Niagara Tutorial: Location Events | UE Content Examples Reconstruction

Version: 4.26, 中文
Created: 2021-02-24, Updated: 2021-03-25
Author: Cyanhall
👉

1. Preparation

This is the effect we are going to make in this tutorial.

Note: The main content of this tutorial comes from the Content Examples that come with Unreal Engine

Tip: Use ⬆️ ⬇️ to turn the page up and down. We recommend browsing with a large screen for a better reading experience.

Full Tutorials:

1. UE Niagara: Simple Sprite Emitter
2. UE Niagara: Simple Mesh Emitter
3. UE Niagara: Simple GPU Emitter
4. UE Niagara: Sprite Facing
5. UE Niagara: Blend Attributes By Value
6. UE Niagara: Static Beams
7. UE Niagara: Dynamic Beams
8. UE Niagara: Multiple Renderers
9. UE Niagara: Location Events
10. UE Niagara: Expressions

3. Introduction

In this example, a lead particle emitter is sending its location as an event to the other two emitters in the system, which allows them to spawn from that location.

This event is sent at the very end of the update after the particle's position and velocity are solved.

4. Introduction

Currently, Events are CPU Emitter Only!

On GPU Emitters, we do have a Lead/Follower paradigm using the "Spawn Particles From Other Emitter" and "Sample Particles From Other Emitter" modules which utilize the Particle Attribute Reader. There is an example of these behaviors in action in the Niagara_Advanced hallway.

5. Let's start the reconstruction

Right click and select FX => Niagara System to create.

6. Create Niagara System

Select Empty template, click + three times and click Finish

7. Create Niagara System

As a result, we get a Niagara System asset, click to open it.

8. Three Emitters

You can see that we have three emitters, renaming them LocEventGen, EventReceiveRibbon, and EventReceiveSprite, respectively.

LocEventGen generates events, EventReceiveRibbon generates ribbon particles based on events, and EventReceiveSprite generates sprite particles based on events.

9. Three Emitters

First, work on the LocEventGen stack.

10. Spawn Rate

Click on the + sign to the right of the Emitter Update to add the Spawn Rate module.

Spawn Rate: Number of particles per second to spawn.

11. Spawn Rate

Set the Spawn Rate value to 1.333.

Spawn 1.333 particle per second.

12. Initialize Particles

Select Initialize Particles and set:

1. Lifetime Mode is Random, then set the minimum value to 3.0 and the maximum value to 3.5
2. Color Mode is Direct Set
3. Sprite Size Mode is Uniform and has a value of 14.0

13. Sphere Location

Add the Sphere Location module in the Particles Spawn section.

14. Sphere Radius

Set Sphere Radius to 8.0

15. Add Velocity in Cone

Add Add Velocity in Cone module to the Particle Spawn section.

16. Add Velocity in Cone

Click the first Fix issue button to add its dependency on the SolveForcesAndVelocity module.

17. Add Velocity in Cone

Set the value type of Velocity Strength to Random Range Float

18. Add Velocity in Cone

1. Set Velocity Strength to a minimum value of 165.0 and a maximum value of 350.0.
2. Set the Cone Angle to 36.0.
3. Set the Cone Axis to (0, 0, 1).

19. Gravity Force

Set the value of Gravity to (0, 0, -300).

20. Gravity Force

Click the first Fix issue button to fix the SolveForcesAndVelocity module's dependency order issue.

21. Gravity Force

Set the value of Gravity to (0, 0, -300).

22. Generate Location Event

Add Generate Location Event module to the Particle Update section.

23. Persistent IDs

Check Requires Persistent IDs to obtain persistent IDs so that the generated events can be received by other emitters.

24. Three Emitters

Next, work on the EventReceiveRibbon stack.

25. Initialize Ribbon

Add Initialize Ribbon module to the Particle Spawn section.

26. Color

Add Color module to the Particle Update section.

27. Color

Set the value type of Color to Color from Curve

28. Color

Double-click the red circled dot and select a color

29. Color

At the location of the small red circle, right click and select Add key to all curve

30. Color

Double-click on the dot in the red circle and select another color

31. Event Handler

Click the + sign to add an event handler.

32. Event Handler

Set the event source to LocEventGen.LocationEvent.

33. Event Handler

1. Set Execution Mode to Spawned Particles
2. Set Spawn Number to 1.

34. Receive Location Event

Add Receive Location Event module to the Event Handler section.

35. Receive Location Event

Check Inherit Parent Normalized Age.

36. Remove Sprite Renderer

Select Sprite Renderer, right-click, and select Delete.

37. Ribbon Renderer

Add Ribbon Renderer module to the Render section.

38. Ribbon Renderer

Set the value of Material to DefaultRibbonMaterial

39. Three Emitters

Last, work on the EventReceiveSprite stack.

40. Initialize Particles

Select Initialize Particles and set:

1. Lifetime Mode to Random, then set the minimum value to 0.875 and the maximum value to 1.25
2. Color Mode as Direct Set3. Sprite Size Mode is Random Uniform and has a minimum value of 2.5 and a maximum value of 6.0.