Niagara Tutorial: Collision | UE Content Examples Reconstruction

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

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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

Collision queries are done with either line traces on the cpu or depth buffer/distance field checks on the gpu. the query results are saved and can also be used by subsequent modules.

This example shows a collision event being sent to a different emitter which spawns particles in response to that event.

4. Introduction

Collisions can optionally generate events using the "Generate Collision Event" module. These are only supported on the CPU.

Collisions work on both CPU and GPU emitters, though some options are different. For instance, only GPU emitters can sample the scene depth, or the global distance field.

CPU Collisions are quite expensive compared to GPU collisions, generally, and should be used sparingly.

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 CollisionGen, CollisionStick, and CollisionImpactHit, respectively.

CollisionGen generates events, CollisionStick generates ribbon particles based on events, and CollisionImpactHit generates sprite particles based on events.

9. Three Emitters

First, work on the CollisionGen 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 3.5.

Spawn 3.5 particle per second.

12. Initialize Particles

Select Initialize Particles and set:

1. Lifetime is 7.0
2. Color Mode is Direct Set
3. Sprite Size Mode is Uniform and has a value of 14.0

13. Add Velocity in Cone

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

14. Add Velocity in Cone

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

15. Add Velocity in Cone

Set the value type of Velocity Strength to Random Range Float

16. Add Velocity in Cone

1. Set Velocity Strength to a minimum value of 250.0 and a maximum value of 750.0.
2. Set the Cone Angle to 24.0.
3. Set the Cone Axis to (0, 0, 1).