Now that we know how to set the computation parameters and know what we want to compute, we can start with computing the Umbra 3 Tome. The created visibility data is stored in the Tome, which is accessed during runtime.
This is the part where you first need the Umbra license key. Place the umbra_license.txt in the working directory of the Umbra Debugger, or if you are using your own content pipeline integration or the Umbra 3 command line tool, in their respective working directories.
To start the computation, click the "Compute" button in the "Computation" tab. After doing so, the button will be replaced by a progress bar that indicates the completion percentage.
The initial computation time should be no greater than a few minutes even for large scenes. If it looks that the computation is taking too long, increase the Smallest Occluder and Smallest Hole computation parameter values.