An explosion is a physical event, generally destructive, that can be caused by several different circumstances. It can destroy nearby blocks, propel and damage nearby players, entities, and their armor, and cause one or more fires under correct circumstances. Explosions produce a "shockwave" particle effect.
Multiple close explosions may propel objects further, but have no cumulative effect on the destruction of a block. This is because explosions' damage to blocks is evaluated individually (per explosion), and blocks' blast resistance does not become "weakened" per explosion.
"Destroyed" blocks have a chance of dropping as collectible resources (and otherwise disappear), and this chance is 1⁄p, where p is the explosion power. So, a creeper blast (uncharged) will have a 1⁄3 chance of dropping a block.
The propulsion effect of explosions is often used for TNT cannons, and can also be used to shoot out gravity affected blocks.
Explosion strength[επεξεργασία | επεξεργασία κώδικα]
|Wither (when created)||7|
|Ender crystal (when attacked)||6|
|Bed (when used in the Nether or the End)||5||Starts fires|
|Ghast fireball||1||Starts fires|
|Black wither skull||1|
|Blue wither skull||1||Treats blast radius blocks (except bedrock, end portal frames, and barriers) as having a blast resistance of no more than 4.|
Effect[επεξεργασία | επεξεργασία κώδικα]
Model of block destruction[επεξεργασία | επεξεργασία κώδικα]
An explosion can destroy nearby blocks. Its blast effect is evaluated independently on many explosion rays originating from the explosion center, as shown in the right figure.
- A cube around the explosion is divided into a 16×16×16 grid, and rays are created from the center to each outer point of this grid
- Each ray is given an intensity, calculated as (0.7 + [a random value from 0 to 0.6]) × [power]
- For every 0.3 blocks along the ray, the intensity of the ray decays/is attenuated by 0.3×0.75 (0.225), and the block it passes through absorbs/reduces it by ([blast resistance/5]+0.3)×0.3
- The ray destroys all blocks that could not end the ray at any checkpoint
From the above process, the following results can be deduced (where ⌊x⌋ is the floor function):
- The blast radius in the air of an explosion (i.e. only attenuated, not absorbed by blocks) = == 10.2 (charged creepers), 6.9 (TNT), 5.1 (creepers), 1.5 (fireballs). For example, a TNT explosion can destroy a torch 7 blocks away. But how many blocks an explosion can destroy is non-deterministic and also dependent on the specific location of the explosion.
- The minimum block resistance required to absorb maximum blast force of an explosion happening in nearby air = ((1.3 × power − attenuation steps × step length × 0.75)/step length − 0.3) × 5. To not be destroyed, a block has to absorb all blast force at the first checkpoint in it.
- The attenuation steps is subject to collision restrictions. For explosion in air, there is at least one attenuation step. TNT and creeper explosion are always 0.49 and 0.5 meter away from nearest block (2 att. steps), but fireball explosion can happen anywhere (1 att. step).
- Thus, the block resistances are 121.00 (charged creepers), 77.67 (TNT), 56.00 (creepers), 16.42 (fireballs).
- So water, lava (Note: Only the stationary block) obsidian, and bedrock are always indestructible, and fences and less blast-resistant blocks can be destroyed by fireballs. These are theoretical values, and in reality less resistant blocks are not always destroyed, and since Minecraft is supposed to be simple, there is no such mechanic.
Interaction with entities[επεξεργασία | επεξεργασία κώδικα]
An explosion has different effects on entities than blocks. Entities are damaged and propelled by an explosion if within its damage radius of 2 × power. Note that the "damage radius" is different from the blast radius of explosion effect on blocks.
- For every entity within a 2×[power] block sphere of the explosion center, the impact is (1-[distance from explosion/power/2])×[exposure] (see section below on exposure)
- The entity is damaged by (impact×impact+impact)×8×power+1 (armor enchantments for damage are handled separately)
- After damage, exposure is reduced by (exposure×[max blast protection from all armor]×0.15)
- The entity's eyes are propelled along the ray from the explosion center by the new exposure
From the above process, the following results can be deduced:
- Entities will always get at least 1 point of damage if they are within the radius, regardless of their explosion exposure.
- The maximum damage that entities can take (at the explosion center with 100% exposure) = (1 × 1 + 1) × 8 × power + 1 point of damage = 97 (charged creeper), 65 (TNT), 49 (creepers), 17 (fireballs). When entities are away or covered by blocks from the explosion center, they take less damage.
- The maximum velocity gain that an entity can obtain from a TNT explosion is 1, at the explosion center with 100% exposure.
Calculation of explosion exposure[επεξεργασία | επεξεργασία κώδικα]
- The entity's bounding box is divided into a [2×width+1] by [2×height+1] by [2×depth+1] grid of unequally spaced points
- A ray is drawn from the explosion center to each point
- The exposure of the entity is the percentage of these rays that are unobstructed
The approximation algorithm has sampling error that results in directional asymmetry of propulsion. For example, a typical TNT cannon has maximum range in the west direction partly because the primed TNT has largest sampled exposure in that direction.
Causing fire[επεξεργασία | επεξεργασία κώδικα]
If the explosion has the ability, it randomly starts fires in ⅓ of all destroyed air blocks that are above opaque blocks.
Prolonged lag[επεξεργασία | επεξεργασία κώδικα]
In addition to the initial lag from processing the explosion, which subsides once the explosion has occurred, there can also be a prolonged fallout from an explosion, that consists of dropped items, liquid-physics, and increased render-complexity of the crater. Technically the dropped items will disappear after 5 minutes, however those 5 in-game minutes may take a long time to process during extreme lag.
Using certain rules and commands can avoid this prolonged lag: setting the gamerule
doTileDrops to false, for instance with
/gamerule doTileDrops false, will stop dropped items from being generated by explosions. Also, the command
/kill @e[type=Item] will destroy all dropped items.
Blast resistance[επεξεργασία | επεξεργασία κώδικα]
|Block name||Blast resistance|
|Lapis Lazuli Block||15|
|Lapis Lazuli Ore||15|
|Nether Quartz Ore||15|
|Nether Wart Block||5|
|End Stone Bricks||4|
|Block of Quartz||4|
|Red Sandstone Stairs||4|
|Block name||Blast resistance|
|Weighted Pressure Plate||2.5|
|Stained Glass Pane||1.5|
Typical damage radius[επεξεργασία | επεξεργασία κώδικα]
The player will receive damage, if within these radii of a 100% exposure ground 1-block, 2-blocks, or 4-blocks of TNT explosion, with the amount of damage labeled on each circle in the figures below.
History[επεξεργασία | επεξεργασία κώδικα]
|0.24||Creepers were first introduced in on August 24, 2009, based on a failed pig model Notch had created.|
|0.26 SURVIVAL TEST 9||TNT was added.|
|January 22, 2010||Explosions are now "better".|
|January 25, 2010||Explosions now lose power when going through stronger materials.|
|1.2.0||Added Ghasts, which shoot explosive ghast fireballs.|
|1.5||Creepers become charged when struck by lightning, increasing the explosion's radius and strength.|
|1.6||Trying to sleep in the Nether causes the bed to explode.|
|1.8||Explosions will now emit shockwave particles after exploding. Prior to Beta 1.8, explosions only emitted smoke.|
|Sound Update||The 'Sound Update' of November 13th 2011 gave TNT a new explosion sound.|
|1.0.0||Beta 1.9-pre3||Bed and ghast explosions cause fire.|
|Beta 1.9-pre4||Trying to sleep in the End causes the bed to explode.|
|Enchantment "Blast Protection" added, protecting against explosions.|
|Beta 1.9-pre6||Ender Crystal added, an entity which sits atop of a block of bedrock. It can be destroyed with a melee or hit with an arrow or snowball, causing an explosion.|
|1.3.1||12w24a||Fixed explosions not pushing back players.|
|1.3.1||Explosions damage the player different amounts on different difficulties, and no damage is dealt to the player on peaceful.|
|1.4.2||12w34a||Added the Wither, which shoots black wither skulls.|
|12w37a||Wither will make a massive explosion upon its creation after its health is fully charged.|
|Blue wither skulls added.|
|12w38b||New Creeper fall mechanics; Creepers will explode if they fall on the player from a certain height.|
|1.5||Destroyed blocks have a 1/power chance of dropping as items; previously it was a fixed 30% chance.|
|1.8.2||Explosions are no longer directionally biased.|
|Pocket Edition Alpha|
|0.2.1||TNT actually explodes.|
|0.12.1||Added explosion particles.|
|0.14.0||An invalid mixture of liquids in cauldrons will result in an non-damaging explosion effect.|
Trivia[επεξεργασία | επεξεργασία κώδικα]
- Explosions with a power greater than 100 look mostly the same from the outside, as only certain lines are used to determine if a block breaks. However, some of those lines continue underground.
- An explosion powerful enough to break bedrock would have a blast radius of over 30,000,000 blocks. If it were an uninterrupted blast, it would cover 238,775,501.2 blocks. However, explosions only follow certain lines, not every block (see previous).
- However, this would not drop the bedrock.
- Explosions going off in flowing water or lava will apply propulsion to entities, but won't affect any blocks, regardless of the blocks' blast resistance.
- Underwater explosions won't emit smoke particles.
- Explosions can redirect projectiles, including Ender Pearls.
- Explosions can break blocks on the other side of surviving blast-resistant blocks.
- Explosions will propel dead mobs' bodies if they go off just after the mob dies.
- If primed TNT explodes in a large, solid cube of stone blocks, it will create an exact 3x3x3 cube inside.
- Experimentation confirms that a TNT detonation will cause a 3x3 hole in a solid block of anything with a blast resistance less than that of water, but more than 12.5 (e.g. crafting tables). This implies that 3x3 is the minimum possible result of a TNT detonation without the blast being resisted altogether.
- If a Falling Sand entity falls into Primed TNT when in water, it will do block damage.