Using hot reload with Hummingbird installed as a game plugin

Hot reload via the IDE is only possible with Hummingbird installed as an engine plugin. Attempts to use hot reload via the IDE (e.g. Visual Studio on Windows) with Hummingbird 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 Hummingbird 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).

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). To workaround this you can add a black background behind the live view 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>

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.

Input for in-world views on Android

Input for in-world views requires getting the mesh data from the GPU so that we can determine the position of the input event in our Hummingbird view. However, this functionality is not supported by UE4's GLES implementation for Android. In order for the input for in-world views to work on that platform, you should enable "Support UV From Hit Results" 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.

Video on iOS

Hummingbird playing video on IOS has no sound because UE4 has no implementation for Procedural sounds for this platform.

HTTP map crash on iOS

Loading the HTTPMap on iOS results in a crash in the JavaScript virtual machine that Hummingbird uses on iOS.