PhysicsService
PhysicsService primarily contains methods for working with collision groups which define whether a set of parts may or may not collide with parts in other collision groups. You can register a collision group through RegisterCollisionGroup() and assign parts to it by setting those parts' CollisionGroup property to the name of the collision group.
Creating, deleting, and modifying collision relationships between collision groups is limited to server-side Scripts.
See Collision Filtering for usage details in Studio and within scripts.
Summary
Methods
Returns whether the part is in the collision group.
Sets the collision status between two groups.
Returns whether the two groups will collide.
Creates a new collision group with the given name, and returns the ID of the created group.
Returns the ID of the collision group with the specified name.
Returns the name of the group with the corresponding ID.
Returns a table with info on all of the place's collision groups.
Returns the maximum number of collision groups.
Returns a table with info on all of the place's collision groups.
Checks if a collision group is registered.
Registers a new collision group with the given name.
Removes the collision group with the given name.
Renames specified collision group.
Sets the collision group of a part.
Unregisters the collision group for the given name.
Properties
Methods
CollisionGroupContainsPart
Returns whether the specified part is in the specified collision group. This method will throw a runtime error in the following circumstances:
- The specified group does not exist.
- The specified part is not a BasePart.
Parameters
Returns
CollisionGroupSetCollidable
Sets the collision status between two groups. This method will throw an error if either of the groups is unregistered, so it's recommended that you confirm each group's registration through PhysicsService:IsCollisionGroupRegistered() before making this call.
Parameters
Returns
CollisionGroupsAreCollidable
Returns whether the two specified collision groups will collide. This method will also return true if either of the groups are unregistered, as the default collision mask collides with all groups.
Parameters
Returns
CreateCollisionGroup
Creates a new collision group with the given name, and returns the ID of the created group.
Parameters
Returns
GetCollisionGroupId
This method returns the ID of the collision group with the specified name. It will throw an error if no group with the given name exists.
Parameters
The name of the collision group being retrieved.
Returns
The ID of the retrieved collision group, or nil if no such group exists.
GetCollisionGroupName
Returns the name of the collision group with the corresponding ID. This method will return nil if the group with the corresponding ID has not been named.
Parameters
Returns
GetCollisionGroups
Returns a table with info on all of the place's collision groups. Each value in the returned table is itself a table containing three members:
| Member | Type | Description |
|---|---|---|
| id | integer | The ID of the group. |
| mask | integer | The collision group's mask; only for internal use. |
| name | string | The name of the collision group. |
Returns
GetMaxCollisionGroups
Returns the maximum number of collision groups the engine supports. This value is currently 32.
Returns
GetRegisteredCollisionGroups
Returns a table with info on all of the place's collision groups. Each value in the returned table is itself a table and containing two members:
| Member | Type | Description |
|---|---|---|
| mask | integer | The collision group's mask; only for internal use. |
| name | string | Name of the collision group. |
Returns
IsCollisionGroupRegistered
Checks if a collision group is registered. It's recommended that you call this method before calling methods that throw errors for unregistered collision groups, such as PhysicsService:CollisionGroupSetCollidable().
Parameters
Returns
RegisterCollisionGroup
Registers a new collision group with the given name. The name cannot be "Default".
Note that this method has a slight performance overhead based on the number of BaseParts in the workspace, so it's recommended that you register all collision groups at edit time through the Studio editor and call UnregisterCollisionGroup() and RenameCollisionGroup() as infrequently as possible.
Parameters
Returns
Code Samples
This example demonstrates one basic use of collision groups. It assigns BallPart to "CollisionGroupBall" and DoorPart to "CollisionGroupDoor", then makes the two groups non-collidable using PhysicsService:CollisionGroupSetCollidable().
local PhysicsService = game:GetService("PhysicsService")
local collisionGroupBall = "CollisionGroupBall"
local collisionGroupDoor = "CollisionGroupDoor"
-- Register collision groups
PhysicsService:RegisterCollisionGroup(collisionGroupBall)
PhysicsService:RegisterCollisionGroup(collisionGroupDoor)
-- Assign parts to collision groups
script.Parent.BallPart.CollisionGroup = collisionGroupBall
script.Parent.DoorPart.CollisionGroup = collisionGroupDoor
-- Set groups as non-collidable with each other and check the result
PhysicsService:CollisionGroupSetCollidable(collisionGroupBall, collisionGroupDoor, false)
print(PhysicsService:CollisionGroupsAreCollidable(collisionGroupBall, collisionGroupDoor)) --> false
RemoveCollisionGroup
Removes the collision group with the given name. If an invalid name is provided, this method will not do anything, although if the reserved name "Default" is provided, it will throw an error. If there are any parts in the collision group when it is removed, these parts will still maintain the same collision group ID. The physical behavior of parts in a removed group is undefined, so it is recommended to move any parts in a removed group to another group. This method will throw a runtime error in the following circumstances:
- The name "Default" is provided.
- The method is called from a client.
Parameters
Returns
RenameCollisionGroup
Renames the specified registered collision group, but does not rename the CollisionGroup property of parts that utilize the group. The first argument of this method is the name of the group to rename, the second argument is the new name for the group. If the specified group does not exist, this method will not do anything. The naming conventions for the new name follow the same rules as if the group was being created with RegisterCollisionGroup().
This method will throw a runtime error in the following circumstances:
- Invalid or empty name provided for either argument.
- The method is called from a client.
Note that this method has a slight performance overhead based on the number of BaseParts in the workspace, so it's recommended that you register all collision groups at edit time through the Studio editor and rename them as infrequently as possible.
Parameters
Returns
SetPartCollisionGroup
This method sets the collision group of the specified part to the group with the specified name. It is equivalent to setting the BasePart.CollisionGroupId, although calling this method is the recommended approach.
This method will throw a runtime error in the following circumstances:
- The part parameter is not a BasePart instance.
- The specified group does not exist.
Parameters
The part being set.
The name of collision group that the part's collision group is being set to.
Returns
UnregisterCollisionGroup
Unregisters the collision group for the given name, with the following behaviors:
- If an invalid name is provided, the method will not do anything.
- If the reserved name "Default" is provided or if the method is called from a client, it will throw an error.
- If there are any parts in the collision group when it is removed, those parts will still maintain the same collision group name. The physical behavior of parts in a removed group is undefined, so it's recommended to move any parts in a removed group to another group, such as the "Default" group.
Note that this method has a slight performance overhead based on the number of BaseParts in the workspace, so it's recommended that you register all collision groups at edit time through the Studio editor and call this method as infrequently as possible.