Hi guys, I am having issues with frame times in my scene.
Its a simple car configurator consisting of a skeletal mesh, some lights and an environment dome.
The scene by default renders at around 20ms. However, when I open the doors and zoom into the cockpit, the scene increases to 80+ms. In the GPU Visualizer, this is mainly increased by the lights. This, however, doesnt make sense to me, as the lights are in the scene, no matter if the car doors are open or not?! First, one of the lights at the front was causing a 18ms increase, I removed it. Now a differnt light is causing a 27ms delay, that previously was at 1.2ms. This seems really weird, doesnt it? Anyone have a clue whats going on?
What makes this even more weird, is that if I hide the Car Blueprint while the “game” is running, the car is still visible, however the render times drops back to 20ms and the performance is perfect.
Someone in a discord forum mentioned that It probably has to do with the interior geometry being more visible when the doors are open and therefore the performance dropping. That doesnt make any sense to me though as the geometry consists of a single mesh, so it’s not like it could cull away parts of the interior when they are not visible. Additionally, I can see the same parts of the car through the windows, as when the doors are open, Invalidating this this idea IMO. The guy from discord suggested to turn the skeletal mesh into a nanite static mesh. This brings a host of problems with it though (no transparency, broken shading etc).
I tried using UnrealInsights, however Im quite overwhelmed and dont exactly know what to look for. In the timing, I can tell that the issue (again) seems to look like the lighting (which is still confusing to me and doesnt quite make sense).
I would appreciate any help I can get here!
Cheers,
-CB
EDIT: I just optimized the car with an internal tool I have from 5mio polygons to 2.5 and the performance is just the same, so that should solidify my assumption that its not a matter of polygons.