Hi everyone,
I’m investigating a performance issue related to SceneCapture2D.
I have two completely different SceneCapture2D actors in my project (one is from a plugin and one is my own implementation), and both exhibit the exact same behavior.
The Render Target resolution is only 64x64, yet I get random frame spikes.
The important part is that the cost is not constant. Most frames are fine, but occasionally the SceneCapture causes a large spike.
In Unreal Insights, the spike appears under:
- SceneCapture → RenderScene
- RHIThread Lock Wait (sometimes around 40–50 ms)
Current setup:
- Unreal Engine 5.5.4
- Render Target: 64x64
- Capture Every Frame = Enabled
- Capture on Movement = Enabled
- Always Persist Rendering State = Disabled
- No Lumen
- No Nanite
- No Virtual Shadow Maps (using Cascaded Shadow Maps)
Since two unrelated SceneCaptures behave the same way, I don’t think this is plugin-specific.
Has anyone seen intermittent SceneCapture spikes like this?
I’m particularly interested in knowing whether this could be caused by:
- RHI synchronization or GPU stalls
- SceneCapture2D recreating rendering resources
- Texture streaming
- Shadow rendering
- Some known SceneCapture2D limitation in UE 5.5
Any suggestions on what to profile next would be greatly appreciated.
Thanks!