Unreal Engine Importer


Unreal Engine 5.2.0 and up. (Windows and macOS)

Additional Requirements:

The material library is compatible with Legacy & Substrate Materials, however we recommend using Legacy Materials.

This is a Step by Step Install Guide, you can access the video guide from this link.


Download the appropriate GreyscalegorillaUnrealImporter.zip file from this link.

Note that there are different versions for both Windows and macOS. And also different versions for Unreal Engine 5.2 and 5.3. So make sure to download the correct version that you need.

Unzip it into the Plugins/ folder in the Engine directory structure. If the Plugins folder does not exist then you should create it.

You should end up with a structure such as below:

  • Engine installation: UE_DIRECTORY/Engine/Plugins/GreyscalegorillaUnrealImporter/[Zip content]
    • Which on Windows for UE 5.3 would be the following:
    • C:\Program Files\Epic Games\UE_5.3\Engine\Plugins\GreyscalegorillaUnrealImporter\

The following shows installing the importer plugin into the Unreal Engine folder.

If you are on Mac go to your main harddrive Users folder then under Shared folder Epic Games directory, find your Unreal version. Open the “engine” folder and then copy into the “Plugins” folder.

(If the Plugins folder does not exist then you should create it.)

If you prefer you can also install the importer plugin directly into a Project.

NOTE: If you install for Engine you just need to enable the plugin for your each project. If you install for Project you need to do the installation for each project so we recommend to install for Engine.

You do NOT need to install into Project if you installed it into the Unreal Engine folder directly as shown above.

Activating the Importer Plugin

Once you have copied the plugin to that above location you should restart your UE project.

  • Now go to Edit→Plugins

From the dialog type in “Greyscalegorilla” and click checkbox to activate the plugin.

You may be asked to restart UE. (restart message pop-up at right bottom of screen)

After restarting, you’ll find the importer plugin icon on the UI and under the Window menu.


From the Unreal Engine menu, select "Window→Import a Greyscalegorilla Material"

Browse for the downloaded materials folder containing the unzipped contents of the zip files that were downloaded from the Product Catalog. and click the “select folder” button.

Note: When unzipping the files you should ensure it is unzipped into a folder, preferably using the same name as the zip file itself.

You can select an individual asset folder, or a parent folder. It will search through all the subfolders looking for the Greyscalegorilla materials.

After selecting a folder you will then be presented with a list of materials found in the folder and all of its subfolders.

You can select one or more and then click Import button. You will see a confirmation message that the import was successful. Click OK.

The textures will be copied to your Content Browser, any imported GSG material will be listed under the Greyscalegorilla folder.

You will see the imported material and its instance in the Unreal Content Browser.

Each material has an Instance which provides a flexible and efficient way to create variations of base material without duplicating the entire material. You can have numerous customized instances.

Some materials expose parameters to let you tweak the material, you can see these on the Material Instances. Patterned Canvas materials is one such example that lets you tweak the colors specified by the puzzlematte.

Now you can assign or drag and drop the material instance to any object in your scene.

IMPORTANT NOTE: Project Settings > Engine > Rendering > Virtual Textures needs to be unchecked before importing GSG materials.

NOTE: Project Settings > Engine > Rendering > Textures "Texture Streaming" needs to be unchecked for best experience.


You can get this message after importing GSG materials:

This is not an error message. Rebuilt refers to performing the calculations necessary to determine how to render light and shadows in realistic manner. Building light requires processing power and some time so it could take from a couple of seconds to a minute depending on your scene.

To perform the calculations and conversions in your project go to top Menu > Build and select Build Lighting Only.

You will see the progress of the build in the lower-right corner of the screen and when it's finished, it will let you know that build is complete. The "Lighting Needs to Be Rebuilt" message will disappear.

Alternative import workflow (only for Unreal Engine)

Within each material folder is a file ending in .gsgm. You can drag and drop this file directly into the Content Browser in the folder of your choosing. Once dropped it will the copy across the textures to that folder and create the material at that location.

Substrate support

Substrate is still considered to be an experimental feature in Unreal Engine.

The plugin works with both Legacy Materials and Substrate Materials.

Note: We recommend using Legacy Materials option in Unreal Engine.

Substrate is not enabled by default for new UE Projects however if you wish you can enable it.

Official documentation at: https://dev.epicgames.com/community/learning/courses/92D/unreal-engine-strata-materials/VXV6/unreal-engine-strata-intro-submitting-feedback

To enable Substrate support:

  1. A .uproject's EngineAssociation needs to be changed to 5.2 (this only needs to be done if you have moved from 5.1 to 5.2).
  2. Substrate needs to be turned on in Project Settings.
    1. Go to Edit→Project Settings
    2. Type in “Substrate” at the top search bar
    3. Enable “Substrate materials (Experimental)

Notes for macOS users

Unreal on macOS requires installation of Apple XCode for Metal shaders compiler.

You can download and install XCode from the Apple AppStore.

However after installation when you run Unreal sometimes it cannot find it and the message below may appear.

In this case run the Terminal and paste the code below and hit Enter, then type your password hit Enter:

sudo xcode-select -s /Applications/Xcode.app/Contents/Developer

Now you can run Unreal without any issues.

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