V-Ray Light Gen

V-Ray Light Gen automatically generates a variety of lighting scenarios to choose from. 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. The resulting lighting scenarios are presented as thumbnails that can be interactively applied to the rendered view.

Selecting a scenario, applies the new settings automatically. On application, all artificial lights are switched off, the Sun azimuth and altitude of the rendered Revit view are modified and auto camera settings, like exposure and white balance, are disabled. The HDR images used by Light Gen can also be used independently - applied to the dome light.

When Light Gen option is applied to a scene, note that all artificial lights (that is, without V-Ray Sun) are automatically disabled. Objects with emissive material(s) and lights that are part of proxy scenes continue to illuminate.

||Revit Ribbon|| > V-Ray tab > Lighting panel (dropdown menu) > Light Gen

When you first open V-Ray Light Gen, you are 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 \Documents\V-Ray Material Library\AEC\hdrs

If there is a previous installation of V-Ray 5 for 3ds Max detected, the files are 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 connects to the Chaos servers to validate the completeness of the downloaded assets and checks 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 Config.json file.

After the download is completed, select between Exterior or Interior lighting. Each option has a set of parameters.

SUN & SKY

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.

HDR

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.

Generate Variants – Generates a number of scene light variants.

Load – Loads previously saved scenarios.

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 Rrevit version.

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