Create a Low-Overhead Mobile Project

Most new Unreal Engine (UE) projects provide a large array of powerful rendering features out of the box with the expectation that teams will optimize their projects by removing or disabling features that are not necessary.

Mobile and Automotive HMI projects require high efficiency to make the most of their hardware and provide users the most responsive possible experience. Therefore, the most productive workflow for this type of project is to start with as minimalistic a feature set as possible and carefully choose the features you want to include.

This guide provides instructions for how to set up a template project with minimalist specs, stripping UE to the leanest overhead for highly performance-oriented new projects.

Create Your Project

To set up your project, we recommend the following guides: 

• Android Quick Start for Android and HMI developers.

• iOS Quick Start Guide for iOS, tvOS, and iPadOS developers.

This ensures that you set up all the components you need to support a mobile project and package on your device.

Disable Plugins

By default, UE has a large suite of plugins enabled so that users can explore a wide range of tools and platforms. This section provides instructions on how to remove all plugins that will not impact a mobile project.

To disable unnecessary plugins, follow these steps:

1. Locate your project's directory on your computer. Your .uproject file is located in your project's root folder.

   

2. Right-click your .uproject file to edit it in a text editor.

3. In the Plugins section of your .uproject file, copy and paste the following text:

   Console Output

   "Plugins": [
   		{
   			"Name": "SteamVR",
   			"Enabled": false
   		},
   		{
   			"Name": "MagicLeapMedia",
   			"Enabled": false
   		},
   		{
   
   Expand codeCopy full snippet(178 lines long)

   You can re-enable any plugins that you need in the Plugins manager later.

4. If you are using a C++ project, right-click your .uproject file and click Generate Project Files to regenerate your IDE's project files.

   

5. Relaunch Unreal Editor and load your project.

Set Your Project to Low Scalability Settings

Scalability settings are presets for groups of settings, such as shadows, lighting, and texture quality. Each setting takes multiple config variables and condenses them into buckets for Low, Medium, High, Epic, and Cinematic quality levels. Low represents the settings scaled down to their absolute minimum, while Epic represents the highest setting you'd use for a realtime application.

UE typically sets new projects' scalability settings to Epic to ensure the best possible visuals when you import new art assets. This section provides instructions on how to quickly set all scalability settings to Low so that you can build up your feature set starting from the most low-overhead project possible.

To adjust Scalability Settings, follow these steps:

1. Open your project in Unreal Editor.

2. Click the Settings button in the main toolbar.

3. Highlight the Engine Scalability Settings sub-menu. Click Low to set every scalability group to the lowest possible setting.

   

Changing scalability settings in the Editor does not affect final builds. Unreal Engine uses configuration files (.ini) to set values that load upon startup. Scalability settings are defined in Engine/Config/BaseScalability.ini and platform-specific config files (such as Engine/Config/Android/AndroidScalability.ini).

Config files take precedence over each other in the following order:

For information about how you can set values on a per-device basis and within device profiles, see Customizing Device Profiles and Scalability for Android.

You can learn more about scalability settings in Introduction to Performance Profiling and Configuration and the Scalability Reference.  

Set Your Preview Platform

Your Preview Platform is the target platform that you want Unreal Editor to imitate in its viewports. The in-editor preview platform is an approximation of what your application will look like on a target platform. It is important that you test on the actual device, the Android emulator in Android Studio, or the iOS emulator in Xcode for more accurate testing. However, the preview platform will give you the quickest idea of what your visuals should look like directly from the editor.

To set your Preview Platform, follow these steps:

1. Click the Settings button in the editor's main toolbar.

2. Highlight the Preview Platform sub-menu.

3. Select the platform that you want the editor to emulate.

   

Unreal Editor will take some time to re-compile shaders for the new platform, but once it's done, your visuals should reflect the device profile for the selected preview platform. You can also load a .json file from your test device to get an even more fine-tuned preview with that device's specific device profile and settings.

For more information about setting up your Preview Platform, see the Mobile Previewer documentation.

For Android and HMI developers, UE supports Vulkan rendering feature levels. See the Android Vulkan Mobile Renderer page for more information about Vulkan compatibility in UE.  

Further Reading

Now that you have reduced the overhead in your project, this is a great opportunity to test out different settings and see their impact on your application's fidelity and performance.

For an introductory overview of performance profiling, see Introduction to Performance Profiling and Configuration. We recommend setting yourself up to profile your application with Stat Commands at a minimum, but ideally you should also be prepared to use Unreal Insights and RenderDoc.

Once you've got those resources set up, see Configuring Graphics Performance on Mobile for an overview of mobile-specific performance considerations and scalability tools.