How to Build Lighting in Unreal Engine 4

This guide walks you through building professional-quality lighting in Unreal Engine 4, covering static, stationary, and movable lights, lightmap settings, and performance optimization. Perfect for game developers and virtual environment creators in 2026.

Key Takeaways

• Understand light types: Learn the differences between static, stationary, and movable lights and when to use each for optimal performance and visual quality.
• Master lightmap resolution: Properly configure lightmap density to avoid artifacts and reduce build times while maintaining crisp shadows.
• Use Lightmass settings effectively: Adjust global illumination and shadow quality in Lightmass to balance realism and performance.
• Optimize with lighting scenarios: Create multiple lighting builds for day/night cycles or different gameplay areas without rebuilding everything.
• Leverage real-time ray tracing (if available): Use hardware-accelerated ray tracing in UE4.26+ for photorealistic reflections and shadows on supported GPUs.
• Debug lighting issues: Use visualization tools like Light Complexity and Shadow Density to identify and fix common lighting problems.
• Follow best practices: Keep your scene organized, use emissive materials wisely, and test lighting early and often during development.

Introduction: Why Lighting Matters in Unreal Engine 4

Lighting is one of the most powerful tools in your Unreal Engine 4 (UE4) toolkit. It sets the mood, guides player attention, enhances realism, and can even improve performance when used correctly. Whether you’re building a dark horror corridor, a sun-drenched open world, or a futuristic sci-fi station, mastering lighting is essential for creating immersive experiences in 2026.

In this comprehensive guide, you’ll learn how to build lighting in Unreal Engine 4 from the ground up. We’ll cover everything from basic light placement to advanced techniques like lightmap optimization, global illumination, and real-time ray tracing. By the end, you’ll be able to create visually stunning and performance-efficient lighting setups for any project—whether you’re working on a small indie game or a large-scale virtual environment.

This guide assumes you have a basic understanding of the Unreal Editor interface and have a level open with some geometry. If you’re new to UE4, consider starting with a simple room or outdoor scene to practice. Let’s dive in!

Step 1: Understanding Light Types in Unreal Engine 4

Before placing any lights, it’s crucial to understand the three main light types in UE4: Static, Stationary, and Movable. Each has unique properties and performance implications.

Static Lights

Static lights are baked into lightmaps during the build process. They don’t move or change during gameplay, making them extremely efficient. Use them for environmental lighting like sunlight through windows or fixed ceiling lights.

• Pros: Very low runtime cost, high visual quality when baked properly.
• Cons: Cannot change color, intensity, or position at runtime. Requires rebuilding lighting when modified.

Stationary Lights

Stationary lights are a hybrid. They can change color and intensity during gameplay but cannot move. Their shadows are partially baked and partially dynamic, offering a good balance between performance and flexibility.

• Pros: Can animate brightness or color (e.g., flickering lights), better performance than fully dynamic lights.
• Cons: Slightly higher cost than static lights. Still requires lightmap baking.

Movable Lights

Movable lights are fully dynamic. They can move, change color, intensity, and direction at runtime. Use them for moving vehicles, flashlights, or any light source that needs to animate freely.

• Pros: Full runtime control, no baking required.
• Cons: Highest performance cost. Can cause frame rate drops if overused.

Pro Tip: Use static lights whenever possible. Reserve movable lights for essential dynamic effects. Stationary lights are ideal for lights that need to flicker or dim but stay in place.

Step 2: Placing and Configuring Lights

Now that you know the types, let’s place some lights in your scene.

Adding a Light Actor

1. In the Modes panel (top-left), go to the Place tab.
2. Search for “Light” and drag a Point Light, Spot Light, or Directional Light into your level.
3. Position it where you want illumination (e.g., above a table for a point light, outside for sunlight with a directional light).

Adjusting Light Properties

Select your light and open the Details panel (usually on the right). Here’s what to tweak:

• Intensity: Controls brightness. Measured in lumens for point/spot lights, lux for directional lights. Start with 1000–5000 lumens for indoor lights.
• Light Color: Use the color picker to set mood. Warm white (2700K–3000K) for cozy interiors, cool white (5000K–6500K) for offices or outdoors.
• Attenuation Radius: How far the light reaches. Increase for larger areas, but avoid overlapping too many lights.
• Source Radius: Affects shadow softness. Larger values = softer shadows. Set to 5–20 for natural-looking shadows.

Example: For a realistic bedroom lamp, use a point light with 1500 lumens, warm white color, and a source radius of 10. Place it near the lamp model and adjust attenuation to match the lamp shade’s reach.

Using Directional Lights for Sunlight

Directional lights simulate the sun or moon. They shine uniformly across the entire level.

• Set Intensity to 50,000–100,000 lux for daylight.
• Adjust Light Color to match time of day (e.g., golden at sunrise, blue at noon).
• Rotate the light to control sun angle. Use the Rotation tool (press R) to tilt it.

Pro Tip: Enable Atmospheric Fog (in the Viewport > Show > Visualize > Atmospheric Fog) to enhance the realism of sunlight scattering through the air.

Step 3: Configuring Lightmaps and Lightmass

For static and stationary lights, lighting is baked into lightmaps—textures that store precomputed lighting data. Proper lightmap setup is key to avoiding artifacts and long build times.

Setting Lightmap Resolution

Each static mesh has a Lightmap Resolution value (found in the Details panel when selected). This determines how detailed the baked lighting is.

• Start with 64 for small objects (e.g., chairs, lamps).
• Use 128–256 for walls, floors, and large props.
• Avoid going above 512 unless necessary—higher values increase build time and memory usage.

How to Check Lightmap Density:

1. Press Alt + 3 in the viewport to view Lightmap Density.
2. Green = good, yellow = too low, red = too high.
3. Adjust individual mesh resolutions until most areas are green.

Adjusting Lightmass Settings

Lightmass is UE4’s global illumination system. It calculates how light bounces around your scene.

1. Go to Window > World Settings.
2. Expand the Lightmass section.
3. Key settings to adjust:

• Static Lighting Level Scale: Lower values = higher quality (e.g., 2–4). Default is 4. Use 2 for final builds.
• Num Indirect Lighting Bounces: How many times light bounces. Increase from 2 to 4–6 for richer indirect lighting.
• Indirect Lighting Quality: Higher values = smoother gradients. Start at 1, increase to 2–3 for final builds.
• Environment Intensity: Simulates ambient light from the sky. Set to 1.0 for natural outdoor scenes.

Pro Tip: Use Lightmass Importance Volume to focus baking quality on important areas (like a player path). Place it around key zones and set Lightmass Settings > Use Importance Volume to true.

Step 4: Building Lighting

Once your lights and settings are ready, it’s time to build the lighting.

How to Build Lighting

1. Click Build in the toolbar (or press Ctrl+Shift+;).
2. Select Build Lighting Only to save time.
3. Wait for the process to complete. Progress is shown in the bottom-right corner.

Building can take from seconds to hours, depending on scene complexity and settings. Use lower Lightmass quality during development and increase it for final builds.

Lighting Scenarios (Day/Night Cycles)

Need different lighting for day and night? Use Lighting Scenarios to avoid rebuilding everything.

1. Go to Window > Lighting Scenarios.
2. Click + Add Scenario and name it (e.g., “Day”, “Night”).
3. Adjust lights in each scenario (e.g., turn off sunlight at night, add streetlights).
4. Build lighting for each scenario separately.
5. Switch between them in the editor or via Blueprints at runtime.

Example: In a survival game, use a “Day” scenario with bright sunlight and a “Night” scenario with moonlight and flickering campfires. Switch via a timer or player action.

Step 5: Using Real-Time Ray Tracing (Optional)

If you have a compatible NVIDIA RTX GPU and are using UE4.26 or later, you can enable real-time ray tracing for photorealistic lighting.

Enabling Ray Tracing

1. Go to Edit > Project Settings > Rendering.
2. Enable Ray Tracing.
3. Restart the editor.

Using Ray Traced Lights

• Ray Traced Distance Field Shadows: Enable in light properties for sharp, accurate shadows.
• Ray Traced Reflections: Automatically reflect accurate lighting and geometry.
• Global Illumination (RTXGI): Simulates realistic light bounces in real time.

Note: Ray tracing is GPU-intensive. Use it sparingly in performance-critical scenes. Combine with baked lighting for best results.

Step 6: Optimizing Lighting Performance

Great lighting shouldn’t tank your frame rate. Follow these optimization tips.

Reduce Light Overlap

Too many overlapping lights increase draw calls. Use the Light Complexity view mode (Alt+2) to see how many lights affect each pixel. Aim for green (1–2 lights) in most areas.

Use Light Functions and IES Profiles

Light functions let you project textures or patterns onto light (e.g., a window frame). IES profiles simulate real-world light distribution.

• Create a Light Function material and assign it to a light’s Light Function slot.
• Download IES profiles from manufacturer websites (e.g., Philips, GE) for realistic fixtures.

Optimize Emissive Materials

Materials with Emissive Color act as light sources. But they don’t cast dynamic shadows unless using Emissive Lighting in Lightmass.

• Enable Emissive Lighting in Lightmass settings to make emissive materials contribute to baked lighting.
• Use sparingly—too many emissive surfaces can increase build time.

Use Fog and Volumetrics Wisely

Exponential Height Fog and Volumetric Fog enhance atmosphere but cost performance.

• Set Fog Inscattering Color to match your sky.
• Lower Volumetric Fog Albedo to reduce GPU load.
• Use Fog Shadows only when necessary.

Troubleshooting Common Lighting Issues

Even experts run into lighting problems. Here’s how to fix the most common ones.

Lightmap Artifacts (Streaks or Noise)

• Cause: Low lightmap resolution or overlapping UVs.
• Fix: Increase lightmap resolution. Check that static meshes have proper UV channels (UV1 for lightmaps).

Dark or Flat Lighting

• Cause: Insufficient indirect lighting or low Lightmass bounces.
• Fix: Increase Num Indirect Lighting Bounces to 4–6. Add fill lights or increase environment intensity.

Shadows Are Too Hard or Soft

• Cause: Source radius too small or too large.
• Fix: Adjust Source Radius in light properties. Larger = softer shadows.

Lighting Build Takes Too Long

• Cause: High Lightmass quality or large lightmap resolutions.
• Fix: Lower Indirect Lighting Quality during development. Use Lightmass Importance Volume to limit baking area.

Flickering or Flickering Shadows

• Cause: Light overlap or shadow map resolution too low.
• Fix: Reduce overlapping lights. Increase Shadow Map Resolution in Project Settings > Rendering > Shadows.

Conclusion: Mastering Lighting in 2026

Lighting in Unreal Engine 4 is both an art and a science. By understanding light types, mastering lightmaps, and optimizing performance, you can create breathtaking environments that run smoothly on modern hardware. Whether you’re building a game, a virtual tour, or a cinematic experience, great lighting will elevate your project to the next level.

Remember: start simple, test often, and iterate. Use static lighting where possible, leverage Lightmass for realism, and don’t be afraid to experiment with ray tracing if your hardware supports it. With the techniques in this guide, you’re well-equipped to build professional-quality lighting in Unreal Engine 4—no matter what 2026 throws your way.

Now go light up your world!