There are two types of licenses used by Carbon in Maya: the interactive (UI) license and the non-interactive (Batch) license.

When using floating licenses through a dedicated license server, it can be useful to understand the differences between these two types of license.

The Carbon interactive licenses are the less greedy of the two type of licenses, and are checked out per machine allowing you to run simultaneously multiple sessions on one machine without requiring additional licenses.

Note

This type of license can also allow the Carbon simulation to run in non-interactive sessions, but only if the environment variable NUMERION_FARM_UI_LICENSE is not set, or is set to any value other than 0.

The license is only checked out when a Carbon Simulation node is present. This could happen at its creation or when a scene containing such a node is loaded.

When no interactive license is available, the Carbon Simulation node will then fail to compute and a message similar to the following message will get displayed in the Carbon Simulation’s License Status section:

Warning: Carbon failed to find a valid license in the following locations: C:\Users\UserName\Documents\numerion;
Carbon license checkout failed. Error code: 9


The Carbon batch licenses are checked out per process, therefore two different non-interactive Maya sessions running on the same machine will require two Carbon batch licenses.

Note

Loading a Maya scene containing multiple Carbon Simulation nodes will still only use one license as these Carbon simulations will run within the same process.

When a non-interactive Maya session runs a Carbon simulation (through Render.exe or mayabatch.exe for example), batch licenses are always used first in preference to UI licenses. When no Carbon batch licenses are available, the Carbon simulation will then look for a Carbon UI license and use one if there is one available, but only if the environment variable NUMERION_FARM_UI_LICENSE is not set, or is set to any value other than 0.

Running a Carbon simulation using for example Render.exe when no Carbon licenses are available will trigger an output on the first frame of the simulation similar to this:

NUMERION_FARM_UI_LICENSE is not set, or is set to any value other than 0

No Carbon Batch license available. Trying Carbon UI license instead.
Warning: Carbon failed to find a valid license in the following locations: C:\Users\UserName\Documents\numerion;
Carbon license checkout failed. Error code: 9


Warning: Carbon failed to find a valid license in the following locations: C:\Users\UserName\Documents\numerion;
Carbon license checkout failed. Error code: 9


Since there is no license, nodes like Carbon Cloth that export simulated geometry to a shape, will not export any geometry, which results in empty shapes and warnings like this:

Warning: line 0: TrenderPolyShape::sample: mesh 'outputClothShape1' delivered an empty surface.


## Automatic Check-in¶

After 2 hours of inactivity from the Carbon Solver (no compute on the Carbon Simulation node), all licenses will get automatically returned.

Note

If after that the Carbon simulation is re-started, it could fail if licenses have been taken by other users in the meantime.