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Table of Contents

This page includes details about the Sky texture used for the environment within the V-Ray Sun and Sky System.


Overview


The V-Ray Sky texture map is typically used as an environment map to help simulate outdoor lighting. The texture changes its appearance based on the position of the V-Ray Sun Light, which is normally used in conjunction with the V-Ray Sun and Sky System. The example below on the left is a swatch of the sky map with a visible horizon line and ground. The renders to the right show a chrome shader ball and a diffuse shader ball with the V-Ray Sky texture map as an environment along with sun lighting.





Parameters


Find Sun Automatically – When enabled, attaches the sun automatically and takes settings from it.

Sun – Creates a connection between a VRaySun and the VRaySky object to calculate its appearance.

Overwrite Sun Settings – Overwrites the VRaySun Settings that would otherwise be taken from the Sun node. This is useful when using the VRaySky without a Sun node.

Sky Settings

Invisible – Controls whether the shape of the Dome Light source is visible in the resulting render. When disabled, the source light is rendered in the current light color, otherwise the light source itself is not visible in the scene.

Note: This parameter 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.

Sky Model – Determines the procedural model that is used to generate the V-Ray Sky texture:

Preetham et al. – When selected, the  V-Ray Sky procedural texture is generated based on the Preetham et al. method. 
CIE Clear
 
– When selected, the V-Ray Sky procedural texture is generated based on the CIE method for clear sky.
CIE Overcast – When selected, the V-Ray Sky procedural texture is generated based on the CIE method for cloudy sky.
Hosek et al – When selected, the V-Ray Sky procedural texture is generated based on the Hosek et al. method and uses a different ground and sky gradient.
PRG Clear SkyThe V-Ray Sky procedural texture is generated based on the PRG Clear Sky method which has enhanced sunrise and sunset sky.

See the Sky Model Types example below for more information.

Intensity Multiplier – Determines the intensity value when overwriting the sun settings. For more information, see the Intensity Multiplier example on the V-Ray Sun Light page.

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 example on the V-Ray Sun Light page.

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 example on the V-Ray Sun Light page.

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 example on the V-Ray Sun Light page.

Water Vapour – Controls the amount of water vapor in the atmosphere which affects the sky color.

Color – Shifts the hue of the V-Ray Sun and Sky system towards the color specified in the field.

Color Mode – Specifies how the Filter Color 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.

Ground Albedo – Sets the ground color of the V-Ray Sun and Sky system.

Horiz. Surface Illum. – Specifies the intensity (in lx) of the illumination on horizontal surfaces coming from the sky. Note: Only available when CIE Overcast or CIE Clear are selected as the Sky model.

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

Blend Angle – Controls the size of the gradient formed by V-Ray Sky between the horizon and the actual sky.




Example: Sky Model Types


The examples below show the different sky model types. Here, default values for V-Ray Sky have been used.



Preetham et al.

CIE Clear

CIE Overcast

Hosek et al.

PRG Clear Sky