Lighting

Light Types

• Directional: Outdoor lights or lights from extreme or near-infinite distances
• Point light: Light bulb style that emit on all directions from a single point
• Spot light : From a single point but limited by a set of cones
• Sky light: Capture background of scene and apply it as light
• Rect: Emit light from a rectecgular plane

Light Mobility

The mobility setting changes how the engine handles lighting and shadowing.

Static

• Lights that cannot change or move in any way at runtime.
• Lighting and shadows precalculated.
• Memory for lightmaps.

Stationary

• Lights that can change some parameters but can not move.
• Bakes light and shadows for static objects also cast dynamic shadows for moveables (only four overlapping)

Movable

• Completly dynamic light and shadows that can change any proptery they have at runtime.
• Lighting and shadows calculated almost every frame

Links

Some brief thoughts on how Nanite in UE5 possibly works....

Some thoughts on Unreal 5's Nanite - in way too many words

UE4 - Physical light unit - Twitter Thread

How Epic Games is handling auto exposure in 4.25

Dynamic Lighting vs Baked Lighting (UE4) - Which Should You Use?

https://www.youtube.com/watch?v=u2AUJLvawCM