Using hot reload with Gameface installed as a game plugin

Hot reload via the IDE is only possible with Gameface installed as an engine plugin. Attempts to use hot reload via the IDE (e.g. Visual Studio on Windows) with Gameface installed as a game plugin will fail due to a known bug in UE4 where it tries to hot reload game plugins even though they haven't been modified. Epic are aware of the issue but haven't given any estimates on when a fix can be expected. As an alternative, you can use hot reload via the Unreal Editor when using Gameface as a game plugin.

UE4 on Mac

UE4 is crashing on Mac version 10.12 (Sierra) or lower with integrated video card due to driver bug. Possible solution is to upgrade to newer version of Mac, for example 10.13 (High Sierra).

Unreal Engine 5 early access

Using a source checkout with trial packages

All plugins/games that come with Gameface are prebuilt using Unreal Engine 4. If you want to run them, you will need to "Generate Project Files" from your game's .uproject file and build from the generated solution.

Using a Unreal Engine 5 binary engine

If you are using a binary version of Unreal Engine 5 early access, you will likely hit the following error after installing the plugin:

Expecting to find a type to be declared in a module rules named `CohtmlPlugin` in "UE5Rules"

This happens due to a currently unresolved bug in Unreal Engine 5 Early Access, so using a source checkout is recommended. If you cannot use a source engine, for example due to limitations to your build infrastructure, you can still use a binary engine with the following workaround:

Check out a source engine on the Unreal Engine 5 early access branch.
Add the contents of this commit to your source.
Build the UnrealBuildTool project with this change and use the resulting binary to replace the one in <YourBinaryUE5Root>/Engine/Binaries/DotNET/UnrealBuildTool/.

Missing live views on mobile devices

There is an issue with the live views that causes them to not be rendered on mobile devices (Android and iOS). As a workaround, you can add a black background behind the live view in the html as shown here:

<div id="liveView1" class="layoutStyle98 positionStyle185 leftMask" style="background:black;">
   <img src="TextureRenderTarget2D'/Game/MapAssets/LiveViews/RenderTargetOnPlayer.RenderTargetOnPlayer'"
       class="visualStyle357 layoutStyle99 positionStyle193">
</div>

Incorrect safe zones on mobile devices

Safe zones on Android and iOS platforms are not calculated correctly. Additionally, on some iOS devices, there can be rendering artifacts when safe zones are enabled.

Missing input for in-world views on Android

Input for in-world views requires getting the mesh data from the GPU so the plugin can determine the position of the input event in our Cohtml view. However, this functionality is not supported by UE4's GLES implementation for Android.

To have a working input for in-world views on Android, "Support UV From Hit Results" should be enabled in Physics Settings.

Note: Enabling the setting will increase the size of your apk as UE4 will start storing the UV coordinates for each mesh.

Missing input for in-world views using Vulkan rendering

Input for in-world views requires getting the mesh data from the GPU, but the Vulkan API does not support this yet, so instead the plugin have to access the CPU data if it is available.

To have a working input for in-world views using Vulkan, "Allow CPU Access" option should be enabled in the static mesh settings of the meshes, used for the in-world views.

Asserting input for in-world views using DirectX12 rendering in UE4.23

Input for in-world views requires getting the mesh data from the GPU, but after UE4.23.0 users can hit assert in FD3D12DynamicRHI::LockBuffer using DirectX12.

The issue has already been reported to Epic Games. The fix is expected to be present in the UE4.23.1 release.

This issue can be resolved by reverting the if statement inside the FD3D12ResourceLocation::AsStandAlone function as it was in UE4.22.3.

No sound in video playing on iOS

Playing video on iOS has no sound because UE4 has no implementation for Procedural sounds for this platform.

Slow loading of UI resources over HTTP(S)

The slow loading of UI resources over HTTP(S) is due to the default Unreal Engine settings for HTTP, making the download of files over HTTP(S) very slow. Large resources will be affected the most, such as 4K images and video files.

By adding this to the Engine.ini configuration of your project or engine, you can significantly optimize the download speeds:

[HTTP]
HttpThreadActiveFrameTimeInSeconds=0.00001

[HTTP.Curl]
BufferSize=524288

To find out more about this problem and the suggested Engine.ini changes, you can check this related community conversation.