Sky Atmosphere
Physically based sky and sunlight
Also known as: Unreal Sky Atmosphere · Physically based sky · Sun and sky · Procedural sky · Sky light
Definition
A sky atmosphere is a physically based model of the sky that calculates how sunlight scatters through the air, giving realistic blue skies, red sunsets and haze toward the horizon. In Unreal Engine the Sky Atmosphere component works with a Directional Light as the sun and a Sky Light that lights the scene from the sky. The sky changes with the sun's direction, so a time of day can be set by rotating the sun. Unity HDRP offers a Physically Based Sky.
In production
Use it for outdoor scenes with a changing time of day, and pair it with height fog, volumetric clouds and a sky light that recaptures the sky as lighting. For stylized projects, a painted sky or a gradient sky texture is simpler and gives full art direction. Keep the sun intensity and exposure consistent, so the sky and the scene look right together.
Tools that use Sky Atmosphere
See also
Height Fog
Fog that is denser near the ground
Image-Based Lighting
Lighting a scene from an environment image
HDRI
High Dynamic Range Image lighting
Global Illumination
Light bouncing between surfaces
Exposure
Overall brightness of the camera image
Lumen
UE5 dynamic global illumination
Environment Scene Looks Flat
No sense of depth or scale