Particle System: Lights

1. Particle System: Lights

This tutorial has been verified using Unity 2019.4.14f1 LTS - https://learn.unity.com/tutorial/particle-system-lights-2019-3

By default, particles do not illuminate the environment or objects around them. There are times when adding a light to a Particle System makes the effect more impactful. One example is a flickering campfire that illuminates the ground and objects nearby. Another is a muzzle flash that lights up the end of a gun when it’s fired. In this workflow, you will create a Firefly effect that uses a light to illuminate the environment.

1. From the GameObject drop-down, select Effects > Particle System to create a new Emitter.

2. Create a new Texture for the Firefly (Figure 01).

Figure 01: Firefly Texture

3. Create a new additive Material and assign to it the Firefly Texture.

4. Assign the Material to your Particle System.

5. Adjust the parameters of your Particle System to imitate a Firefly’s motion. You may want to limit the number of particles you emit to optimize the Firefly effect. To do this, set your number of Max Particles to 10. Lights are expensive, so keep this in mind when using them in Particle Systems (Figure 02).

Figure 02: Firefly particle parameters with Max Particles set to 10

6. From the GameObject drop-down, select Light > Point Light to create a new Light. Particle Systems can use only Point Lights and Spot Lights (Figure 03).

7. In the Light, make sure Shadow Type is set to No Shadows for optimization purposes.

Figure 03: Point Light settings with Shadow Type set to No Shadows

8. Rename the Point Light “FireflyLight”.

9. Drag the FireflyLight into your Project folder to save it as a Prefab.

10. In your Particle System, enable the checkbox next to the Lights module.

11. Select the Lights module to expand it.

12. Drag the FireflyLight you created into the Light slot (Figure 04).

13. Set the Ratio to 1. This will make every Firefly use a Light.

14. Disable Random Distribution because all the fireflies will have a Light.

15. Disable Size Affects Range because the fireflies will all be about the same size.

16. Keep Use Particle Color enabled. The Lights will use the color that’s set in your Particle System.

17. Enable Alpha Affects Intensity so the Lights will fade on and off with the fireflies.

18. Adjust the Range Multiplier to shorten or lengthen the distance the lights cast.

19. Adjust the Intensity Multiplier to make the Lights brighter or dimmer.

Figure 04: Lights settings for fireflies

2. Conclusion

Adding Lights to a Particle System can make an effect more realistic by illuminating the objects and environment around it. Lights are a powerful feature that can enhance the visual quality of particle effects, though they can negatively impact the frame rate if too many are spawned on lower-end devices.