Light

Light (or lighting) in Minecraft affects visibility, mob spawning, and plant growth.

Brightness

Lighting curves. Horizontal axis is block light, vertical is sky light.

There are 16 light levels, which are specified by an integer from 0 (the minimum) to 15 (the maximum). The game uses the light level of a block to compute the brightness of a given block.

The brightness of a block depends on both the level of light from other blocks and the level of sky light. Note "sky light" here is not reduced at night, instead the brightness curve itself changes based on the time. In this it matches the sky lighting value on the debug screen.

In general, lighting due to blocks results in a higher brightness, which is balanced by the fact that light due to blocks effectively starts at 14 (solid light-source blocks emit a level of 15, but that's for the light source block itself) while sky-light brightness is 15 outdoors. Light due to blocks also tends towards orange in the middle ranges, while sky light in the Overworld daytime is white.

In the Overworld with the "Moody" brightness setting, full daylight reaches 98% brightness, while at night brightness is reduced to about 17% and is shaded blue. Full darkness is about 5% brightness.

In the Nether, sky lighting doesn't play a role since there is no source of sky light (although if there were, it would reach about 99% brightness.) Full darkness with the "Moody" brightness setting is at about 25% brightness, which is only slightly darker than a block light level of 7 and no sky light in the Overworld, and is shaded orange like block light.

In the End, sky lighting wouldn't play a role even if there were a source of sky light; this can also be seen if lightning is summoned in the End, there is no flash of brightness like there is in other dimensions. Full darkness in the End with the "Moody" brightness setting is about 28% brightness, and is shaded towards a bluish-green rather than the orange of the Nether and of block lighting.

Spread

T	13	12	11	10	9	8	9	10	11	12	13	T
13	12	11	10	9	8	9	8	9	10	11	12	13
12	11	10	9	8	9	10	9	8	9	10	11	12
11	10	9	8	9	10	11	10	9	8	9	10	11
10	9	8	9	10	11	12	11	10	9	8	9	10
9	8	9	10	11	12	13	12	11	10	9	8	9
8	9	10	11	12	13	T	13	12	11	10	9	8

The light from light-emitting blocks decreases by one light-level for each meter (block) of distance from the light source. Note that this applies to each of the 3 axes including N/S, E/W, and up/down. This fact is significant for preventing hostile mob spawning. If a torch (level 14) is placed on a wall two blocks up from the floor, the light level on the floor one block away from the wall will be 11 (e.g. 14 minus 2 down, minus 1 south). If the torch were placed on the floor at floor level, then the light level on the floor one block away from the wall will be 13 (e.g. 14 minus 0 down, minus 1 south).

Light decreases diagonally by "taxicab distance", or the sum of the distance along each axis. This means that if a torch (level 14) is placed on the floor, the light level on the adjacent floor blocks in all four direction will be 13 while the diagonal blocks in all four directions will have light level 12 (e.g. 14 minus 1 south, minus 1 east). Along a floor, this effect produces a diamond-shaped pattern of illumination around the light source. Remember, light decrease takes place in three dimensions. This means that if a torch (level 14) is placed on a wall one block up from the floor, then the block on the floor that is diagonally one block way will have a light level of 11 (e.g. 14 minus 1 south, minus 1 east, minus 1 down).

Sources of light

Comparison of the different light levels that blocks emit.

Blocks

The following values are the brightness of the block itself:

Icon	Block	Light Level
	Beacon	15
	End Portal (block)	15
	Fire	15
	Glowstone	15
25px	Jack o'Lantern	15
	Lava	15
25px	Redstone Lamp, when powered	15
	Sea Lantern	15
	End Rod	14
	Torch	14
25px	Furnace, when active	13
	Glowing Obsidian	12
25px	Nether Portal (block)	11
	Redstone Ore, when touched	9
	Ender Chest	7
25px	Redstone Torch, when on	7
	Magma Block	3
	Brewing Stand	1
	Brown Mushroom	1
	Dragon Egg	1
	End Portal Frame	1

Other

Icon	Source	Light Level
	Sunlight	15
	Sunlight, during Rain or Snowfall	12
	Sunlight, during a Thunderstorm	10
	Moonlight	4

Light-filtering blocks

How ice affects light. Click through to see it animated between ice and water.

Opaque blocks prevent the spread of light; a 21×21 square of opaque material is enough to spawn mobs in the shadow underneath. By contrast, some transparent blocks such as glass and portal interiors have no effect on light level. All other transparent blocks reduce the spread of light.

Leaves and cobwebs do not have any extra effect on block light, but they do diffuse sky light. The light level from sunlight or moonlight is the same in each block of air in the column of air above the highest obstruction in the column. When placed, leaves and cobwebs obstruct that light column so that the lowest air block above the leaves acts as other light sources do. As you descend below the leaves, the light level diminishes with distance like it would from other light sources such as torches. To control this effect, create an opaque 1×1 chimney with leaves at its opening above you.

The following values are the amount each block decreases the light value. The light emitted decreases by one for each block of distance from the light source, more depending on the block through which it passes.

Icon	Block	Amount of decrease
	Farmland	Full decrease as if opaque
	Slab
	Stairs
	Ice	2
	Water
25px	Cobweb	None, but diffuses sky light at the top-most block
25px	Leaves

Effects of light

Note: Keep in mind that light level is only one of the considerations that apply to mob spawning and plant growth.

Mobs

	Level 0–3	Level 4-7	Level 8	Level 9	Level 10	Level 11	Level 12	Level 13–15
Bats	Spawn at y: 0-62	Spawn at y: 0-62 from October 20th to November 3rd	Do not spawn
Blazes	Spawn in Nether Fortresses						Hostile, do not spawn
Wither skeletons	Spawn in Nether Fortresses		Hostile, do not spawn
Silverfish	Spawn in the Overworld						Hostile, do not spawn
Slimes	Spawn in swamp biomes at y: 51–69		Spawn in certain chunks in most biomes (except mushroom island, the Nether, the End, and the Void) at y: 0–40
Zombies Skeletons	Spawn in the Overworld		Hostile, do not spawn				Hostile, burns in sunlight
Creepers Witches	Spawn in the Overworld		Hostile, do not spawn
Spiders Cave spiders	Spawn in the Overworld		Hostile, do not spawn				Do not spawn, neutral unless provoked
Endermen	Spawn in the Overworld, the Nether and the End		Do not spawn, neutral unless provoked				Do not spawn, teleports randomly and often ignores players when in sunlight

Blocks

	Level 0–3	Level 4-7	Level 8	Level 9	Level 10	Level 11	Level 12	Level 13–15
Snow layers Ice	Forms, does not melt					Forms and melts	Melts
Mushrooms	Spread							Uproot unless on mycelium or podzol
Saplings Pumpkin or Melon stems	Does not grow			Grows
Wheat Carrots Potatoes Beetroots	Uproot		Does not grow	Grows
Grass Block Mycelium	Becomes dirt if opaque block or partially transparent block on top	Does not spread		Spreads to nearby dirt (see below)
Dirt	Does not accept spread	Accepts spread if no opaque or partially transparent block on top

Other

	Level 0–3	Level 4-7	Level 8	Level 9	Level 10	Level 11	Level 12	Level 13–15
Ambience	On			Off

Smooth lighting

The difference between Smooth Lighting on and off.

Smooth lighting (which includes ambient occlusion as well as interpolating lighting across block faces) is a lighting engine that blends light levels and darkens corners to add semi-realistic shadows and glowing from light sources.

This lighting engine is set on by default, and can be set to minimum, maximum, or off by accessing Video Options from the Options menu.

Video

Note: This video is outdated, as several new light sources (sea lanterns, end rods, etc) have since been added.

History

Classic
?				The lighting engine in Classic was very simple, since there were only two light levels, bright and dark. "Sunlight" is emitted by the top edge of the map and will hit any block that is under it, regardless of distance. It will pass through transparent blocks to light blocks underneath. Blocks that do not receive light are in a dim shadow that remains at the same level of brightness no matter how far they are from a light source.
Indev
0.31				Added 16 degrees of brightness, with a maximum of 15 for full daylight and a minimum of 0 for almost complete darkness. Brightness is a linear scale and represents its value divided by 15; for example 15 is 100% (15⁄15) and 13 is 86.67% (13⁄15).
				Sunlight now has a maximum light value of 15, and steadily decreases from dusk, until it reaches a night-time minimum value of 4, representing moonlight.
Alpha
?				Lighting is no longer linear.
				Each brightness value below 15 is 80% as bright as the one above it. For example, 14 is 80% as bright as 15, and 13 is 64% as bright as 15.
				Sunlight now has its own light array and optimizations to make dawn and dusk smoother. During dusk, nighttime, and dawn, a "darkness" value is subtracted from the sky to create the effects of different times of day.
1.2.0		Halloween Update		Added the Nether, where light decreases by 10% each level, rather than the normal 20%.
				Hostile mobs could spawn in higher light levels at lower depths, using the formula 16 − (Layer / 8). At level 8 and below, mobs could spawn even in sunlight.
1.2.1				Notch reverted mob spawning to the original method, saying, "It was way too annoying. I have plans on what to do with this."
Beta
1.3				Smooth lighting engine added with the help of MrMessiah.
1.8				Implemented a new lighting engine. The lighting on a block is given a tint based on the most prominent source of light.
				Day/night cycles no longer require chunk updates and is a smooth transition.
				Artificial light now gives a very subtle "flicker."
				Added void fog, which increases darkness at extreme depths.
Official release
1.4.2		12w39a		Dinnerbone fixed black patches in world generation, and began overhauling the lighting systems such as changing the lighting of blocks to allow for directional lighting.
1.5		13w05a		Improved lighting interaction with stairs.
		13w06a		Several lighting optimizations.
		13w09a		Added three different levels of smooth lighting: Off, Minimum, and Maximum. Minimum uses the old Smooth Lighting, and Maximum fixes a bug with stairs.
1.7.2				Black patches in world generation and structure generation were made a lot less common.
1.8		14w30a		The lighting engine was significantly improved, removing most black spots present in world generation.
		14w34c		The void fog and particles were removed in order to improve performance.
				Redstone repeaters no longer emit light.

Issues

Issues relating to “Light” are maintained on the issue tracker. Report issues there.

Trivia

• In Minecraft's source code, the luminescences are defined using the floating point values in the third column. In a weird quirk, these floating point numbers are fractions of 16, but are multiplied by 15 to get the integer light value.
  • This means that both 0/16 and 1/16 (0.0 and 0.0625) correspond to the integer light value 0.

Gallery

• 2012-03-11 15.00.48.png

  Lighting, the wool block is exposed to sunlight ("Moody" brightness setting).

• 2012-03-11 15.00.53.png

  Lighting, the wool block is exposed to sunlight ("Bright" brightness setting).

• 

  Lighting in the Void. Particles and entities are illuminated based on the light level at level 0.

References

Environment

View at: Template:Environment/content [edit]