V-Ray Sun

The V-Ray Sun uses data from Revit to place the sun and render the image.

V-Ray supports all Revit sun position capabilities:

Still solar study: uses the location of the project in conjunction with the time of day/year to accurately place the sun in the sky.

Single Day: for more information, see Render Solar Study page.

Multi-Day: for more information, see Render Solar Study page.

Lighting solar study: simple azimuth and altitude settings.

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

Sun 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.

Sun Filter – Shifts the hue of the Sun Light system towards the color specified in the field.

Show Sun Disk – Controls the visibility of the sun disk.

Sky

Sky Model – Specifies the procedural model that is used to generate V-Ray Sky texture.

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

Horizontal Illum. – Specifies the intensity (in lx) of the illumination on horizontal surfaces coming from the sky.

Turbidity – Determines the amount of dust in the air and affects the color of the sun and sky. Smaller values produce a clear, blue sky and sun as seen in rural areas, while larger values make them yellow and orange as seen in big cities.

Ozone – Affects the color of the light. Values closer to 0.0 make the sunlight yellow, and values closer to 1.0 make it blue.

Ground Albedo

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

Blend Angle – Specifies the angle in degrees where blending will occur between the horizon line and sky. Values close to 0.0 produce a sharper horizon line, while larger values produce a softer horizon line.

Horizon Line – Allows the user to manually lower the horizon line.

Background

Background – You can choose between None, Custom, and Revit.

Brightness – Controls the brightness (color intensity) of the background.

Solid Color – Specifies a solid color to be used as background.

Image – Allows you to use an image file as background and makes the following parameters available:

Placement – You can choose between Spherical and Screen placement.

Rotate H and Offset V are available for the Spherical placement. 

Rotate H – Specifies the rotation of the image in degrees.

Offset V  – Specifies the vertical offset of the image.

Offset X, Offset Y, Scale X, and Scale Y are available for the Screen placement.

Offset X & Offset Y – Offset the image in a coordinate system manner where X is the horizontal direction and Y the vertical one .
Scale X & Scale Y – Scale the image. The lock icon locks the proportions of the image so that it is not distorted during scale. 

Background Image Preview – Previews the image. The arrows at the right corner allow you to flip the image.