Weld

Inherits from: JointInstance → Instance → Object

An object used to hold two objects together in a relative position, regardless of whether they're touching. This object is placed inside of a BasePart and the Part1 property determines which other part should be welded to the original part. Two CFrames, C0 and C1, then determine how the parts should be placed.

See also RigidConstraint for a newer alternative using the constraints system that does not require C0 or C1, but instead uses Attachments to control offsets through Constraint.Attachment0 and Constraint.Attachment1.

While the weld is Active, it maintains the part positions such that:

part1.CFrame * C1 == Part0.CFrame * C0

Root Part

Every assembly has a root part (see BasePart:GetRootPart()). When a weld's C0/C1 is modified, the root part will stay where it was.

Directionality

Welds do not have any directionality. Imagine rigid joints forming a tree, branching up from the root part such that all the parts up the tree from the root will move and their welded "children" will move with them.

Inherits from: JointInstance

Memory category: BaseParts

Properties

Inherited from JointInstance

Name	Type / Returns	Description
JointInstance.Active	boolean	Determines if the joint is currently active in the world.
JointInstance.C0	CFrame	Determines how the offset point is attached to `JointInstance.Part0`.
JointInstance.C1	CFrame	Subtracted from the `C0` property to create an offset point for `Part1`.
JointInstance.Enabled	boolean	Sets whether the joint is active or not.
JointInstance.Part0	BasePart	The first `BasePart` that the joint connects.
JointInstance.Part1	BasePart	The second `BasePart` that the joint connects.
JointInstance.part1	BasePart

Inherited from Instance

Name	Type / Returns	Description
Instance.Archivable	boolean	Determines if an `Instance` and its descendants can be cloned using `Instance:Clone()`, and can be saved/published.
Instance.archivable	boolean
Instance.Capabilities	SecurityCapabilities	The set of capabilities allowed to be used for scripts inside this container.
Instance.IsInSandbox	boolean	Indicates whether the instance is inside a sandboxed container.
Instance.Name	string	A non-unique identifier of the `Instance`.
Instance.Parent	Instance	Determines the hierarchical parent of the `Instance`.
Instance.PredictionMode	PredictionMode	Reflects the client-side prediction mode applied to the instance under server-authoritative physics.
Instance.RobloxLocked	boolean	A deprecated property that used to protect `CoreGui` objects.
Instance.Sandboxed	boolean	When enabled, the instance can only access abilities in its `Capabilities` list.
Instance.UniqueId	UniqueId	A unique identifier for the instance.

Inherited from Object

Name	Type / Returns	Description
Object.ClassName	string	A read-only string representing the class this `Object` belongs to.
Object.className	string

Methods

Inherited from Instance

Name	Type / Returns	Description
Instance:AddTag	()	Applies a tag to the instance.
Instance:children	Instances	Returns an array of the object's children.
Instance:ClearAllChildren	()	This method destroys all of an instance's children.
Instance:Clone	Instance	Create a copy of an instance and all its descendants, ignoring instances that are not `Archivable`.
Instance:clone	Instance
Instance:Destroy	()	Sets the `Instance.Parent` property to `nil`, locks the `Instance.Parent` property, disconnects all connections, and calls `Destroy()` on all children.
Instance:destroy	()
Instance:FindFirstAncestor	Instance?	Returns the first ancestor of the `Instance` whose `Instance.Name` is equal to the given name.
Instance:FindFirstAncestorOfClass	Instance?	Returns the first ancestor of the `Instance` whose `Object.ClassName` is equal to the given className.
Instance:FindFirstAncestorWhichIsA	Instance?	Returns the first ancestor of the `Instance` for whom `Object:IsA()` returns true for the given className.
Instance:FindFirstChild	Instance?	Returns the first child of the `Instance` found with the given name.
Instance:findFirstChild	Instance
Instance:FindFirstChildOfClass	Instance?	Returns the first child of the `Instance` whose `ClassName` is equal to the given class name.
Instance:FindFirstChildWhichIsA	Instance?	Returns the first child of the `Instance` for whom `Object:IsA()` returns true for the given className.
Instance:FindFirstDescendant	Instance?	Returns the first descendant found with the given `Instance.Name`.
Instance:GetActor	Actor?	Returns the `Actor` associated with the Instance, if any.
Instance:GetAttribute	Variant	Returns the value which has been assigned to the given attribute name.
Instance:GetAttributeChangedSignal	RBXScriptSignal	Returns an event that fires when the given attribute changes.
Instance:GetAttributes	Dictionary	Returns a dictionary of the instance's attributes.
Instance:GetChildren	Instances	Returns an array containing all of the instance's children.
Instance:getChildren	Instances
Instance:GetDebugId	string	Returns a coded string of the debug ID used internally by Roblox.
Instance:GetDescendants	Instances	Returns an array containing all of the descendants of the instance.
Instance:GetFullName	string	Returns a string describing the instance's ancestry.
Instance:GetStyled	Variant	Returns the styled or explicitly modified value of the specified property, or else the default property value if it hasn't been styled/modified.
Instance:GetStyledPropertyChangedSignal	RBXScriptSignal	Returns an event that fires when the given style property changes on the instance.
Instance:GetTags	Array	Gets an array of all tags applied to the instance.
Instance:HasTag	boolean	Check whether the instance has a given tag.
Instance:IsAncestorOf	boolean	Returns true if an `Instance` is an ancestor of the given descendant.
Instance:IsDescendantOf	boolean	Returns `true` if an `Instance` is a descendant of the given ancestor.
Instance:isDescendantOf	boolean
Instance:IsPropertyModified	boolean	Returns `true` if the value stored in the specified property is not equal to the code-instantiated default.
Instance:QueryDescendants	Instances	Returns an array containing all descendants of the instance that match the `selector` string.
Instance:Remove	()	Sets the object's `Parent` to `nil`, and does the same for all its descendants.
Instance:remove	()
Instance:RemoveTag	()	Removes a tag from the instance.
Instance:ResetPropertyToDefault	()	Resets a property to its default value.
Instance:SetAttribute	()	Sets the attribute with the given name to the given value.
Instance:WaitForChild	Instance	Returns the child of the `Instance` with the given name. If the child does not exist, it will yield the current thread until it does.

Inherited from Object

Name	Type / Returns	Description
Object:GetPropertyChangedSignal	RBXScriptSignal	Get an event that fires when a given property of the object changes.
Object:IsA	boolean	Returns true if an object's class matches or inherits from a given class.
Object:isA	boolean

Events

Inherited from Instance

Name	Type / Returns	Description
Instance.AncestryChanged		Fires when the `Instance.Parent` property of this object or one of its ancestors is changed.
Instance.AttributeChanged		Fires whenever an attribute is changed on the `Instance`.
Instance.ChildAdded		Fires after an object is parented to this `Instance`.
Instance.childAdded
Instance.ChildRemoved		Fires after a child is removed from this `Instance`.
Instance.DescendantAdded		Fires after a descendant is added to the `Instance`.
Instance.DescendantRemoving		Fires immediately before a descendant of the `Instance` is removed.
Instance.Destroying		Fires immediately before (or is deferred until after) the instance is destroyed via `Instance:Destroy()`.
Instance.StyledPropertiesChanged		Fires whenever any style property is changed on the instance, including when a property is set to `nil`.

Inherited from Object

Name	Type / Returns	Description
Object.Changed		Fires immediately after a property of the object changes, with some limitations.