Developing mobile applications on a modern engine opens up enormous opportunities for indie developers and large studios. Unreal Engine has long ceased to be a tool exclusively for PCs and consoles, offering advanced graphics even on smartphone screens. However, the path from an idea to a working one APK file may seem like a confusing labyrinth of settings and dependencies to a beginner.
Why should you choose this particular engine for mobile development? It's about the system Blueprints, which allows you to create complex logic without writing lines of code, and a powerful renderer. But in order for your project to run successfully on a device with Android, you must strictly comply with the requirements for the environment and project configuration. In this article we will look at the key stages of preparation and assembly.
It is important to understand that mobile development imposes specific restrictions on resources. If on a PC you are used to using heavy textures in 4K and complex lighting in real time, then on a smartphone such solutions will lead to a drop in frame rate. Therefore, the process of how to make a game on Android begins not with code, but with competent optimization of assets at the design stage.
Preparing the working environment and installing the SDK
The first step is to correctly install the necessary components. The engine itself does not contain all the tools for compilation for mobile platforms by default. You will need to install Android Studiowhich will provide access to Android SDK i Java Development Kit (JDK). Without these components, the editor simply will not see the connected device or emulator.
After installing the development environment, you need to configure the paths inside the Unreal Engine itself. This is a critical step, as incorrect paths will result in compilation errors. Go to menu Edit → Project Settings → Platforms → Android. Here you will see fields for specifying the paths to the SDK, NDK and JDK.
⚠️ Attention: Versions NDK and JDK must strictly correspond to the versions supported by your current version of Unreal Engine. Using incompatible versions (for example, a too new JDK with an old engine) will cause fatal build errors.
Also make sure that you have the necessary platforms installed inside the Android SDK Manager. Usually you need Android SDK Platform-tools and a specific version of the API that you plan to use as the target. For modern games, the current standard is API level 30 and higher, which ensures compatibility with new versions of the operating system.
Use Windows environment variables for paths to the SDK if they contain spaces or Cyrillic - this will prevent many compilation errors.
Setting up a project for a mobile platform
After setup environment, we move on to the configuration of the project itself. By default, Unreal Engine creates a PC project, so you need to switch the target platform. In the project window, find the section Project Settings and go to the tab Platforms. Here you need to activate the checkbox opposite Android.
Particular attention should be paid to the graphics settings. Mobile devices use different rendering APIs than desktops. In the Project Settings → Rendering section, select the target API. For most modern devices, the optimal choice would be Vulkan or OpenGL ES 3.2. The choice depends on the specific audience and supported devices.
- 📱 Minimum Android version: Set to at least 7.0 (API 24) to cover most active devices but avoid problems with outdated drivers.
- 🎨 Texture format: Select ASTC for the best balance quality and size, or ETC2 for maximum compatibility with older chipsets.
- 📐 Screen orientation: Determine whether the game will be portrait or landscape, and fix this in the settings so that the interface does not "float".
Don't forget to check your control settings. On a PC, you use a keyboard and mouse, whereas on a smartphone, the main input tool is the touch screen. You will need to configure Virtual Joystick or touch zones in the interface. This is done through the system Input in the project settings, where actions are mapped to virtual buttons.
Optimizing graphics and performance
Creating a game on Android requires strict discipline regarding polygons and textures. What looks great on a monitor with a high-end graphics card can turn into a slideshow on a mobile processor. The key tool here is the LOD system RTX 4090, can turn into a slideshow on a mobile processor. The key tool here is the LOD system. LOD (Level of Detail).
Automatic LOD generation in Unreal Engine works quite well, but mobile projects often require manual tuning. Make sure that the outermost levels of detail contain the minimum number of polygons. It is also critical to use texture atlases to reduce the number of draw calls (Draw Calls).
| Optimization parameter | Recommended value | Impact on FPS |
|---|---|---|
| Shadow resolution | 512x512 or 256x256 | High |
| Post Processing | Disable or Low | Average |
| Number of light sources | Maximum 1 dynamic | Critical |
| Smoothing (Anti-Aliasing) | FXAA or Mobile MSAA 2x | Average |
Using baked lighting (Baked Lighting) instead of dynamic lighting can significantly relieve the processor and video card of the smartphone. Light and shadows are calculated in advance and stored in textures, which gives a stable frame rate even on budget devices. To configure this process, use the tool Build → Build Lighting Only.
The Secret of Mobile Optimization
Disable real-time reflections (Screen Space Reflections) in the post-processing settings. On small smartphone screens, players rarely notice their absence, and the performance increase can reach 10-15%.
Working with touch controls and interface
The interface of a mobile game is radically different from the desktop one. Controls should be large, easy to press with a finger, and not block important elements of the game world. The system UMG (Unreal Motion Graphics) allows you to create adaptive interfaces, but requires the correct setting of anchors (Anchors).
When creating buttons and joysticks, take into account the “dead zones” at the edges of the screen, where it is inconvenient for your fingers to reach. The control logic must handle multi-touch, since players often use several fingers simultaneously to move and shoot. Set up events Touch Started, Touch Moved and Touch Ended in the blueprints column.
⚠️ Attention: Be sure to test the interface on real devices with different screen diagonals. The emulator does not always correctly convey the proportions and pixel density, which is why the buttons may be too small or move off the edge of the screen.
For ease of control debugging, you can enable the display of visual elements only in game mode, hiding them in the editor. This will make working with the level easier. Use widgets to display health, ammo and other critical data, placing them in areas that are not covered by your fingers when playing.
APK compilation and assembly process
When the project is configured and optimized, the moment of truth comes - assembling the build. In Unreal Engine, this process is initiated through the menu File → Package Project → Android. Before starting, make sure that the correct build mode is selected: Development for tests or Shipping for release.
Mode Development allows you to connect a debugger and display logs in real time, which is indispensable when searching for bugs. However, this build is slower and larger in size. The mode Shipping disables all debugging functions, optimizes the code and encrypts assets, making the game ready for publication.
☑️ Ready for assembly
Compilation time directly depends on the power of your PC and complexity of the project. The first assembly can take from 10 minutes to several hours. During the compilation process, the engine packages all assets, compiles shaders for the mobile GPU and links the native code. If the process is interrupted, carefully examine the log file, which is usually located in the folder Saved/Logs.
Testing and debugging on a real device
An emulator is a good tool for quickly checking logic, but it does not replace tests on hardware. Connect your smartphone to your computer via a USB cable, turn on the device mode USB debugging in the developer menu. Unreal Engine should automatically detect the connected device.
To launch the game directly from the editor, use the button Play → Launch On and select your device. This allows you to quickly iterate changes. If the game crashes immediately after launch, first check the logs via Window → Developer Tools → Mobile. The reasons for the crash will be indicated there, often related to the lack of necessary libraries or errors in shaders.
Pay attention to the heating of the device and battery consumption. Mobile games should not turn your smartphone into a stove. Use the built-in profiler Unreal Insights or third-party tools like Android Profiler to analyze the load on the CPU and GPU. Memory optimization is also critical: make sure that the game does not consume more RAM than is available on the target devices.
Always do final testing on mid- and low-end devices. If the game runs smoothly on a budget smartphone, it will fly on flagships.
Frequently asked questions and problem solving
Why can't Unreal Engine see my Android device?
Check whether developer mode and USB debugging are enabled on the phone itself. Make sure that the ADB drivers are installed and the paths to the Android SDK in the project settings are correct. Try restarting the editor after connecting the cable.
How to reduce the size of the final APK file?
Use separation of builds by architecture (ARM64, ARMv7). Disable unused platforms in the project settings. Compress textures to the maximum limit acceptable for quality, and remove unnecessary language packs if they are not needed.
Is it possible to publish a game on Google Play built in Development mode?
No, the app store only accepts builds in the mode Shippingsigned with the correct release key. Development builds contain debugging information and are not optimized, so their use in the public domain is prohibited.
What to do if the game slows down only on certain phone models?
Most likely the problem is with the GPU drivers or overheating. Try lowering the graphics settings for these devices through the Quality Levels system in Unreal Engine. Check the logs for shader errors specific to the Mali or Adreno chipsets.