I have a project I’ve been working on for several weeks: A large open world terrain with quite a bit of flora, made with modifications to the third-person template. It was working fine until last night. Now whenever I hit the Play or Simulate button my FPS drops to about one frame every 3 seconds. Even the ambient audio stutters along with the visuals. Any ideas what would suddenly cause this? I can’t think of any recent changes I’ve made that would cause such a drastic drop. Other projects still run fine, and this project was playing at about 35 fps before I closed it last night.
I have good hardware, i7-4790k, 32GB RAM, GTX 980. Can load and run the full kite demo with no problems. It’s just something about the terrain in this project which is causing an issue, but for my life I can’t figure out what it is.
You can find this by using console commands.
All of the below are helpful at isolating causes or at least getting you close to a solid theory.
Stat raw
stat initviews
Profilegpu
Isolate your bottleneck and optimize or make changes to code in those areas. Closing other programs,apps and unneeded windows in editor help close blueprints and disable any popup overlays in any programs or background tasks,anything that draws attention from the rendered window can have horrible effects.
Play test iteration and framerate profiling come near the end of the development cycle, not during it. You need to lookout for things like transparency overdraw, over complex materials, exaggerated particle emitters,nonexistent LOD meshes and poor static mesh culling. Having a good idea of the tradeoffs during content creation pipeline will allow you to avoid most problems. Too many concurrent tick events throughout the game can bog you down too.
Post some photos of your project trouble areas they sometimes speak louder than words.
Also the terrain lod,heightmap, base color pass and collision can kill open worlds if not take care of, dynamic shadow casting and all sorts of shadow problems can make the terrain seem over bearing.
How big is this open world terrain?
Actually for really large open worlds, they recommend that you use dynamic lighting because rendering lightmaps for such a large world is too time consuming. I’d link you to the article I read but I can’t for the life of me remember where it was.