Physical Sun - turns on and off the sun light.

Sun invisible - when on, this option 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.

Atmosphere shadows - lets you determine whether atmospheric effects, such as fog, can cast shadows.

Physical Sky - turns on and off the sky light and environment.

Sky intensity multiplier - this is an intensity multiplier for the Physical Sky. The multiplier can be set to greater than 100%. Note that Physical Sky intensity increasing does not affect Physical Sun brightness intensity.

Override Background Env - when this option is unchecked Physical Sky has no effect to Background and Background from Enviroment tab will be visible on render.

Override GI Env - when this option is unchecked Physical Sky has no effect to GI Enviroment and GI Enviroment from Enviroment tab will be visible on render.

Override Refl. Env - when this option is unchecked Physical Sky has no effect to Reflection and Reflection from Enviroment tab will be visible on render.

Override Refr. Env - when this option is unchecked Physical Sky has no effect to Refraction and Refraction from Enviroment tab will be visible on render.

Convert to Grayscale - This will automatically convert sky to grayscale.

Gamma Correction - correct gamma value for Physical Sky.

Contrast Correction - correct contrast value for Physical Sky.

Hue Offset -

Hue Gain -

Saturation Offset -

Saturation Gain -

Lightness Offset -

Lightness Gain -

CIE Sky Model - Allows you to specify the procedural model that will be used to generate the VRay Sky.

• Default - default mode.
• CIE Clear sky - when this mode is selected the VRaySky procedural texture will be generated based on the CIE method for clear sky.
• CIE Overcast sky - when this mode is selected the VRaySky procedural texture will be generated based on the CIE method for cloudy sky

Horizon illumination for Phys Cam - specifies the intensity (in lx) of the illumination on horizontal surfaces coming from the sky. This value affects only on VRay Physical Camera Tag.

Horizon illumination for Std Cam - specifies the intensity (in lx) of the illumination on horizontal surfaces coming from the sky. This value affects only on Cinema4D Camera render, even if it have VRay Physical Camera Tag on it.

Turbidity - this parameter 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 further info, please see the Examples section.

Ozone - this parameter 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 further info, please see the Examples section.

Water vapour - aqueous vapor, is the gas phase of water. Water vapor is one state of the water cycle within the hydrosphere. Not used in current version.

Intensity multiplier for Phys Cam - this is an intensity multiplier for the Physical Sun. Since the sun is very bright by default, you can use this parameter to reduce its effect. This multiplier affects only on VRay Physical Camera Tag.

Intensity multiplier for Std Cam - this is an intensity multiplier for the Physical Sun. Since the sun is very bright by default, you can use this parameter to reduce its effect. This multiplier affects only on Cinema4D Camera render, even if it have VRay Physical Camera Tag on it.

Size Multiplier - this parameter 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.

Photon emit radius - determines the radius of the area, in where photons would be shot.

Photon emit distance - determines the distance of the area, in where photons would be shot. This area is represented by the green cyllinder around the Sun's ray vector. This parameter has effect when photons are used in the GI solutions or caustics.