V-Ray Light Gen

V-Ray Light Gen offers various lighting options. It can illuminate exteriors or interiors with natural light using the V-Ray Sun & Sky system or a Dome light for image-based lighting (IBL) setup. There are two main categories - Exterior and Interior. Selecting a scenario, applies the new settings automatically. The resulting lighting scenarios are presented as thumbnails that can be interactively applied to the scene. The HDR images used by Light Gen can also be used independently - applied to any regular dome light.

It is best to use V-Ray Light Gen after the modeling phase is complete and prior to texture/shading and adding other light sources (lamps). Light Gen disables all scene lights, applies Sun transformation to the default SketchUp SunLight, disables auto exposure and white balance in the Settings Camera, and modifies the ISO parameter.

When you first open V-Ray Light Gen, you will be presented with the following message. Note that to download the content, you need about 1200 MB of free disk space.

The HDR images for IBL are saved in the following locations:
windows: \Documents\V-Ray Material Library\AEC\hdrs
macOS: ~/Library/Application Support/ChaosGroup/V-Ray Material Library/AEC/hdrs

If there is a previous installation of V-Ray 5 for 3ds Max detected, the files will be saved in the already specified location.

Once the download is complete, the HDR assets remain permanently available.
Every time you start Light Gen, V-Ray will connect to the Chaos servers to validate the completeness of the downloaded assets and check for updates. If a connection cannot be established, you can choose to proceed using what is already available on your hard drive.
Note that you can change the directory and disable the automatic check for updates from the Configuration rollout.

Altitude Variations – Variates the altitude of the sun disc over the horizon.

Azimuth Variations – Variates the rotation of the sun around the up axis.

Thumbnails Size (px) –The thumbnails size in pixels.

Generate variants – The number of variants depends on the Altitude and Azimuth variations.

Load – Loads previously saved scenarios.

HDR mode is available only for the Exterior scenario.

Custom HDR set – Activates the use of custom HDR images for scenarios generation. Note that only .hdr and .exr image files in the specified folder are considered. Keep the option disabled to use the built-in environments.

Unique Styles – The number of present HDRs in the V-Ray installer.

Variations – Rotations per HDR.

Seed – The random variation of each HDR. Seed of negative 1 (-1) disables the randomization.

Thumbnails Size (px) – The thumbnails size in pixels.

Disable lights on application – Artificial lights in the scene are automatically disabled to match the result from the thumbnail. When disabled, artificial lights like Point, Rectangle, Sphere, Spot remain unchanged. The Sun and Dome lights are always disabled on application to ensure that the Light Gen environment is in full effect.

Stop – Stops the generation of variants.

Save – Saves a .lightset file. If loaded, the file shows the geometry in the thumbnails, but note that only the light source info is kept. It is recommended to use .lightset files saved with the same SketchUp version.

Reset – Returns to the initial screen of V-Ray Light Gen.