Build and preview custom IES profiles.
IES Master Studio lets lighting artists and technical artists combine layered parameters into custom IES distributions, inspect the result through analytic and real-time previews, export an .ies file, import it as a Texture Light Profile and apply it to supported selected lights.
Layered authoring, shaping and preview
Blend modes
Layers can use Add, Subtract, Multiply, Max or Overlay. Layer order matters because the first layer acts as the base and later layers combine with it.
Built-in presets
Default, Spotlight, Flood, Wall Washer, Double Beam and Candle are available as starting points. Presets can also be saved and loaded as JSON.
Preview recomputation
Parameter changes trigger preview recomputation across the analytic and real-time views.
- Polar preview uses 721 samples from −180° to +180° at 0.5° steps.
- Top view uses 360 samples, one per degree.
- Side view uses point-cloud sampling with 180 horizontal slices and 2° vertical steps, filtered by intensity threshold.
- The 3D preview rebuilds IES content and regenerates a transient Texture Light Profile.
Keep layer count moderate and avoid extreme Noise values when you need smoother UI interaction.
Install and open IES Master Studio
- Install the plugin from Fab into the Unreal Engine project or Engine plugins folder.
- Launch the project in Unreal Editor.
- Open Edit > Plugins.
- Find IES Master Studio and enable it.
- Restart the editor when prompted.
Open the tool from Window > IES Master Studio.
From a new layer to an imported profile
1Open the tool
Confirm the Layers list, analytic previews and Inspector are visible.
2Create and manage layers
Use + Add Layer to create a layer. Select a layer to edit it, reorder it with the per-layer controls or remove it.

3Choose a blend mode
Select how the active layer combines with the layers below it. The available modes are Add, Subtract, Multiply, Max and Overlay.
4Shape the distribution
Use Power, Beam Angle, # Beams, Softness, Beam Offset and Edge Ease to define spread, split beams and edge response.

5Add asymmetry and procedural detail
Asymmetry Strength introduces directional bias. Noise, Seed and Frequency add procedural variation.
6Validate with analytic previews
Use Polar for vertical distribution, Top View for horizontal variation and Side View for the point-cloud representation. The Side View can be rotated with left-mouse drag.

7Validate in the real-time 3D preview
The preview uses a Spot Light, simple geometry and volumetric fog.
- Shift + Arrows / PageUp / PageDown: move the preview light.
- Alt + Arrows / PageUp / PageDown: move the target sphere.
- Ctrl + Arrows / PageUp / PageDown: adjust preview material intensity scaling.
8Use or save presets
Select a built-in preset to populate starting values, or use Save Preset / Load Preset for JSON presets.
9Export and import
Set File Name and choose EXPORT .IES. The file is written to Project/Saved/IESExports/<FileName>.ies and imported to /Game/IESProfiles/<FileName> as a Texture Light Profile.
10Apply to selected lights
Select actors in the level and choose APPLY TO SELECTED LIGHTS. The last imported profile is assigned to Point Light and Spot Light components on the selected actors and Use IES Brightness is enabled.
How the system evaluates profiles
Layer blending behavior
A global normalization maximum is computed by sampling combined intensities across 16 horizontal planes and 181 vertical angles. Multiply and Overlay use this maximum to keep output stable across different lumen values.
Asymmetry implementation
Asymmetry shifts the evaluated vertical angle with a sinusoidal function of horizontal angle scaled by Asymmetry Strength. This supports directional distributions such as wall-wash style beams.
Preview versus exported behavior
The 3D preview creates a transient Texture Light Profile in memory and assigns it to the preview Spot Light. Preview brightness is driven by the sum of layer lumens. When the profile is applied to level lights, Use IES Brightness is enabled.
Current constraints
- Apply targets Point Light and Spot Light components. Rect Light, Directional Light and other light types are not handled.
- Imported assets use the fixed destination /Game/IESProfiles.
- Imported assets are not auto-saved and should be saved manually when persistence is required.
- Undo / Redo is not guaranteed for Apply operations.
- JSON presets expect specific fields; missing fields can prevent loading.