Atoms cache (AtomsUnreal)

In Atoms you can save your simulation on disk using Atoms caches. It is possible to reuse these caches with the cacheReader behaviour module or with an Atoms Cache Actor.

You can also tweak your caches with the cache reader module in combination with the Layout Tool or use other behaviour modules.

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

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.

Importing a cache

To import a cache from the disk, just drag and drop the file with no padding (i.e. mycache.atoms) inside the content browser.

When importing a cache, Atoms will search for existing Agent Type assets. You can choose to use the existing agent types or import new ones using the agent type from the cache.

It now generates an atoms cache asset. This asset doesn’t contain agent data but only a reference to the file on disk.