Summary A SpotLightComponent with SpotLightComponent.SurroundingsLight() (and a ProjectiveTexture) lights the flat part of my ceiling and the walls, but never the two sloped ceiling surfaces of a converted attic room, at any angle, intensity, attenuation radius or falloff. The lit area stops in a hard straight line exactly where the flat ceiling meets each slope, even though the beam clearly extends past that line. The sloped surfaces are fully present in SceneReconstructionProvider's mesh, and their faces point into the room. So this doesn't look like a scene understanding coverage problem. It looks as if physical space lighting only considers surfaces classified as horizontal ceiling, wall or floor, and skips slanted ones. Steps to reproduce Open a mixed immersive space in a room with a sloped ceiling (a converted attic, or any vaulted ceiling). Add an entity with SpotLightComponent(color: .white, intensity: 40_000, innerAngleInDegrees: 44.5, outerAngleInDegrees: 45, attenuationRadius: 10), SpotLightComponent.SurroundingsLight(), and a SpotLightComponent.ProjectiveTexture carrying a labelled grid texture so the beam's extent is visible. Place it near the floor under the wearer and aim it straight up. Run SceneReconstructionProvider alongside and draw each MeshAnchor as a wireframe (or as a solid material with faceCulling = .back) to confirm the mesh covers the slopes and faces inward. Expected The projected pattern conforms to every surface in the scene understanding mesh inside the cone, including the sloped ceiling, as it does for the flat ceiling and walls. Actual The pattern appears only on the flat ceiling strip and on the walls. Both slopes stay completely dark, with a hard straight cut at the crease. Tilting the light to aim directly at a slope, raising intensity to 200,000, and changing attenuation radius and falloff make no difference. The wireframe shows continuous mesh across the crease and onto the slopes; the back-face-culled solid view shows the slope faces pointing into the room. Screenshots attached: (1) the projected grid stopping at the crease, (2) the reconstruction wireframe covering the slopes, (3) the solid front-faces-only mesh showing the slopes are front-facing. (4) an additional image of the projected grid with both ceiling and walls in view Code let spot = Entity() spot.components.set(SpotLightComponent.SurroundingsLight()) var light = SpotLightComponent(color: .white, intensity: 40_000, innerAngleInDegrees: 44.5, outerAngleInDegrees: 45, attenuationRadius: 10) light.attenuationFalloffExponent = 0.5 spot.components.set(light) spot.components.set(SpotLightComponent.ProjectiveTexture(texture: gridTexture)) spot.look(at: from + SIMD3(0, 1, 0), from: from, upVector: SIMD3(0, 0, -1), relativeTo: nil) root.addChild(spot) Questions Is physical space lighting limited to horizontally and vertically classified surfaces by design? If so, could this be documented on SurroundingsLight, and is there a way to include slanted surfaces? If not by design, is there anything an app can do to have the light use the full reconstruction mesh?