# 🏃 Move#

#bs.move:help

Make your entity move exactly the way you want them to!

“There is nothing permanent except change.”

—Heraclitus

## 🔧 Functions#

You can find below all functions available in this module.

### Canonical to local#

#bs.move:canonical_to_local

Convert a canonical velocity (using the relative reference frame) into a local velocity (using the local reference frame).

Inputs:

Execution rotated as <entity> or rotated <h> <v>: Rotation used for the conversion.

Scores @s bs.vel.[x,y,z]: Velocity to convert.

Outputs:

Scores @s bs.vel.[x,y,z]: Converted velocity.

Credits: Aksiome

### Local to canonical#

#bs.move:local_to_canonical

Convert a local velocity (using the local reference frame) into a canonical velocity (using the relative reference frame).

Inputs:

Execution rotated as <entity> or rotated <h> <v>: Rotation used for the conversion.

Scores @s bs.vel.[x,y,z]: Velocity to convert.

Outputs:

Scores @s bs.vel.[x,y,z]: Converted velocity.

Credits: Aksiome

### Set motion#

#bs.move:set_motion_by_vel {scale:<scaling>}

Set the motion of an entity using velocity scores.

Inputs:

Execution as <entities>: Entity to move.

Scores @s bs.vel.[x,y,z]: Velocity vector.

Macro Var scale: Scalar for the function’s outputs.

Outputs:

State: Motion is applied to the given entity.

Move a pig by its velocity scores:

# Once
summon minecraft:pig ~ ~ ~
scoreboard players set @e[type=minecraft:pig] bs.vel.x 50
scoreboard players set @e[type=minecraft:pig] bs.vel.y 25
scoreboard players set @e[type=minecraft:pig] bs.vel.z 0

# In a loop
execute as @e[type=minecraft:pig] run function #bs.move:set_motion_by_vel {scale:0.001}


Credits: Aksiome

### Teleport#

#bs.move:tp_by_vel {scale:<scaling>}

Teleport an entity by its velocity scores while handling collisions.

Inputs:

Execution as <entities>: Entity to move.

Scores @s bs.vel.[x,y,z]: Canonical velocity vector.

Scores @s bs.[height,width]: Entity size (in miliblocks). Default to Minecraft size if not defined.

Storage bs:in move:

 on_collision [string] Function run on collision (default: #bs.move:on_collision/slide). block_collision [bool] Whether the entity should collide with blocks (default: true). entity_collision [bool] Whether the entity should collide with entities (default: false). ignored_blocks [string] Blocks to ignore (default: #bs.hitbox:intangible). solid_entities [string] Tag for entities that will be checked (default: bs.move.is_solid).

Macro Var scale: Scalar for the function’s outputs.

Outputs:

State: Entity is teleported according to its velocity scores.

#bs.move:tp_by_local_vel {scale:<scaling>}

Teleport an entity by its velocity scores, using the local reference frame, while handling collisions.

Inputs:

Execution as <entities>: Entity to move.

Scores @s bs.vel.[x,y,z]: Local velocity vector.

Scores @s bs.[height,width]: Entity size (in miliblocks). Default to Minecraft size if not defined.

Storage bs:in move:

 on_collision [string] Function run on collision (default: #bs.move:on_collision/slide). block_collision [bool] Whether the entity should collide with blocks (default: true). entity_collision [bool] Whether the entity should collide with entities (default: false). ignored_blocks [string] Blocks to ignore (default: #bs.hitbox:intangible). solid_entities [string] Tag for entities that will be checked (default: bs.move.is_solid).

Macro Var scale: Scalar for the function’s outputs.

Outputs:

State: Entity is teleported according to its local velocity scores.

Move a cube (block_display) by its velocity scores:

# Once
summon minecraft:block_display ~ ~ ~ {block_state:{Name:"stone"},teleport_duration:3,transformation:[1f,0f,0f,-0.5f,0f,1f,0f,0f,0f,0f,1f,-0.5f,0f,0f,0f,1f]}
scoreboard players set @e[type=minecraft:block_display] bs.vel.x 100
scoreboard players set @e[type=minecraft:block_display] bs.vel.y 20
scoreboard players set @e[type=minecraft:block_display] bs.vel.z 50
scoreboard players set @e[type=minecraft:block_display] bs.width 1000
scoreboard players set @e[type=minecraft:block_display] bs.height 1000

# In a loop
execute as @e[type=minecraft:block_display] run function #bs.move:tp_by_vel {scale:0.001}

# Choose between multiple collision behaviors
data modify storage bs:in move.on_collision set value "#bs.move:on_collision/bounce"
data modify storage bs:in move.on_collision set value "#bs.move:on_collision/damped_bounce"
data modify storage bs:in move.on_collision set value "#bs.move:on_collision/slide"
data modify storage bs:in move.on_collision set value "#bs.move:on_collision/stick"


Performance tip

Although this system doesn’t set specific limits, it’s important to note that performance is influenced by both the speed and size of the entity.

Credits: Aksiome

## 🎓 Custom collisions#

This module allows you to customize collision behaviors according to your specific needs.

By modifying the bs:in move.on_collision storage, you have the freedom to specify the function that triggers upon collision. However, managing the resolution yourself can be quite challenging. This is why Bookshelf provides several predefined functions:

 #bs.move:on_collision/bounce The entity will bounce on the collision surface. #bs.move:on_collision/damped_bounce The entity speed is reduced by 2 on each bounce. #bs.move:on_collision/slide The entity will stick and slide along the collision surface. #bs.move:on_collision/stick The entity will stop and stick to the collision surface.

### How it works?#

The simplest collision resolution is to stop the movement.

bs.move:collision/resolution/stick

# set all components to 0 to cancel the movement
scoreboard players set @s bs.vel.x 0
scoreboard players set @s bs.vel.y 0
scoreboard players set @s bs.vel.z 0


For sliding, we need to cancel the velocity on the axis that was hit and continue traveling the remaining distance.

bs.move:collision/resolution/slide

# get a vector that represent the remaining distance to travel
execute unless score #move.cf bs.data matches 4..5 store result storage bs:ctx x double .001 run scoreboard players operation #move.vx bs.data -= #move.rx bs.data
execute unless score #move.cf bs.data matches 2..3 store result storage bs:ctx z double .001 run scoreboard players operation #move.vz bs.data -= #move.rz bs.data
execute unless score #move.cf bs.data matches 0..1 store result storage bs:ctx y double .001 run scoreboard players operation #move.vy bs.data -= #move.ry bs.data

# set a component to 0 depending on the surface that was hit
execute if score #move.cf bs.data matches 4..5 store result storage bs:ctx x double .001 run scoreboard players set @s bs.vel.x 0
execute if score #move.cf bs.data matches 2..3 store result storage bs:ctx z double .001 run scoreboard players set @s bs.vel.z 0
execute if score #move.cf bs.data matches 0..1 store result storage bs:ctx y double .001 run scoreboard players set @s bs.vel.y 0

# travel the remaining distance
execute at @s run function bs.move:tp_by_vel/apply with storage bs:ctx


To simplify the creation of these behaviors, there’s no need to handle a local velocity directly. The vector is automatically converted before and after the collision resolution. If you need help with custom collisions, you can ask us on our discord server!

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