Attribute samplers

Attribute samplers exported from PopcornFX can be retrieved, setup and used in the plugin.
In Unreal, they are represented as structures.
You can see and edit their properties directly inside the effect asset, in the "PopcornFX Default Attributes" category
For example, here is what you can see in the effect editor after exporting a grid attribute sampler name "Grid":

This will define the default values for emitters using this asset.
Modifying properties here will not update emitters already placed in levels.
When editing effect assets and emitters, some properties cannot be modified because they need to match what your effect needs (here Order and Data type).

You also have the option to use an asset sampler instead, that can be shared between multiple effects, by checking this box:

You can create sampler assets in the content browser:

You can then select them in your effect attributes

When editing an asset sampler, you can modify every property freely, since they are not tied to a particular effect:

Some properties or property combinations cannot be exposed to the engine. In this case, the relevant properties will be highlighted and their tooltip will tell you what is wrong. When this happens, the attribute sampler will still work but fall back to its default setup (i.e. what you exported from the PopocornFX editor), and plugin features (like editing properties, blueprint functions, etc..) will most probably not work with it.