--- title: "V-Ray Sun" canonical: "https://documentation.chaos.com/space/VC4D/116850807/V-Ray%20Sun" format: markdown --- This page provides information about the Sun in V-Ray for Cinema 4D. Overview The V-Ray Sun  and  V-Ray Sky  are special features which are provided by the V-Ray renderer. Developed to work together, the  V-Ray Sun  and  V-Ray Sky  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 V-Ray Sun. When using the V-Ray Sun in combination with the  V-Ray Sky , it is recommended to use directly the  V-Ray Sun and Sky  system, which is automatically set when created.  UI Path: ||V-Ray|| >  Lights > V-Ray Sun General Sun Enabled – Turns the sun light on and off. Intensity – Specifies the brightness of the sun. Since the sun is very bright by default, you can use this parameter to reduce its effect. This option is not available with V-Ray GPU. Size – 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. Filter Color – Shifts the hue of the V-Ray Sun and Sky system towards the specified color. This option is not available with V-Ray GPU. Color Mode – This mode affects the way the Filter Color hues the sun and sky light. Filter  – Shifts the V-Ray Sun and Sky hue towards the color specified by the Filter Color . Direct  – Takes the Filter Color for the V-Ray Sun light. In this case, the light intensity is controlled by the  Intensity multiplier and it does not depend on the Sun's position in the sky. Override  – Takes the Filter Color for the V-Ray Sun light, however the intensity is controlled by the position of the V-Ray Sun in the sky.  Sky Sky Model – Determines the procedural model used to generate the V-Ray Sky texture: 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 a clear sky. CIE Overcast  – The VRaySky procedural texture is generated based on the CIE method for a cloudy sky. Hosek et al.  – The VRaySky procedural texture is generated based on the Hosek et al. method.  PRG Clear Sky – The VRaySky procedural texture is generated based on the Improved method which has enhanced sunrise and sunset sky. Altitude  – Controls the observer's altitude in meters. As the altitude increases, sky clarity improves, and the horizon line becomes less defined. Ground Albedo – Sets the color of the V-Ray Sun and Sky system's ground. This option is not available with V-Ray GPU. Horiz Illum – Specifies the intensity (in lx) of the illumination on horizontal surfaces coming from the sky. This parameter is enabled when one of the CIE Sky Models are selected. This option is not available with V-Ray GPU. Blend Angle – Specifies the angle in degrees where blending occurs between the horizon line and sky. Values close to 0.0 produce a sharper horizon line, while larger values produce a softer horizon line. This option is not available with V-Ray GPU. Horizon Offset – Allows the user to manually lower the horizon line. Turbidity – Determines the amount of dust in the air, which in turn affects the color of the sun and sky. Smaller values produce a clear, blue sky and sun similar to what is seen in rural areas, while larger values make the sun and sky more yellow and orange as seen in a big city. This option is not available with V-Ray GPU. 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, while larger values make it bluer. This option is not available with V-Ray GPU. Clouds On – Enables the cloud system. Ground Shadows – When enabled, casts shadows from the clouds. See the Clouds Ground Shadows example for more information . 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 for more information. Variety  – Controls the variety of the cumulus and stratus types of clouds.  See the  Clouds Variety example  for more information. 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  Clouds Cirrus Amount example for more information. 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 for more information. Seed – Generates a random value, based on the given number, to change the pattern of the clouds and the  Contrails . Height (m)  – Determines the Clouds position in height. See the Clouds Height example for more information. Longitude Offset   (m) – Moves the cloud system by the X axis. See the Clouds Offset example for more information. Latitude Offset (m)  – Moves the cloud system by the Y axis. See the Clouds Offset example for more information. Longitude Phase (%)  – Controls the phase by the 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. Latitude Phase (%)  – Controls the phase by the 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. Enable Contrails  – When enabled, plane contrails are simulates in the sky. Number of Contrails  – Determines the number of contrails generated.  See the  Number of Contrails example  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 for more information. Contrails Distortion  – Determines the amount of distortion in the contrails.  See the  Contrails Distortion example  for more details. Contrails Offset Longitude/Latitude (m)  – Offsets the contrails by a given value, according to the X or Y axis.  See the  Contrails Offset example  for more information. Contrails Time  – Determines how long along their way the planes are.  See the  Contrails Time animation  for more details. Example: Clouds Density The Clouds Density parameter controls the amount of clouds in the sky. The higher the value, the more clouds appear in the render.  Clouds Density = 0 Clouds Density = 0.4 Clouds Density = 0.8 Example: Clouds Variety This example shows the effect of the Clouds Variety parameter on the clouds' distribution and look. Clouds Variety = 0 Clouds Variety = 0.5 Clouds Variety = 1 Example: Clouds Ground Shadows The Clouds Ground Shadows option controls whether or not the clouds cast shadows in the scene. Example: Clouds Cirrus Amount This example shows how increasing the Clouds Cirrus Amount increases the appearance of the cirrus clouds in the render. Clouds Cirrus Amount = 0 Clouds Cirrus amount = 0.5 Clouds Cirrus amount = 1 Example: Clouds Thickness The Clouds Thickness parameter specifies how full the clouds are. Lower values make them thinner and sheerer, while higher values make them look heavy.  Clouds Thickness = 200 Clouds Thickness = 500 Clouds Thickness = 800   Example: Clouds Offset The following example demonstrates how changing the Clouds Longitude Offset and the Clouds Latitude Offset parameters affects the appearance of the clouds. No offset Clouds Longitude Offset = -250, Clouds Latitude Offset = 0 Clouds Longitude Offset = -250, Clouds Latitude Offset = 500 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. Number of Contrails = 5 Number of Contrails = 20 Number of Contrails = 40 Example: Contrails Strength This example shows how the Strength parameter makes the contrails more visible and prominent in the sky. Contrails Strength = 0.1 Contrails Strength = 0.5 Contrails strength = 1.0 Example: Contrails Distortion The Contrails Distortion parameter is used to achieve some variety in the trace line. Contrails Distortion = 0.1 Contrails Distortion = 0.5 Contrails Distortion = 1.0 Example: Contrails Offset The Contrails Offset option introduces an offset along the X or Y direction in the sky. Contrails Offset Longitude = 0, Latitude = 0 Contrails Offset Longitude = 5000, Latitude = 0 Contrails Offset Longitude = 0, Latitude = 5000  Example: Contrails Time The frames in this animation show the Contrails Time parameter with values ranging between 0 and 2.0 , with a Step of 0.2 . Night Sky Night Sky creates a realistic procedural night sky, complete with the Moon, stars, and the Milky Way. As part of the Sun & Sky model, Night Sky enables users to create realistic nighttime environments based on their actual location. Just like with the V-Ray Sun, it is recommended to use Night Sky with the Physical Camera with suitable values to produce a correct result. When you enable the Night Sky’s Moon and/or Stars, the clouds become darker, as the Night Sky applies a filter to simulate nighttime. Moon Enable – Enables the appearance of the Moon in the night sky. The Moon is compatible with the PRG Sky Model only. This feature requires a V-Ray Sky to be present for the Glow to work. Additionally, V-Ray GPU requires V-Ray Sky to render the Moon. Size Multiplier - Controls the visible size of the Moon. Affects the appearance of the Moon disc as seen by the camera and reflections, as well as the blurriness of the Moon shadows. Direct Intensity Multiplier – Controls the brightness of the Moon as seen directly in the sky or in perfect mirror reflections/refractions. See the Direct Intensity Multiplier example for an illustration. Indirect Intensity Multiplier – Controls the intensity of the scene illumination cast by the Moon. See the Indirect Intensity Multiplier example for an illustration. Glow Multiplier – This is a multiplier for the glow around the Moon. A value of 0 disables the glowing effect. Moon Filter Color – The color tint for the appearance and illumination cast by the Moon. The default white (1, 1, 1) color means no change of color. Position Overrides Moon Guide Object – Allows a Guide Object to be used to determine the Moon’s Azimuth , Elevation, and Guide Distance . You can use the eyedropper tool or drag and drop an object from the Objects tab to set it as the Guide Object. Once the Guide Object is set, if you change the values of the Azimuth, Elevation, or Guide Distance properties, the Guide Object moves according to the new value. Add Guide Object – Creates a Nul object in the scene to serve as the Guide Object. Override Azimuth – Allows a custom Azimuth value to be input, if a Moon Guide Object is not added. Azimuth – Specifies the Moon azimuth angle measured from the scene North to Eastward. A value of 0 means it aligns with the -Z-axis, while 90 ° aligns with the X-axis or East.  Override Elevation – Allows a custom elevation value to be input, if a Moon Guide Object is not added. Elevation – Controls the angle between the Moon and the ground. A value of 0 makes the Moon exactly at the horizon, and a value of 90 makes the Moon in the zenith. Guide Distance – Override Phase – Allows a custom Phase value for the Moon to be input. Phase – Specifies the phase of the Moon, where a value of 0 is full Moon, 90 is first quarter, 180 is new Moon, and 270 is the last quarter. See the Phase example for an illustration. Override Rotation – Allows a custom rotation value for the Moon to be input. Rotation – Rotates the Moon disc in the sky, where zero makes it match the Moon’s appearance in its highest point when observed in the Northern hemisphere, and 180 corresponds to the Southern hemisphere. Stars Enable – Enables the appearance of stars in the night sky. This feature is only compatible with the PRG Clear Sky model, and VRaySky is present. Size Multiplier – Controls the size of the stars. A default value of 1 renders the stars with a radius of 1 pixel; a value of 2 makes the stars twice as large. If set to 0, the stars are rendered with the minimum size possible. Size Difference – Controls the size difference between faint and bright stars. When set to 0, all stars have the same size, and a value of 1 makes the brightest stars twice as large; the second-magnitude stars (e.g., Polaris) retain their size, while the faintest stars disappear. Direct Intensity Multiplier – Controls the brightness of the stars as seen directly in the sky or in perfect mirror reflections/refractions. See the Direct Intensity Multiplier example for an illustration. Indirect Intensity Multiplier – Controls the intensity of the scene illumination cast by the stars. See the Indirect Intensity Multiplier example for an illustration. Milky Way Multiplier – This is a multiplier of the brightness of the Milky Way. Date and Time Use Sun Tag – This option is available if the V-Ray Sun object has a Sun Expression tag applied. When this option is enabled, the Sun Expression tag is used instead to determine the date and time when setting the Night Sky settings. Time – Allows you to set the Date, Year and exact time to influence the look of the stars. Latitude – Determines the Night Sky latitude, where -90° means the sky shows over the South Pole, and 90° means the sky shows over the North Pole. Longitude – Determines the Night Sky longitude, where 0 is the Prime Meridian, and 90 is 90° to the East of the Prime Meridian. Time Zone – Determines the time zone, starting from Greenwich Time at 0. Set the hour offset, to simulate the corresponding time zone. Time DST – When enabled, Daylight Savings Time is also taken into account when determining the look of the stars. If the date is set to a day in July, for instance, the stars will be placed differently, than if the same day is taken in November. Night Sky Examples Moon Direct Intensity Multiplier The Direct Intensity Multiplier example shows how this parameter affects the Moon’s appearance in the scene. Direct Intensity Multiplier = 1 Direct Intensity Multiplier = 8 Direct Intensity Multiplier = 16 Indirect Intensity Multiplier In this example, the light of the Moon illuminates the house and the forest beneath. The Indirect Intensity Multiplier parameter controls the intensity of illumination. Indirect Intensity Multiplier = 1 Indirect Intensity Multiplier = 75 Indirect Intensity Multiplier = 150 Phase The Phase example illustrates the phase of the Moon depending on the specified value for the same parameter. Phase = 0 Phase = 60 Phase = 120 Stars Direct Intensity Multiplier The Direct Intensity Multiplier example shows how changing the value of this parameter affects the stars in the sky. Direct Intensity Multiplier = 10 Direct Intensity Multiplier = 25 Direct Intensity Multiplier = 50 Indirect Intensity Multiplier In this example, the light of the stars illuminates the house and the forest beneath. The Indirect Intensity Multiplier parameter controls the intensity of illumination. Indirect Intensity Multiplier = 1 Indirect Intensity Multiplier = 250 Indirect Intensity Multiplier = 500 Options 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 Sun affects the diffuse properties of the materials. Diffuse Contribution – Controls the Sun's contribution to the diffuse illumination. Affect Specular – Determines whether the Sun affects the specular of the materials. The multiplier controls the sun's contribution to specular reflections. Specular Contribution – Controls the Sun's contribution to the specular reflection. Affect Atmospherics – When enabled, the light influences the atmospheric effects in the scene. This option is not available with V-Ray GPU. Atmospherics Contribution – Determines the amount of influence the light has on the atmospheric effects. LPE Label  – Allows a label to be assigned, which can be used to reference the light in a  Light Path Expression . This is especially useful when working with the  Light Select render element  to evaluate custom light contribution in the scene. Shadows Shadows – When enabled, the objects in the scene cast shadows. Shadow Color/Texture – Specifies a color or a texture map for the shadows. This option is not available with V-Ray GPU. Shadow Bias – Moves the shadow toward or away from the shadow-casting object. Higher values move the shadow toward the object, 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. Atmos Shadows – When enabled, the atmospheric effects in the scene cast shadows. This option is not available with V-Ray GPU. Photon Emission Photon Radius – Determines the radius of the area in which photons are shot. This area is represented by the cylinder around the Sun's ray vector. This parameter has an effect when photons are used in caustics. Caustic Subdivs – Used by V-Ray when calculating Caustics. Lower values mean more noisy results but render faster. Higher values produce smoother results but take more time. This option is not available with V-Ray GPU. Caustic Mult – Used by V-Ray when calculating Caustics. This multiplier controls the brightness of the caustics. This option is not available with V-Ray GPU. Aerial Perspective Enabled – Turns the atmospheric effect on or off. Visibility Range (m) – Specifies the distance at which the fog has absorbed 90% of the light coming from objects behind it. Lower values make the fog appear more dense, while larger values reduce the effect of the aerial perspective. This option is calculated in meters. Atmospheric Layer Height (m) – Controls the height of the atmosphere layer. Lower values can be used for artistic effects. The value is in meters. Inscattered Light Multiplier – Controls the amount of sunlight scattered from the atmospheric effect. The default value of 1.0 is physically accurate; lower or higher values could be used for artistic purposes. Affect Environment – When disabled, the atmospheric effect is applied only to camera rays that hit actual objects but not to rays that hit the sky. This is because the VRaySky texture already takes into account the amount of scattered sunlight. However, it is possible to enable this option for artistic effects, especially with low visibility ranges. Affect Background – Specifies whether the effect is applied to camera rays that hit the background (if a background other than VRaySky is used). This option is enabled by default, but some interesting effects are possible when disabled. Affect Alpha – Specifies whether the effect is applied to camera rays that hit the alpha channel. This option is enabled by default, but some interesting effects are possible when disabled. Filter Color – Determines the color of the unscattered light. Primary Visibility – Specifies whether the effect is seen by the camera rays. When disabled, the Aerial Perspective effect is seen only by secondary rays (e.g., refractions, reflections, etc.). Project Project is used to create a list of objects that can be excluded (or included) from the light's effects, such as illumination or shadow casting. Mode – Specifies whether the objects in the list are considered included or excluded from the light's effects. Objects – Creates a list of objects to be excluded or included. When an object is added to the list, the icons appear, which determine how the light affects the object. The icon controls whether the emitted light affects the object. The icon controls whether the shadows caused by the light affect the object. The determines whether the object's children are affected. Cinema 4D Sun Tag V-Ray Sun works with Cinema 4D's Sun tag. You can use date and time to set the position of the sun. Click on the GIF to view it in full size