Simulation Cache

The Simulation Cache contains the positions, orientations, scales and joint orientations of each simulated Entity. It may also contains blendshapes, squatch and stretch scales, cloth vertices if any. The user can also choose additional PP attributes to export. Each frame of each exported CrowdField is saved as a Golaem Simulation Cache file (.gscf file per frame + one .gscs file per simulation) in the selected output directory.
 
Once exported, the cache can be reloaded for interactive replay and the entities it contains can be moved, added to kill list or imported as Maya joints and re-exported back into the simulation cache thanks to the Simulation Cache Proxy.
 
The Simulation Cache is also referenced in each Rendering Proxy to be passed to the procedural rendering plugin for geometry generation at render time.
 
 
Crowd Field Nodes List of all the available Crowd Fields. Only the Crowd Fields selected in this list will be exported.
Use Existing Simulation Cache

Avoids running the simulation if a simulation cache already exists, and only exports the FBX/renderer files.
Export Caa File Only

If checked, only the Crowd Assets Association file (.caa) is exported.
Cache Name Exported cache file name.
Start Frame First frame to export. If the selected Crowd Fields are started after this frame, the export will only start at the frame at which the Crowd Fields start.
End Frame Last frame to export.
PreExport Callback MEL/Python script command called just before the Simulation Export starts. If the callback code returns an error, the export process is cancelled.
PostExport Callback MEL/Python script command called just after the Simulation Export stops or fails
Additional Attributes Additional per particle attributes to export in the simulation cache. Attributes can be added using the + button and removed using the - button.
Note that the PP attributes used as shader attributes must be exported.

The default exported PP attributes are:

  • particleId
  • glmEntityType
  • rgbPP
Output Directory Directory in which the Simulation Cache files will be exported. It is possible to specify one directory per Crowd Field by manually setting each directory (separated by ";").

Export Command

When hitting export, this window issues a glmCrowdSimulationExporter command.

Name & Numbering Convention

The Golaem Simulation Cache files follow the following name template:

cacheName.crowdFieldName.frameNumber.gscf (one per crowdfield per frame)
cacheName.crowdFieldName.gscs (one per crowdField)

Golaem Cache Format

The Golaem Simulation Cache format is a binary format, using zip compression, in addition of quantization of positions and orientations. It is meant to reduce cache size on disk, and improve reading/writing efficiency.

If a Detach Behavior is used in the exported simulation or if a Character has some Squatch and Stretch properties, the quantization of positions will be disabled. This will result in greater frame size (usually around 50% bigger).

To handle data contained in Golaem Cache files, a low level API is available. See Golaem Simulation Cache API