Atoms cache XPU (AtomsUnreal)

In Atoms you can save your XPU simulation to an asset and reuse this asset with the cacheReaderXPU component. For more information about the animation XPU system, please have a look here XPU Animation

Exporting a cache

Before you can export a cache you have to set up a level sequence. Create one from the viewport menu.

Then open the sequence into the sequencer and drag and drop the agent groups you want to export.

For each agent group, add a new track for the "Static Frame" property:

Set two or more key frames making sure their value matche the frame number they are on. Set the interpolation of all key frames to linear or the exported simulation won't look right.

Now add a track for the “Use Static Frame“ property and set it to true. Otherwise, the agent group will not be driven by the sequence.

Open the Atoms Cache Exporter via the Atoms Crowd Toolbar Button: Exporters > Cache Exporter

There are a few options in the UI:

Level sequence
Output path
Start Frame: cache start frame
End Frame: cache end frame
Metadata

Select the sequence you just created from the Level Sequence property widget.

This will fill the widget above with all the agent groups controlled by the level sequence.

Now select the agent groups you want to export in a cache and press the right arrow icon.

This creates a tree, where the tom item is the name of the cache you are going to export. And the children are the agent groups this cache will contain.

Right-click on the cache name to rename it or delete it. You can also use the small bin bottom to remove agent groups from a cache or the cache from the list.

If you want to add an agent group from an existing cache, select the cache from the right widget, the agent group format the left widget and pres the little right arrow button.

You can export multiple caches at the same time. Just add them to the list.

Set now a valid output path where the exporter is going to write caches. Se the start frame and end frame and press the export button.

By default, the XPU cache exporter saves only the base agent metadata plus any metadata you set on the “perInstanceMetadata“ and heroMetadata property on each agent group. If you need to store other metadata, you need to add them to the metadata list. Write the metadata name inside the text field and press return or the + button to add it to the list. Right-click on a metadata name if you want to remove or rename it.