How does Minecraft perform lighting?

Question

The only model I'm familiar with is diffuse lighting but this look way more complicated than that.

Answer 1

Each square has a light level from 15 to 0. Each level is 20% less than the level above it. If a square contains a light source it gets the luminosity of that light source, otherwise it gets one less than the brightest neighbor.

Sunlight is special, it suffers no vertical attenuation.

Answer 2

While the answer by Loren is mostly correct, I’d like to add that the minecraftwiki has further information.

Sunlight and moonlight works by essentially making blocks with nothing but air and glass above glow with the current lightness (15 at day, 7 at night and something between at dusk/dawn)

The falloff described by Loren means that level 0 still has 0.8¹⁵·100% = 3.5% lightness (to quote my own edit in the minecraftwiki)

The smooth lighting intruduced with Beta 1.3 works by using the light values of the adjacent blocks to generate a gradient.

Answer 3

If you place a light source on a flat dark place, you will get a square of light, turned around by 45°, with the middle in the light source. The size is equal to the middle light value

Natural light values are:

Clear weather: 15
Rain: 12
Rain with thunder: 10
Night: 4
Night with Rain/Thunder: 4

Note that Thunder Rain will behave like if it was night - you can sleep, mobs spawn, etc.

If this Answer scores 1pt. it's a record!

Answer 4

The light sources in Minecraft are as listed: Of course, sunlight during a thunderstorm and the nether's light are exceptions to the rule: If the light level is UNDER 7, entities will spawn. These are both over 7, but mobs will spawn because in the nether, it acts as if it is night, and because a thunderstorm changes the "time" of the day, mobs do spawn.

Beacon  15
End Portal Block    15
Fire    15
Glowstone   15
Jack o'Lantern  15
Lava    15
Redstone Lamp, when powered 15
Sea Lantern 15
Torch   14
Furnace, when active    13
Glowing Obsidian    12
Nether Portal Block 11
Redstone Ore, when touched  9
Ender Chest 7
Redstone Torch, when on 7
Brewing Stand   1
Brown Mushroom  1
Dragon Egg  1
End Portal block    1

Other

Sunlight    15
Sunlight, during Rain or Snowfall   12
Sunlight, during a Thunderstorm 10
Moonlight   4

(Cited from this website: https://minecraft.gamepedia.com/Light#Sources_of_light)