Since torches prevent mobs from spawning, is it possible to place enough torches within a specific radius to ensure safety during the night? I'm thinking of a situation without any shelter built, more along the lines of a flat plain. If it is possible, how many torches/how far out do I need to go to make that area safe?
Learn about light:
- Sunlight gives 15 luminance to the blocks it hits directly, or through half steps.
- Lava gives 15 luminance.
- Lightstone gives 15 luminance.
- A jack-o-lantern gives 15 luminance.
- A candle gives 14 luminance to the otherwise empty block it occupies.
- A redstone candle gives 7 luminance to the otherwise empty block it occupies.
Every tile that isn't a light source has a luminance of one minus the luminance of its neighbors. For example, if you had a 6 and a 4 luminance sources close to each other, attached to a wall, you'd have this distribution:
1 121 1 12321 121 1234321 1232123454321 123432345654321 12┴─────┴4321 1 12321 121 1
...except this works in three dimensions instead of two!
Learn about spawning:
- The following applies to any difficulty, except for Easy.
- Every tile within 24 distance of the player is not eligible.
- Every tile outside a 144×144 square centered on you is not eligible.
- Every non-glass, non-half step surface in the outer world with 7 or less luminance is eligible for spawning.
- Every non-glass, non-half step surface in the Nether is eligible for spawning.
- Mob spawners cause mob to spawn at a high rate in any surface within 5 distance of it.
Here's what I try to do to ensure a luminance of 7 consistently along a line:
Place the first torch. Pardon my hexadecimal one-sided luminance graph:
Proceed until you find two tiles looking exactly like the next, then go back one.
Plant a torch there. Lo and behold, minimum luminance there will be 8!
You can adapt this algorithm to your necessities with ease. Just plant a torch in the darkest area when in doubt. (Duh.)
- Put torches directly onto surfaces for best results.
In your mining, be aware that any surface is good enough to spawn...
↓↓↓ ↓↓ All positions marked with an arrow are valid ███ ██↓ spawning points, to the best of my knowledge, █ █↓ and they all can lead to the just spawned mob █ █ to reach you. █ ↓█ █↓↓↓↓↓█ Be vigilant and don't mine caves from the ███████ bottom up :(
Learn how to keep mob that has spawned outside: make traps.
- Mobs can only jump up one tile. Make pits deeper than that and, once in, they will be trapped (skeletons are still dangerous and spiders can climb out).
- Mobs cannot deconstruct. Make walls. (Be aware creepers do explode, if they get close enough.) Use cobblestone: they have high explosion resistance and can't catch fire.
- Mobs cannot use items. Protect your entrance with a wooden door. Plant it from the outside, or skeletons will be able to hurt you with their arrows!
- Mobs' path finding is somewhat dumb. Protect your spawn point with water and liberal amounts of cactus (arrange them in a chequered pattern.)
Torches Provide a light level of 14. Note that this is to the block that they are in. Adjacent blocks have a light level of 13. Mobs require a light level of 7 or less to spawn. This means that mobs can't spawn within 7 of a lit torch. So placing a torch every thirteen tiles will keep a hallway lit.
You can expand this to two dimensions by placing a second line of torches 7 to one side and offset by seven.
T____________T______ ____________________ ____________________ ____________________ ____________________ ____________________ ______T____________T
See this post
Mobs will spawn in areas of light 7 or lower. Source
Torches provide a light of 14, with the light value being reduced by 1 for every tile away.
14 13 12 11 10 9 8 9 10 11 12 13 14
Consider the line of light values above. The 14's are torches. If you put the torches no more than 12 squares away, you will prevent any monster from spawning in a straight line; do note however, that if you go with a strictly grid based system, you will have dark "centers" made from the torch squares. I recommend a staggered grid, each line "shifted" 6 squares from the other, so that the light values prevent the centers from getting to dark.
First, some mob spawning science:
- Spawns occur in a 144x144 square around you (assuming a perfectly flat surface), but not within a 24 block radius of you.
- Hostile mobs spawn at light = 7 or less
- A torch provides 14 light to adjacent blocks and one less light per block of distance.
Using these measurements, it looks like you would have to make a grid of torches 13 squares apart that covers a 144x144 block area (excepting the no spawn circle around you, if you like).