Emitters

Overview

A PopcornFXEmitter is an instance of a PopcornFX effect.
Emitters are updated and rendered in a PopcornFXScene, allowing group control over emitters.

Emitter properties

UE Plugin: Emitter details panel

  1. Simple controls on the PopcornFXEmitter and PopcornFXEffect:

    1. Start: starts the emitter if not already started

    2. Stop: stops the emitter if emitting

    3. Restart the emitter: stops and starts the emitter again

    4. Kill particles: kills particles and stops the emitter

    5. Reload: reloads the emitter from the effect it’s using

    6. Reimport: reimports the effect the emitter is using from its source and reloads it

  2. Source PopcornFXEffect

  3. PopcornFX Scene "name". An emitter can only play and render in one scene, identified by its name

  4. Effect attributes and attribute samplers that can be changed for this emitter from Blueprints or C++

PopcornFXEmitter

Drag and dropping a PopcornFXEffect in the scene will automatically create a PopcornFXEmitterActor properly setup:
UE Plugin: Drag and drop effect into level

Quick Tip: Disable Editor’s throttle

UE blocks viewport updates when UI events occur (changing a values, clicking buttons, …​).
This results in blocking the viewport update when tweaking attribute values, and can be annoying for fine tuning.
To disable this, enter the following command:

  • Slate.bAllowThrottling 0

If you want this setting to be set automatically when you start the editor, you can add the line Slate.bAllowThrottling=0 to the DefaultEngine.ini file in the Config/ directory of your project

UE Plugin: Disable Slate’s throttling

Blueprint / C++

To manually create a PopcornFX emitter in Blueprint or C++, you can:

  • Create a blueprint / actor that inherits from PopcornFXEmitter

  • Add a PopcornFXEmitterComponent to an actor/blueprint components list

  • Spawn an emitter with PopcornFX functions, fire and forget (see below)

Blueprint functions

Different functions are available on emitters
UE Plugin: Get/Set attribute value

Emitter functions

These functions allow you to modify the emitter state and create new instances.

  • Copy and Start Emitter at Location : Creates a copy of your emitter, and spawns it at a specific location and rotation (fire and forget)

  • Copy and Start Emitter Attached : Creates a copy of your emitter, and spawns it at a specific location and rotation, attached to a specific parent (fire and forget)

  • IsEmitter Alive / Emitting / Started : Helper functions to determine the current status of the emitter

  • Restart Emitter : Restarts the emitter (Terminate + Start)

  • Set Effect : Changes the source PopcornFXEffect of the emitter

  • Spawn Emitter Attached : Spawns an emitter at a specific location and rotation, attached to the specified parent (fire and forget)

  • Start Emitter / Stop Emitter : Respectively starts and stops the emitter

  • Terminate effect : Stops emission and unregisters the emitter

  • Toggle Effect : Starts or stops the emitter, depending on the given parameter

Here is an example of how to spawn an emitter (fire and forget):
UE Plugin: Spawn emitter

Attributes Functions

These functions allow you to manipulate emitter attributes.

  • Find Attribute Index : Returns the index of a specific attribute name

  • Get Attribute : Generic function to retrieve an attribute value. Specify the attribute by its index or its name

  • Reset Attributes to Default / Reset to Default Value : Reset your emitter attributes to their default values

  • Set Attribute : Generic function to modify an attribute value. Specify the attribute by its index or its name

Here are examples to Get / Set an attribute value:
UE Plugin: Get/Set attribute value