This page provides some information on how to get V-Ray up and running.
The V-Ray installer for Revit is straightforward and easy to follow. It can be downloaded from the V-Ray | Downloads section of the Chaos Group website (please make sure you use your login credentials to ensure access to the download links). Before installing V-Ray, it is recommended to check that your computer meets the System Requirements for running Revit with V-Ray. If you would like a step-by-step guide, please check out the Installation of V-Ray for Revit page.
Once V-Ray is installed you will want to make sure that your V-Ray license is properly configured. The Setting Up Your V-Ray License page includes everything you need to get V-Ray licensed and running properly.
Running V-Ray for the first time
By default, when Revit is launched, your V-Ray for Revit license will not be automatically engaged and you will see the V-Ray toolbar grayed out like below.
To pull your license and start using V-Ray, simply press the Acquire License button. To check if the license is engaged, simply click on the License Server button. This will launch the Online License Server homepage. When Revit is closed, your V-Ray license will be released automatically.
If you prefer your V-Ray license to be engaged automatically every time when Revit is loaded, use the Obtain license on start-up option.