifies the resolution at which the texture will be previewed in the viewport

 

Sphere object detail -

 

Convert to sRGB color space - when this option is enabled the environment texture will automatically be converted to the sRGB color space. This only affects the preview in the viewport.

 

Gamma - when the Convert to sRGB color space option is disabled this option allows you to specify a gamma value that is going to be applied to the environment texture in the viewport. This option only affects the preview of the texture in the viewport.

 

Options

 

Invisible - this setting controls whether the shape of the VRayLight source is visible in the render result. When this option is turned off the source is rendered in the current light color. Otherwise it is not visible in the scene. Note that this option only affects the visibility of the light when seen directly by the camera or through refractions. The visibility of the light with respect to reflections is controlled by the Affect specular and Affect Reflections options.

 

Store with irradiance map - when this option is on and GI calculation is set to Irradiance map V-Ray will calculate the effects of the VRayLight and store them in the irradiance map. The result is that the irradiance map is computed more slowly but the rendering takes less time. You can also save the irradiance map and reuse it later.

 

Affect Diffuse - this determines whether the light is affecting the diffuse properties of the materials.

 

Affect Specular - this determines whether the light is affecting the specular of the materials. This means glossy reflections.

 

Affect Reflections - this determines whether the light will appear in reflections of materials. This means both perfect and glossy reflections.

 

Diffuse contribution - a multiplier for the effect of the light on the diffuse.

 

Specular contribution - a multiplier for the effect of the light on the specular.

 

Photon Emission

 

Target radius - defines a sphere around the light icon where photons are being shot when photon-mapped caustics or the global photon map are used.

 

Emit radius - defines a sphere around the light icon from which photons are being shot towards the target radius area.

 

Photons subdivs - this value is used by V-Ray when calculating the Global Photon Map. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Diffuse multiplier - a multiplier for the diffuse photons

 

Caustics subdivs - this value is used by V-Ray when calculating Caustics. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Caustics multiplier -this value is a multiplier for the generated caustics by the selected object. Note that this multiplier is cumulative - it does not override the multiplier in the Caustics render roll-out section.

VRayLightRect

The VRayLightRect is a light source with the shape of a planar rectangle.

 

Basic Parameters

 

Enabled - turns the VRayLightRect on and off.

 

Color Mode - allows you to chose the mode in which the color of the light will be specified.

 

Light Color - when the Color Mode is set to Color this parameter controls the color of the light. When using photometric units, this color is normalized so that only the color hue is used, whereas the light intensity is determined by the  Intensity Multiplier.

 

Temperature - when the Color Mode is set to Temperature this parameter controls the color of the light.

 

Intensity Multiplier - multiplier for the light color; this is also the light intensity in the units chosen by the intensity units parameter.

 

Units - allows you to choose the light units. Using correct units is essential when you are using the VRayPhysicalCamera. The light will automatically take the scene units scale into consideration to produce the correct result for the scale you are working with. The possible values are:

 

Default (image) - the color and multiplier directly determine the visible color of the light without any conversion. The light surface will appear with the given color in the final image when seen directly by the camera (assuming there is no color mapping involved).

 

Lumious power (lm) - total emitted visible light power measured in lumens. When this setting is used, the intensity of the light will not depend on its size. A typical 100W electric bulb emits about 1500 lumens of light.

 

Luminance (lm/m²/sr) - visible light surface power measured in lumens per square meter per steradian. When this setting is used, the intensity of the light depends on its size.

 

Radiant power (W) - total emitted visible light power measured in watts. When using this setting, the intensity of the light does not depend on its size. Keep in mind that this is not the same as the electric power consumed by a light bulb for example. A typical 100W light bulb only emits between 2 and 3 watts as visible light.

 

Radiance (W/m²/sr) - visible light surface power measured in watts per square meter per steradian. When this setting is used, the intensity of the light depends on its size.

 

U Size - determines the width of the light measured in scene units.

 

V Size - determines the height of the light measured in scene units.

 

Sampling

 

Subdivs - this value controls the number of samples V-Ray takes to compute lighting. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time. Note that the actual number of samples also depends on the DMC Sampler settings.

 

Light cutoff threshold - this parameter specifies a threshold for the light intensity, below which the light will not be computed. This can be useful in scenes with many lights, where you want to limit the effect of the lights to some distance around them. Larger values cut away more from the light; lower values make the light range larger. If you specify 0.0, the light will be calculated for all surfaces.

 

Override motion blur samples - allows you to overide the default number of samples that will be used to sample the current light for motion blur.

 

Motion blur samples - when the Override motion blur samples is enabled this value will be used when sampling the motion blur created by the current light.

 

Shadows

 

Shadows - when on (the default), the light casts shadows. Turn this option off to disable shadow casting for the light.

 

Shadow bias - the Shadow bias moves the shadow toward or away from the shadow-casting object (or objects). If the value is too low, shadows can "leak" through places they shouldn't, produce moire patterns or create out-of-place dark areas on meshes. If the Shadow bias is too high, shadows can "detach" from an object. If the value is too extreme in either direction, shadows might not be rendered at all.

 

Shadow Color - this parameter controls the color of shadows for this light. Note that anything different from black is not physically correct.

 

Texture

 

Rect Tex - specifies the texture to use.

 

Use Rect Tex - his tells the light to use a texture for the light surface. If there are surfaces which are close to a texture-mapped light, it is best to have GI enabled. This allows V-Ray to use combined direct and indirect sampling for the light, reducing the noise for surfaces close to the light.

 

Texture resolution - specifies the resolution at which the texture is sampled when the Tex Adaptive option is checked.

 

Tex Adaptive - when this option is checked V-Ray will use impotance sampling on the texture in order to produce better shadows.

 

Options

 

Ignore light normals - normally, the surface of the source emits light equally in all directions. When this option is off, more light is emitted in the direction of the source surface normal.

 

No decay - normally the light intensity is inversely proportional to the square of the distance from the light (surfaces that are farther from the light are darker than surfaces which are closer to the light). When this option is on the intensity will not decay with distance.

 

Double Sided - this option controls whether light is beamed from both sides of the plane.

 

Invisible - this setting controls whether the shape of the VRayLightRect source is visible in the render result. When this option is turned off the source is rendered in the current light color. Otherwise it is not visible in the scene. Note that this option only affects the visibility of the light when seen directly by the camera or through refractions. The visibility of the light with respect to reflections is controlled by the Affect specular and Affect Reflections options.

 

Skylight Portal - when this option is on, the Color and Multiplier parameters are ignored; instead the light will take its intensity from the environment behind it.

 

Simple Skylight Portal - this option is only enabled if the Skylight Portal option is on. It tells the VRayLightRect that there is nothing of interest behind the light itself, and so the environment color can be used directly. Normally, the portal light takes its color from whatever objects are behind it. In order to do this, the light traces additional rays, which may slow down the rendering. Turning this option on makes the rendering of portal lights faster.

 

Store with irradiance map - when this option is on and GI calculation is set to Irradiance map V-Ray will calculate the effects of the VRayLightRect and store them in the irradiance map. The result is that the irradiance map is computed more slowly but the rendering takes less time. You can also save the irradiance map and reuse it later.

 

Affect Diffuse - this determines whether the light is affecting the diffuse properties of the materials.

 

Affect Specular - this determines whether the light is affecting the specular of the materials. This means glossy reflections.

 

Affect Reflections - this determines whether the light will appear in reflections of materials. This means both perfect and glossy reflections.

 

Diffuse contribution - a multiplier for the effect of the light on the diffuse.

 

Specular contribution - a multiplier for the effect of the light on the specular.

 

Photon Emission

 

Photons subdivs - this value is used by V-Ray when calculating the Global Photon Map. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Diffuse multiplier - a multiplier for the diffuse photons.

 

Caustics subdivs - this value is used by V-Ray when calculating Caustics. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Caustics multiplier -this value is a multiplier for the generated caustics by the selected object. Note that this multiplier is cumulative - it does not override the multiplier in the Caustics render roll-out section.

VRayLightIES

VRayLightIES is a special kind of VRay light that uses an .ies file to specify the shape of the light. An .ies file contains complete specifications of a real world light bulb or tube. They are usually provided by the manufacturer and the information in those files is gathered through lab experiments. V-Ray can use these files to create light sources that will act the same way as the real bulb.

 

Basic Parameters

 

Enabled - turns the light on and off.

 

IES File Name - allows you to choose an .ies file to use for the current light.

 

Color Mode - allows you to chose the mode in which the color of the light will be specified.

 

Light Color - when the Color Mode is set to Color this parameter controls the color of the light. When using photometric units, this color is normalized so that only the color hue is used, whereas the light intensity is determined by the  Intensity Multiplier.

 

Temperature - when the Color Mode is set to Temperature this parameter controls the color of the light.

 

Filter color - this is a color multiplier for the light.

 

Intensity - this is the intensitiy of the light.

 

Shadows

 

Shadows - when on (the default), the light casts shadows. Turn this option off to disable shadow casting for the light.

 

Soft Shadows - sometimes the .ies file contains information about the physical shape and size of the bulb. When this option is on the light will cast shadows according to this information. Otherwise the light will cast shadows as if it was a Point Light.

 

Shadow bias - the Shadow bias moves the shadow toward or away from the shadow-casting object (or objects). If the value is too low, shadows can "leak" through places they shouldn't, produce moire patterns or create out-of-place dark areas on meshes. If the Shadow bias is too high, shadows can "detach" from an object. If the value is too extreme in either direction, shadows might not be rendered at all.

 

Shadow Color - this parameter controls the color of shadows for this light. Note that anything different from black is not physically correct.

 

Sampling

 

Subdivs - this value controls the number of samples V-Ray takes to compute lighting. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time. Note that the actual number of samples also depends on the DMC Sampler settings.

 

Light cutoff threshold - this parameter specifies a threshold for the light intensity, below which the light will not be computed. This can be useful in scenes with many lights, where you want to limit the effect of the lights to some distance around them. Larger values cut away more from the light; lower values make the light range larger. If you specify 0.0, the light will be calculated for all surfaces.

 

Override motion blur samples - allows you to overide the default number of samples that will be used to sample the current light for motion blur.

 

Motion blur samples - when the Override motion blur samples is enabled this value will be used when sampling the motion blur created by the current light.

 

Options

 

Affect Diffuse - this determines whether the light is affecting the diffuse properties of the materials.

 

Affect Specular - this determines whether the light is affecting the specular of the materials. This means glossy reflections.

 

Area Speculars - when this parameter is enabled, the specular highlights will be computed with the real light shape as defined in the .ies files. For this to work you also have to enable Soft Shadows. When this parameter is disabled, the specular highlights will be computed using a point light approximation instead of the real shape.

 

Diffuse contribution - a multiplier for the effect of the light on the diffuse.

 

Specular contribution - a multiplier for the effect of the light on the specular.

 

Photon Emission

 

Photons subdivs - this value is used by V-Ray when calculating the Global Photon Map. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Diffuse multiplier - a multiplier for the diffuse photons.

 

Caustics subdivs - this value is used by V-Ray when calculating Caustics. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.

 

Caustics multiplier -this value is a multiplier for the generated caustics by the selected object. Note that this multiplier is cumulative - it does not override the multiplier in the Caustics render roll-out section.

 

Notes