Hey all, I have a Stationary Skylight and an Unlit Sky Sphere mesh that isn’t casting shadows in a scene together, along with a basic platform, wall planes and mesh decals.
When I capture reflections in-Editor and build the lighting, the reflections seem accurate to the scene. When I simulate or play the level however, the scene capture of anything without an Unlit material becomes dimmer.
The Skylight is set to use SLS Capture Scene with a Sky Distance Threshold reduced down to 1. ‘Lower Hemisphere is Solid Color’ has been un-ticked. Beyond that, no other settings have been changed on it.
I’m attempting to use real-world light intensities, the Unlit material of the Sky Sphere has been brightened considerably to match.
Auto-Exposure and Screen-Space Relfections have been disabled, and ‘Extend default luminance range in Auto Exposure Settings’ has been enabled.
Does anyone know what causes this difference? Thanks!
As an update, I’ve also tested a similar scenario in UE 4.27 and am hitting similar issues. The reflection looks accurate in-editor, but the reflection drops to black when simulating or playing the level.
Tested with a different HDRI map, EV100 set to 12 (both min and max) with auto-exposure disabled just to be doubly-sure, same Skylight settings as the first post, no screen-space reflections, no ray-tracing.
I’ve realised the Scene Color buffer is getting absolutely blown out by the sky sphere, as is the Unlit view mode. The Physical Lighting Units page on UE4 docs mentions black patches in reflections possibly being tied to the SceneColor buffer overflowing, and suggests enabling “Apply Pre-Exposure before writing to the scene color” in the Project Settings to counteract this, however this setting was already enabled and disabling this makes no visible difference.
The other solution the page offers is to turn down the brightness of the lights (in this case, the material brightness of the HDRI map), but then the sky is pitch black before the SceneColor buffer looks reasonable.
