Terminate a simulation
To stop a running simulation in Bifrost, you can either stop playback in the host scene using the Play button or press the Esc key. These methods have different effects.
Stop playback in the host scene
When you stop playback using the Play button in the host scene, no new frames will be queued up for computation. However, it might take some time to finish computing the current frame before you have control again and can resume editing the scene.
This method lets you resume playback from the last frame simply by clicking Play again. In the meantime you can, for example, navigate the view, adjust shading and lighting, and so on. You can even jump to different frames before returning to the last simulated frame to resume playback.
Note that if you modify the graph or its inputs, you need to resume playback from the first frame of the simulation.
Terminate with Esc
When you terminate a simulation by pressing the Esc key, Bifrost tries to shut down computations already in progress. This is useful for aborting a long simulation and lets you resume work almost immediately.
Not every computation is stopped right away. Some processes will continue to run and consume resources in the background until they are complete, even if you can interact with the graph and scene. The following messages get logged to the Maya Script Editor at the start and end of the termination sequence — a pause between them indicates that the graph took some time to terminate.
// Warning: Bifrost job terminating... (bifrostGraphShape1) //
// Warning: Bifrost job terminated. (bifrostGraphShape1) // Resume playback after terminating with Esc
To resume computation after terminating a graph, you must first step back one frame to the previous completed frame before restarting playback. It might occasionally be possible to resume playback from the last frame as well, but this is not guaranteed.
Resuming playback in this way after pressing Esc works only if you have turned on Options > Resumable after Esc Termination. This is off by default for new scenes to save memory.
As always, if you modify the graph or its inputs, you need to resume playback from the first frame of the simulation.