Hello,
It seems that this issue occurs due to a bug using DX12 (DirectX 12) with “lumen” which is the default “Dynamic Global Illumination Method” (in the the projects DefaultEngine.ini we have DefaultGraphicsRHI=DefaultGraphicsRHI_DX12 and r.DynamicGlobalIlluminationMethod=1). Hence, you need to either change your RHI settings or your dynamic GI method.
Changing RHI settings
You can either make DefaultGraphicsRHI=DefaultGraphicsRHI_DX11 in DefaultEngine.ini (to use Direct X 11 rather than 12) or go to “Edit → Project settings → Platforms → Windows → Default RHI” and select DirectX 11 or Vulkan (I didn’t test it yet) .
See an example below:
[/Script/WindowsTargetPlatform.WindowsTargetSettings]
DefaultGraphicsRHI=DefaultGraphicsRHI_DX11
Changing the Dynamic GI method
You can change the default DynamicGlobalIlluminationMethod to “None” (or any other method) directly in DefaultEngine.ini , i.e " r.DynamicGlobalIlluminationMethod=0", or from “Edit → Project settings → Engine → Rendering-> Global Illumination → Dynamic Global Illumination Method” and select your preferred method (None, lumen, Screen Space, Standalone Ray Traced (Deprecated) ). These methods correspond to 0, 1, 2, 3 respectively.
You can change the default behavior by going to the config folder in your UE5 project then open DefaultEngine.ini. Under [/Script/Engine.RendererSettings], set r.DynamicGlobalIlluminationMethod to 0.
See an example below:
[/Script/Engine.RendererSettings]
r.ReflectionMethod=1
r.GenerateMeshDistanceFields=True
;r.DynamicGlobalIlluminationMethod=1
r.DynamicGlobalIlluminationMethod=0
r.Lumen.TraceMeshSDFs=0
r.Shadow.Virtual.Enable=1
r.Mobile.EnableNoPrecomputedLightingCSMShader=1
Shabayek