Missing PostRender/HUD visualization

[dandar28]

While working on an integration feature involving visualization of 3d helpers, I noticed that 3d helpers were not displayed when launching project from Disguise, while they are correctly displayed when launching UE project alone.

Here the some debug/dev notes:

After debugging this I found what caused this: It's due to something missing from URenderStreamViewportClient implementation with respect to UGameViewportClient in the drawing method: the stuff for drawing post render hud is missing from the renderstream implementation.

I already found the involved piece of code that is missing, which could be found in UGameViewportClient here : https://github.com/EpicGames/UnrealEngine/blob/release/Engine/Source/Runtime/Engine/Private/GameViewportClient.cpp#L1795-L1815

While it is missing from URenderStreamViewportClient and could be placed between these lines: https://github.com/disguise-one/RenderStream-UE/blob/r1.29_UE4.27/Source/RenderStream/Private/RenderStreamViewportClient.cpp#L485-L486

I already found a fix and will be providing a Pull Request asap.