I added a new level to use as a title screen and added an actor and terrain. The only screens on this level are in the level BP to rotate the main actor using a timeline and and rotate actor. The problem I am having is shortly after starting the game, the FPS starts dropping from around 50 to 10 FPS over 30 seconds or so. Could the rotate using a timeline be loading up the memory? I ran resmon while it was running and the available memory ran down to 0. Thoughts?
This problem seems to be getting worse with little changes. Now materials that have emissive properties are giving off a “halo” or foggy effect and the shadows all over are almost in an 8 bit resolution. I deleted the new level I added and rebuilt lighting but nothing appears to have fixed it.
Well as far as the FPS issue, I narrowed it down to a timeline running a rotate actor. I deleted it and recreated it and the FPS went back to 80-90. Not sure why the original timeline was causing an issue. I also changed the materials creating the halo effects and reapplied them and they went away. The same with the shadows, I deleted the lights and recreated them and they stopped. It seemed that the whole project had something happen with the files.
If you are rotating terrain, it may be that terrain is just slow to rotate and not intended for that. Can you replace the terrain with a regular mesh? Also just dynamically shadowing a landscape with 1 light can be slow, using multiple shadow casting lights will be even slower.
I only had the timeline rotating a small object in the scene. The shadows became much better once I recreated the lighting. At full screen, I am getting 30-35 FPS now.
Have you tried using the UE4 profiler?
(There are links to other profilers in my signature)