UE 4.19.2 - Render Textures costing way too much but only in packaged game

Development Rendering
1

Hello, I have a game using a RenderTexture to show a 2D screen in front of a VR player.

It is working fine in VR Preview but use a lot of frame time when started as a packaged project. I did a minimal implementation both in 4.18.2 and 4.19.2 and the issue does not happen in 4.18!

the 1024x1024 RT is captured every frame (at 90fps for VR) and it run smoothly in 4.18 (draw time being between 2-3ms) but when I test the same project in 4.19, the draw time vary between 3 and 9ms wich is not usable.

In a more complex scene, I’ve got a constant 11ms in VR Preview and something like 150 ms when packaged. This did not happen in 4.18.

I think it might be a bug with the implementation of the new ScreenPercentage/PixelDensity regarding RenderTextures but I’m not sure.

Does anyone has any hindsight on the subject? I don’t want to port my game from 4.19 to 4.18…

Thank you!

2

https://forums.unrealengine.com/unreal-engine/feedback-for-epic/1457519-4-19-0-editor-hangs-hiccups-constantly/

Read up in there. There is some kind of regression involving a few different systems. Render targets, mesh particles, billboard components, and more.

3

I’d join IronicParadox in inviting you to the thread linked above and encourage to submit a bug report. This is a critical regression in the engine.