You created a basic sprite effect by completing the Create a Sprite Smoke Effect in Niagara tutorial. In this tutorial, learn how to duplicate an emitter, create a Niagara system from a pre-existing emitter, and make further adjustments to change the look of the smoke.
Prerequisite Steps:
This how-to uses the M_smoke_subUV Material, which can be found with the Starter Content. If you have not done so already, make sure that your project includes the Starter Content. This how-to also uses the FX_Smoke emitter created in the tutorial Create a Sprite Smoke Effect in Niagara.
Create System and Emitter
You can create a Niagara system from scratch by right-clicking in the Content Drawer as has been done in previous tutorials. However, if you already have a saved emitter to use as a starting point, it's also possible to duplicate it and start from there.
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Create a new folder for this tutorial in the Content folder for your project.
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Make a copy of the FX_Smoke emitter you created in Create a Sprite Particle Effect in Niagara.
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Drag this duplicate emitter to the folder you created in step 1. In the popup context menu, select Move.
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Rename the copied emitter FX_DarkSmoke. This distinguishes it from the smoke effect created in the Create a Sprite Smoke Effect in Niagara tutorial.
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Right-click on your new smoke emitter, and select Create Niagara System.
There are multiple ways to create new Niagara systems. Because you are starting with an emitter you have already created, the method used here quickly creates a system containing that emitter.
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Name the system DarkSmoke. This is to distinguish it from the smoke effect created in the Create a Sprite Smoke Effect in Niagara tutorial.
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Drag the DarkSmoke system from the Content Drawer into your Level, so you can preview the changes in the context of your project's world.
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When you make a particle effect, it is always a good idea to drag your system into your Level. This gives you a chance to see every change and edit in context. Any changes you make to the system automatically propagate to the instance of the system in your Level.
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Double-click the FX_DarkSmoke emitter to open it in the Niagara Editor. After you have edited the settings in the emitter, you will need to save the DarkSmoke system also.
Edit the Emitter Update Settings
First you will edit the modules in the Emitter Update group. These are behaviors that apply to the emitter itself, and that update each frame.
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In the System Overview, click the Emitter Update group to open it in the Selection panel.
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Expand the Emitter State module. This module controls time and scalability for this emitter. Because you used the Simple Sprite Burst template, the Life Cycle Mode is set to Self.
Normally this is used for complete customization of emitter life cycle logic for this specific emitter, but it is not needed for this effect. Click the dropdown and set the Life Cycle Mode to System. This enables your system to calculate life cycle settings, which usually optimizes performance. By default, the system loops infinitely on a 5 second interval.
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Open the Spawn Rate module. Set the Spawn Rate to 25.
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Edit the Particle Spawn Settings
Next, you will edit the modules in the Particle Spawn group. These are behaviors that apply to particles when they first spawn.
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In the System Overview, click the Particle Spawn group to open it in the Selection panel.
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Open the Initialize Particle module. Under Point Attributes, expand Lifetime. The Lifetime parameter determines how long particles will display before they disappear. Change the Lifetime Mode, Minimum and Maximum values to the following.
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Parameter Value Lifetime Mode Random Minimum 3.0 Maximum 5.0 -
Expand Color. You can set the smoke to a single color, or change the Color Mode to Random Range to get some variability in the color of each particle. Change the RGB values to the following:
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Color Minimum Maximum Red 0.5 0.205 Green 0.5 0.205 Blue 0.5 0.205 -
Under Sprite Attributes, expand Sprite Size. Make sure Sprite Size Mode is set to Random Uniform, which gives minimum and maximum values. New particles will be created at a random size between these values. Change the Minimum and Maximum values to the following:
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Parameter Value Minimum 50 Maximum 90 -
Open the Add Velocity module. In the previous tutorial, we had set the Velocity to Random Range Vector. This adds Minimum and Maximum values. Each new particle that is created has a random value between these two ranges set for its initial velocity. Change the Velocity Minimum and Maximum values to the following:
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Value Minimum Maximum X 12 32 Y 0 0 Z 5 7 -
Open the Sphere Location module. New particles are generated within the sphere when they are first created. Change the Sphere Radius value to 30.
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Edit the Particle Update Settings
Now you will edit the modules in the Particle Update group. These behaviors apply to an emitter's particles and update each frame.
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In the System Overview, click the Particle Update group to open it in the Selection panel.
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Open the Acceleration Force module. Set the Acceleration Z value to 20.
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Open the Scale Color module. Make sure the Scale Mode is set to RGB and Alpha Separately. You only want to adjust the alpha values so that the color fades in and then pulses out as the particle ages. Scale Alpha should be set to Float from Curve. Click on the Pulse template in the curve editor to quickly apply this shape to the curve.
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End Result
After following these steps, the Smoke system in your level will produce a smoke effect similar to the one in the image below.
