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The VRaySun and VRaySky are special features which are provided by the V-Ray renderer. Developed to work together, the VRaySun and VRaySky reproduce the real-life Sun and Sky environment of the Earth. Both are coded so that they change their appearance depending on the direction of the VRaySun. Refer to the VRaySky page for more details about the texture.

The V-Ray Sun and Sky are based largely on the model presented in [ 1 ]the paper A Practical Analytic Model for Daylight. For a more complete list of references, please see the the References and links sectionsection.

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title UI Path: ||Create menu|| > Lights > V-Ray...
||V-Ray Toolbar|| > V-Ray Sun button > Click and drag in a viewport   ||V-Ray menu|| > Create > Lights > V-Ray Sun ||Create menu|| > Lights > V-Ray > V-Ray Sun > Click and drag in a viewport ||Command panel|| > Create tab > Lights > Choose V-Ray from dropdown > VRaySun > click and drag in a viewport

^{Image courtesy of Tamas Medve}

You can also specify the VRaySun as the sun type inside a 3ds Max Daylight system.

Enabled – Turns on and off the sun light.

Intensity multiplier¹ – An intensity multiplier for the VRaySun. Since the sun is very bright by default, you can use this parameter to reduce its effect. 

Size multiplier – Controls the visible size of the sun. This affects the appearance of the sun disc as seen by the camera and reflections, as well as the blurriness of the sun shadows. For more information, see The Size Multiplier Parameter example below.

Filter color – Changes the color of the sun and depends on the Color mode parameter.

Color mode – Affects the way the color in the Filter color parameter affects the color of the sun.

filter – Shifts the hue of the V-Ray Sun and Sky system towards the color specified in the Filter color field. 
direct – Sets the color of the V-Ray Sun to match the color in the Filter Color parameter. In this case the intensity of the light does not depend on the V-Ray Sun's position in the sky and is controlled through the intensity multiplier. 
override – Sets the color of the V-Ray Sun to match the color in the Filter Color parameter but the intensity of the light still depends on the V-Ray Sun's position in the sky.

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Sky model – Specifies the procedural model that is used to generate the VRaySky texture.

Hosek et al. – The VRaySky procedural texture is generated based on the Hosek et al. method.
Preetham et al. – The VRaySky procedural texture is generated based on the Preetham et al. method.
CIE Clear – The VRaySky procedural texture is generated based on the CIE method for clear sky.
CIE Overcast – The VRaySky procedural texture is generated based on the CIE method for cloudy sky.
PRG Clear Sky - The VRaySky procedural texture is generated based on the PRG Clear Sky method which has enhanced sunrise and sunset sky.

Ground albedo – Changes the color of the ground.

Indirect horiz. illum. – Specifies the intensity (in lx) of the illumination on horizontal surfaces coming from the sky.

Blend angle – Controls the size of the gradient formed by VRaySky between the horizon and the actual sky.

Horizon offset – Offsets the horizon from the default position (the absolute horizon).

Turbidity – Determines the amount of dust in the air and affects the color of the sun and sky. Smaller values produce a clear and blue sky and sun as you get in the country, while larger values make them yellow and orange as, for example, in a big city. For more information, see The Turbidity Parameter example below.

Ozone – Affects the color of the sun light. Available in the range between 0.0 and 1.0. Smaller values make the sunlight more yellow, larger values make it blue. For more information, see The Ozone Value example below.  

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Exclude – Excludes objects from illumination/shadow casting for the sun light.

Invisible – When enabled, makes the sun invisible, both to the camera and to reflections. This is useful to prevent bright speckles on glossy surfaces where a ray with low probability hits the extremely bright sun disk.

Affect diffuse – Determines whether the VRaySun is affecting the diffuse properties of the materials.

Affect specular – Determines whether the VRaySun is affecting the specular of the materials. The multiplier controls the suns contribution to specular reflections.

Affect atmospherics² – Specifies whether the light influences the atmospheric effects in the scene. The value determines the amount of involvement.

Cast atmospheric shadows – When enabled, the atmospheric effects in the scene cast shadows.

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Shadow bias – Moves the shadow toward or away from the shadow-casting object (or objects). Higher values move the shadow toward the object(s), while lower values move it away. If this value is too extreme, shadows can "leak" through places they shouldn't or "detach" from an object. Other effects from extreme values include moire patterns, out-of-place dark areas on surfaces, and shadows not appearing at all in the rendering. For more information, see The Shadow Bias example below.  

Photon emit radius – Determines the radius of the area where photons would be shot. This area is represented by the green cylinder around the Sun's ray vector. This parameter has effect when photons are used in caustics. See the Photon Emission Radius example for more information.

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Clouds on – Enables the cloud system.

Ground shadows – When disabled, the entire scene is covered by a single shadow or fully illuminated depending on whether the sun is blocked by a cloud at the current camera position. This is useful for smaller scenes and speeds up the rendering process. When enabled, V-Ray calculates the shadows precisely at every point of the scene. This provides a lot more definition to the shadows but may slow down the rendering process. It is helpful in larger scenes where the effect of the clouds is more visible. See the Clouds shadows example below.

Density – Controls the density of the cumulus and stratus types of clouds. A value of 1 fills up the sky with clouds. See the Clouds Density example below.

Density multiplier – A multiplier to the Density parameter. The larger the value, the darker the sky becomes at the horizon. Setting a value of 0 results in no clouds, regardless of the Density value.

Variety – Controls the variety of the cumulus and stratus types of clouds. See the Clouds Variety example below.

Seed – Generates a random value, based on the given number, to change the pattern of the clouds and the Contrails.

Cirrus amount – The maximum value of 1 fills the sky with cirrus clouds. Decreasing the value, lowers the presence of such clouds. When set to 0, the cirrus clouds are completely gone. See the Cirrus Amount example below.

Offset X (m) – Moves the cloud system by X axis. See the Clouds Offset example below.

Offset Y (m) – Moves the cloud system by Y axis. See the Clouds Offset example below.

Height (m) – Clouds position in height. See the Clouds Height example below.

Thickness (m) – Lower values make the cumulus and stratus types of clouds thin and sheer/lucent, while higher values make them full and heavy. See the Clouds Thickness example below.

Phase X (%) – Controls the phase by X axis, can be used to fine-tweak the cumulus and stratus clouds appearance. The appearance of the clouds loops at 0, 100, 200, etc. This parameter can be animated to resemble natural clouds appearance. See the How to add and animate clouds, without an HDRI example below.

Phase Y (%) – Controls the phase by Y axis, can be used to fine-tweak the cumulus and stratus clouds appearance. The appearance of the clouds loops at 0, 100, 200, etc. This parameter can be animated to resemble natural clouds appearance. See the How to add and animate clouds, without an HDRI example below.

Enable contrails – When enabled, plane contrails are simulated in the sky.

Number of contrails – Determines the number of contrails generated. See the Number of Contrails example below for more information.

Contrails strength – Determines the opacity of the contrails. Lower values create less opaque trails, which look older. See the Contrails Strength example below for more information.

Contrails distortion – Determines the amount of distortion in the contrails. See the Contrails Distortion example below for more details.

Contrails offset X/Y (m) – Offsets the contrails by a given value, according to the X or Y axis. See the Contrails Offset example below for more information.

Contrails time – Determines how far the contrails progress along the sky. See the Contrails time animation below for more details.

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Example: Cirrus Amount

This example shows how increasing the Cirrus Amount increases the appearance of the cirrus clouds in the render.

Image slider
Panel borderStyle none Cirrus amount = 0 Panel borderStyle none Cirrus amount = 0.5 Panel borderStyle none Cirrus amount = 1

Move the slider to see the example renders.

Example: Clouds Height

This example shows how the clouds change their position in the sky with increasing the Height value. 

Image slider
Panel borderStyle none Height = 500 Panel borderStyle none Height = 1000 Panel borderStyle none Height = 1500

Move the slider to see the example renders.

Example: Clouds Thickness

The Thickness parameter specifies how full the clouds are. Smaller values make them thinner and sheerer, while higher values make them look heavy. 

Move the slider to see the example renders.

Example: Clouds Offset

The following example demonstrates how changing the Offset X and Offset Y parameters affects the appearance of the clouds.

Move the slider to see the example renders.

Example: Number of Contrails

Note that the contrails are spread randomly across the sky. In most cases, the camera does not capture all of the contrails.

Move the slider to see the example renders.

Example: Contrails Strength

This example shows how the strength parameter makes the contrails more visible and prominent in the sky.

Image slider
minLabel 0.1 startIndex 1 maxLabel 1.0
Panel borderStyle none Contrails strength 0.1 Panel borderStyle none Contrails strength 0.5 Panel borderStyle none Contrails strength 1.0

Move the slider to see the example renders.

Example: Contrails Distortion

The Contrails distortion parameter is used to achieve some variety in the trace line. Move the slider to see the example renders.

Example: Contrails Offset

The Contrails offset option introduces an offset along the X or Y direction in the sky. Move the slider to see the example renders.