This guide teaches you how to make a flickering light in Unreal Engine 4 using simple Blueprints, materials, and built-in tools. You’ll create realistic, customizable flickers ideal for horror games or moody environments.
Key Takeaways
- Use Blueprints for control: Unreal Engine’s Blueprint system lets you create dynamic flickering without coding.
- Leverage Timeline nodes: Timelines allow smooth, looping flicker patterns with precise timing.
- Adjust light intensity and color: Flickering isn’t just about brightness—color shifts add realism.
- Optimize for performance: Use efficient methods to avoid frame rate drops in complex scenes.
- Customize flicker patterns: Randomize timing and intensity for natural, unpredictable effects.
- Test in different lighting conditions: See how your flicker behaves in dark vs. lit environments.
- Combine with sound and particles: Enhance immersion by syncing flicker with audio or visual effects.
Introduction: Why Flickering Lights Matter in Game Design
Flickering lights aren’t just for horror games—they’re a powerful tool for building atmosphere, signaling danger, or adding realism to abandoned buildings, power outages, or malfunctioning tech. Whether you’re crafting a creepy basement scene or a sci-fi spaceship with failing systems, a well-made flickering light can instantly elevate your game’s mood.
In this guide, you’ll learn how to make a flickering light in Unreal Engine 4 using practical, beginner-friendly methods. We’ll cover Blueprint scripting, material effects, and optimization tips—all without needing to write a single line of C++ code. By the end, you’ll be able to create dynamic, customizable flickering lights that respond to gameplay or run autonomously.
Unreal Engine 4 makes this surprisingly easy thanks to its visual scripting system, Blueprint. You’ll use nodes like Timeline, Random Float, and Set Intensity to control your lights. Plus, we’ll show you how to tweak timing, add randomness, and even sync your flicker with sound effects for maximum impact.
What You’ll Need Before Starting
Before diving in, make sure you have the following:
Visual guide about How to Make a Flickering Light in Unreal Engine 4
Image source: ue-cdn.artstation.com
- Unreal Engine 4.27 or later: Download it from the Epic Games Launcher. Most flicker techniques work across versions, but newer ones may have slight UI differences.
- A basic level: Open or create a new level with some geometry—like a room or corridor—so you can see the lighting effects clearly.
- A light actor: We’ll use a Point Light, but Spot Lights and Rect Lights work too.
- Basic Blueprint knowledge: You should know how to create a Blueprint class and add components. If not, don’t worry—we’ll walk you through it step by step.
No advanced math or programming skills are required. This guide is designed for beginners and intermediate users alike.
Step 1: Setting Up Your Light Actor
The first step is placing a light in your scene. Here’s how:
Place a Point Light in Your Level
Go to the Modes panel (top-left), select the Lights tab, and drag a Point Light into your level. Position it where you want the flicker—like a ceiling lamp or wall sconce.
Adjust Basic Light Settings
With the light selected, open the Details panel. Set the following:
- Intensity: Start with 500–1000 lumens. This gives a good base brightness.
- Attenuation Radius: Set to 1000–2000 units so the light covers a decent area.
- Light Color: Use a warm white (RGB ~255, 240, 200) for realism, or go blue for a cold, eerie feel.
Don’t worry about making it perfect yet—we’ll animate these values next.
Step 2: Creating a Blueprint for the Flickering Light
Now we’ll turn this static light into a dynamic, flickering one using a Blueprint.
Create a New Blueprint Class
In the Content Browser, right-click and select Blueprint Class. Choose Actor as the parent class. Name it BP_FlickeringLight.
Add a Point Light Component
Open the new Blueprint. In the Components panel, click Add Component and choose Point Light. Name it FlickerLight.
Set Default Light Properties
Select the FlickerLight component and set its default Intensity to 800 and Attenuation Radius to 1500. These will be our starting values before the flicker begins.
Compile and Save
Click Compile and then Save. Now you’re ready to add the flickering logic.
Step 3: Adding the Flicker Logic with Blueprint Nodes
This is where the magic happens. We’ll use a combination of Timeline and Random Float nodes to create a natural flicker.
Open the Event Graph
In your Blueprint, go to the Event Graph tab. This is where we’ll write the logic.
Add a Timeline Node
Right-click in the graph and search for Timeline. Add one. This will control the flicker timing.
Set Up the Timeline Curve
Double-click the Timeline node to open its settings. Click Add Float Track and name it FlickerCurve.
Now, add keyframes to simulate flicker:
- At time 0.0, set value to 1.0 (full brightness).
- At time 0.1, set value to 0.3 (dim).
- At time 0.2, set value to 0.9.
- At time 0.3, set value to 0.2.
- At time 0.4, set value to 1.0.
This creates a quick on-off-on pattern. You can adjust the values and timing to make it faster, slower, or more erratic.
Loop the Timeline
Back in the Event Graph, connect the Timeline’s Update pin to a Set Intensity node for your light. Drag from the FlickerLight component and choose Set Intensity.
Multiply the Timeline’s output (the Float Track) by your base intensity (e.g., 800) to scale the flicker. Then wire that into the Intensity input.
Start the Timeline on Begin Play
Drag from the Event BeginPlay node and connect it to the Timeline’s Play pin. This ensures the flicker starts when the level loads.
Compile and Test
Click Compile and go back to your level. Drag your BP_FlickeringLight into the scene and press Play. You should see the light flicker in a repeating pattern.
Step 4: Adding Randomness for Realistic Flickering
A looping timeline creates a predictable flicker. To make it feel more natural, we’ll add randomness.
Use a Timer to Trigger Random Flickers
In the Event Graph, right-click and add a Set Timer by Function Name node. Connect it to Event BeginPlay.
Create a Custom Function
Click the + next to Functions in the My Blueprint panel. Name it FlickerRandom.
Inside this function, add a Random Float in Range node. Set the range from 0.1 to 0.5 seconds. This will be the delay before the next flicker.
Trigger a Quick Intensity Drop
Use a Set Intensity node to drop the light to 200 for a short time (e.g., 0.1 seconds), then return it to 800.
To do this, use a Delay node after setting low intensity, then set it back to high.
Restart the Timer
At the end of the FlickerRandom function, call Set Timer by Function Name again to loop the process.
Now your light will flicker at random intervals, making it feel more organic and less robotic.
Step 5: Enhancing the Effect with Color and Flicker Intensity
Great flickering isn’t just about brightness. Adding subtle color shifts can make the effect more immersive.
Modify Light Color Dynamically
In your Blueprint, add a Set Light Color node. Use a Random Color from HSV node to generate slight variations.
Set Hue to a narrow range (e.g., 30–50 for warm yellows), Saturation to 0.8–1.0, and Value to 0.7–1.0. This keeps the color realistic while adding variation.
Combine with Intensity Flicker
Trigger the color change at the same time as the intensity drop. Use the same timer or timeline to sync them.
Example: Strobe-Like Flicker
For a more dramatic effect, try a rapid on-off pattern with a cool blue tint during the dim phase. This works great for electrical faults or emergency lighting.
Step 6: Optimizing Performance
Flickering lights can impact performance if not handled carefully—especially with many lights in a scene.
Use Efficient Timers
Avoid using Tick events for flicker logic. Instead, use Timers or Timelines, which are more performance-friendly.
Limit the Number of Active Flickers
If you have 20 flickering lights, consider grouping them or using a single controller Blueprint to manage timing.
Use Light Functions (Optional)
For advanced users, Light Functions can create flicker effects directly in materials, reducing Blueprint overhead. But for most cases, Blueprints are simpler and sufficient.
Step 7: Combining Flicker with Sound and Particles
To boost immersion, sync your flicker with audio and visual effects.
Add a Flicker Sound
Import a short audio file (e.g., a buzz or pop). In your Blueprint, use a Play Sound at Location node triggered during the flicker.
Use a Random Float to vary the volume slightly so it doesn’t sound repetitive.
Spawn Sparks or Dust Particles
Use a Spawn Emitter at Location node to create a brief particle effect when the light flickers. Use a small spark or dust puff asset.
Place the emitter near the light source for realism.
Example: Malfunctioning Fluorescent Light
Combine a slow, erratic flicker with a low hum sound and occasional sparks. This creates a convincing broken light effect.
Troubleshooting Common Issues
Even with careful setup, you might run into problems. Here’s how to fix the most common ones.
Flicker Doesn’t Start
- Check that the Timeline or Timer is connected to Event BeginPlay.
- Ensure the Blueprint is placed in the level and not just saved in the Content Browser.
- Verify that the light component is named correctly in the Blueprint.
Flicker Is Too Predictable
- Add more randomness to timing and intensity.
- Use multiple Timeline tracks or nested timers.
- Introduce occasional long pauses (e.g., 2–3 seconds of darkness) for dramatic effect.
Performance Drops
- Avoid using Tick for flicker logic.
- Reduce the number of active flicker Blueprints.
- Use lower-resolution particle effects.
Light Doesn’t Return to Full Brightness
- Check that your Set Intensity nodes are correctly wired.
- Ensure no other Blueprint or level script is overriding the light’s properties.
Advanced Tips for Pro-Level Flickering
Once you’ve mastered the basics, try these advanced techniques:
Use Material Parameters for Flicker
Create a material with an emissive channel controlled by a scalar parameter. Use a Blueprint to animate that parameter over time. This works well for neon signs or screens.
Trigger Flicker Based on Game Events
Make the light flicker when a player enters a zone, takes damage, or interacts with an object. Use collision triggers or custom events.
Create a “Dying Light” Effect
Gradually reduce the base intensity over time, with increasing flicker frequency, to simulate a light about to burn out.
Use Niagara for Dynamic Flicker Particles
For high-end visuals, use Niagara particle systems that react to the light’s intensity. For example, sparks that grow brighter as the light flickers.
Conclusion: Master the Art of Flickering Lights
You’ve now learned how to make a flickering light in Unreal Engine 4 using Blueprints, timelines, and creative effects. From simple on-off patterns to randomized, multi-sensory experiences, you have the tools to bring any scene to life.
Remember, the best flickering lights feel natural and serve the story. Use them to build tension, signal danger, or add realism. Experiment with timing, color, and sound to find the perfect balance for your game.
Don’t stop here—combine flicker with other effects like fog, shadows, or camera shakes to create unforgettable moments. And always test in different lighting conditions to ensure your effect works in all scenarios.
With practice, you’ll be able to create flickering lights that don’t just look good—they feel alive.