BasePart

The Anchored property determines whether the part will be immovable by physics. When enabled, a part will never change position due to gravity, other parts collisions, overlapping other parts, or any other physics-related causes. A part that is not anchored is called unanchored. As a result, two anchored parts will never fire the BasePart.Touched event on each other. An anchored part may still be moved by changing its BasePart.CFrame or BasePart.Position, and it still may have a nonzero BasePart.AssemblyLinearVelocity and BasePart.AssemblyAngularVelocity. Finally, if an unanchored part is joined with an anchored part through an object like a Weld, it too will act anchored. If such a joint breaks the part may be affected by physics again. See Understanding Assemblies for more on this.

Network ownership cannot be set on anchored parts. If a part's anchored status changes on the server, the network ownership of that part will be affected.

local part = script.Parent

-- Create a ClickDetector so we can tell when the part is clicked 
local cd = Instance.new("ClickDetector", part)

-- This function updates how the part looks based on its Anchored state
local function updateVisuals()
	if part.Anchored then
		-- When the part is anchored...
		part.BrickColor = BrickColor.new("Bright red")
		part.Material = Enum.Material.DiamondPlate
	else
		-- When the part is unanchored...
		part.BrickColor = BrickColor.new("Bright yellow")
		part.Material = Enum.Material.Wood
	end
end

local function onToggle()
	-- Toggle the anchored property
	part.Anchored = not part.Anchored
	
	-- Update visual state of the brick
	updateVisuals()
end

-- Update, then start listening for clicks
updateVisuals()
cd.MouseClick:Connect(onToggle)

The angular velocity vector of this part's assembly. It's the rate of change of orientation in radians per second.

Angular velocity is the same at every point of the assembly.

Setting the velocity directly may lead to unrealistic motion. Using Torque or AngularVelocity constraint is preferred, or use BasePart:ApplyAngularImpulse() if you want instantaneous change in velocity.

A position calculated via the mass and position of all the parts in the assembly.

If the assembly has an anchored part, that part's center of mass will be the assembly's center of mass, and the assembly will have infinite mass.

Knowing the center of mass can help the assembly maintain stability. A force applied to the center of mass will not cause angular acceleration, only linear. An assembly with a low center of mass will have a better time staying upright under the effect of gravity.

The linear velocity vector of this part's assembly. It's the rate of change in position of the assembly's center of mass in studs per second.

If you want to know the velocity at a point other than the assembly's center of mass, use BasePart:GetVelocityAtPosition().

Setting the velocity directly may lead to unrealistic motion. Using a VectorForce constraint is preferred, or use BasePart:ApplyImpulse() if you want instantaneous change in velocity.

The sum of the mass of all the parts in this part's assembly. Parts that are Massless and are not the assembly's root part will not contribute to the AssemblyMass.

If the assembly has an anchored part, the assembly's mass is considered infinite. Constraints and other physical interactions between unanchored assemblies with a large difference in mass may cause instabilities.

This property indicates the BasePart automatically chosen to represent the Assembly|assembly's root part. It is the same part that's returned when developers call GetRootPart().

The root part can be changed by changing the RootPriority of the parts in the assembly.

Parts that all share the same AssemblyRootPart are in the same assembly.

For more information on root parts, see Understanding Assemblies.

The BackSurface property determines the type of surface used for the +Z direction of a part. When two parts' faces are placed next to each other, they may create a joint between them. If set to Motor, the BasePart.BackSurfaceInput determines how a motor joint should behave.

Most SurfaceTypes render a texture on the part face if the BasePart.Material is set to Plastic. Some SurfaceTypes - Hinge, Motor and SteppingMotor - will render a 3D adornment instead. If this property is selected in the Properties window, it will be highlighted in the game world similar to that of a SurfaceSelection.

local demoPart = script.Parent

-- Create a billboard gui to display what the current surface type is
local billboard = Instance.new("BillboardGui")
billboard.AlwaysOnTop = true
billboard.Size = UDim2.new(0, 200, 0, 50)
billboard.Adornee = demoPart
local textLabel = Instance.new("TextLabel")
textLabel.Size = UDim2.new(0, 200, 0, 50)
textLabel.BackgroundTransparency = 1
textLabel.TextStrokeTransparency = 0
textLabel.TextColor3 = Color3.new(1, 1, 1) -- White
textLabel.Parent = billboard
billboard.Parent = demoPart

local function setAllSurfaces(part, surfaceType)
	part.TopSurface = surfaceType
	part.BottomSurface = surfaceType
	part.LeftSurface = surfaceType
	part.RightSurface = surfaceType
	part.FrontSurface = surfaceType
	part.BackSurface = surfaceType
end

while true do
	-- Iterate through the different SurfaceTypes
	for _, enum in pairs(Enum.SurfaceType:GetEnumItems()) do
		textLabel.Text = enum.Name
		setAllSurfaces(demoPart, enum)
		task.wait(1)
	end
end

The BottomSurface property determines the type of surface used for the -Y direction of a part. When two parts' faces are placed next to each other, they may create a joint between them. If set to Motor, the BasePart.BottomSurfaceInput determines how a motor joint should behave.

Most SurfaceTypes render a texture on the part face if the BasePart.Material is set to Plastic. Some SurfaceTypes - Hinge, Motor and SteppingMotor - will render a 3D adornment instead. If this property is selected in the Properties window, it will be highlighted in the game world similar to that of a SurfaceSelection.

local demoPart = script.Parent

-- Create a billboard gui to display what the current surface type is
local billboard = Instance.new("BillboardGui")
billboard.AlwaysOnTop = true
billboard.Size = UDim2.new(0, 200, 0, 50)
billboard.Adornee = demoPart
local textLabel = Instance.new("TextLabel")
textLabel.Size = UDim2.new(0, 200, 0, 50)
textLabel.BackgroundTransparency = 1
textLabel.TextStrokeTransparency = 0
textLabel.TextColor3 = Color3.new(1, 1, 1) -- White
textLabel.Parent = billboard
billboard.Parent = demoPart

local function setAllSurfaces(part, surfaceType)
	part.TopSurface = surfaceType
	part.BottomSurface = surfaceType
	part.LeftSurface = surfaceType
	part.RightSurface = surfaceType
	part.FrontSurface = surfaceType
	part.BackSurface = surfaceType
end

while true do
	-- Iterate through the different SurfaceTypes
	for _, enum in pairs(Enum.SurfaceType:GetEnumItems()) do
		textLabel.Text = enum.Name
		setAllSurfaces(demoPart, enum)
		task.wait(1)
	end
end

The BrickColor property determines the color of a part. If the part has a BasePart.Material, this also determines the color used when rendering the material texture. For more control over the color, the BasePart.Color property can be used (it is a Color3 variant of this property). If Color set, this property will use the closest BrickColor.

Other visual properties of a part are determined by BasePart.Transparency and BasePart.Reflectance.

local part = script.Parent

-- Create a ClickDetector so we can tell when the part is clicked 
local cd = Instance.new("ClickDetector", part)

-- This function updates how the part looks based on its Anchored state
local function updateVisuals()
	if part.Anchored then
		-- When the part is anchored...
		part.BrickColor = BrickColor.new("Bright red")
		part.Material = Enum.Material.DiamondPlate
	else
		-- When the part is unanchored...
		part.BrickColor = BrickColor.new("Bright yellow")
		part.Material = Enum.Material.Wood
	end
end

local function onToggle()
	-- Toggle the anchored property
	part.Anchored = not part.Anchored
	
	-- Update visual state of the brick
	updateVisuals()
end

-- Update, then start listening for clicks
updateVisuals()
cd.MouseClick:Connect(onToggle)

The CFrame property determines both the position and orientation of the BasePart in the world. It acts as an arbitrary reference location on the geometry, but ExtentsCFrame represents the actual CFrame of its physical center.

When setting CFrame on a part, other joined parts are also moved relative to the part, but it is recommended that you use PVInstance:PivotTo() to move an entire model, such as when teleporting a player's character.

Unlike setting BasePart.Position, setting BasePart.CFrame will always move the part to the exact given CFrame; in other words: no overlap checking is done and the physics solver will attempt to resolve any overlap unless both parts are Anchored.

For keeping track of positions relative to a part's CFrame, an Attachment may be useful.

local part = script.Parent

-- Reset the part's CFrame to (0, 0, 0) with no rotation.
-- This is sometimes called the "identity" CFrame
part.CFrame = CFrame.new()

-- Set to a specific position (X, Y, Z)
part.CFrame = CFrame.new(0, 25, 10)

-- Same as above, but use a Vector3 instead
local point = Vector3.new(0, 25, 10)
part.CFrame = CFrame.new(point)

-- Set the part's CFrame to be at one point, looking at another
local lookAtPoint = Vector3.new(0, 20, 15)
part.CFrame = CFrame.new(point, lookAtPoint)

-- Rotate the part's CFrame by pi/2 radians on local X axis
part.CFrame = part.CFrame * CFrame.Angles(math.pi / 2, 0, 0)
-- Rotate the part's CFrame by 45 degrees on local Y axis
part.CFrame = part.CFrame * CFrame.Angles(0, math.rad(45), 0)
-- Rotate the part's CFrame by 180 degrees on global Z axis (note the order!)
part.CFrame = CFrame.Angles(0, 0, math.pi) * part.CFrame -- Pi radians is equal to 180 degrees

-- Composing two CFrames is done using * (the multiplication operator)
part.CFrame = CFrame.new(2, 3, 4) * CFrame.new(4, 5, 6) --> equal to CFrame.new(6, 8, 10)

-- Unlike algebraic multiplication, CFrame composition is NOT communitative: a * b is not necessarily b * a!
-- Imagine * as an ORDERED series of actions. For example, the following lines produce different CFrames:
-- 1) Slide the part 5 units on X.
-- 2) Rotate the part 45 degrees around its Y axis.
part.CFrame = CFrame.new(5, 0, 0) * CFrame.Angles(0, math.rad(45), 0)
-- 1) Rotate the part 45 degrees around its Y axis.
-- 2) Slide the part 5 units on X.
part.CFrame = CFrame.Angles(0, math.rad(45), 0) * CFrame.new(5, 0, 0)

-- There is no "CFrame division", but instead simply "doing the inverse operation".
part.CFrame = CFrame.new(4, 5, 6) * CFrame.new(4, 5, 6):inverse() --> is equal to CFrame.new(0, 0, 0)
part.CFrame = CFrame.Angles(0, 0, math.pi) * CFrame.Angles(0, 0, math.pi):inverse() --> equal to CFrame.Angles(0, 0, 0)

-- A reference to some other part
local otherPart = part.Parent.OtherPart

-- Position a part relative to another (in this case, put our part on top of otherPart)
part.CFrame = otherPart.CFrame * CFrame.new(0, part.Size.Y / 2 + otherPart.Size.Y / 2, 0)

-- All of this information applies to SetPrimaryPartCFrame, since that's all tht method
local model = part.Parent.Model
model:SetPrimaryPartCFrame(CFrame.new(0, 25, 0))

CanCollide determines whether a part will physically interact with other parts. When disabled, other parts can pass through the brick uninterrupted. Parts used for decoration usually have CanCollide disabled, as they need not be considered by the physics engine.

If a part is not BasePart.Anchored and has CanCollide disabled, it may fall out of the world to be eventually destroyed by Workspace.FallenPartsDestroyHeight.

When CanCollide is disabled, parts may still fire the BasePart.Touched event (as well the other parts touching them). You can disable this with BasePart.CanTouch.

For more information on collisions, see Collisions.

-- Paste into a Script inside a tall part
local part = script.Parent

local OPEN_TIME = 1

-- Can the door be opened at the moment?
local debounce = false

local function open()
	part.CanCollide = false
	part.Transparency = 0.7
	part.BrickColor = BrickColor.new("Black")
end

local function close()
	part.CanCollide = true
	part.Transparency = 0
	part.BrickColor = BrickColor.new("Bright blue")
end

local function onTouch(otherPart)
	-- If the door was already open, do nothing
	if debounce then
		print("D")
		return
	end

	-- Check if touched by a Humanoid
	local human = otherPart.Parent:FindFirstChildOfClass("Humanoid")
	if not human then
		print("not human")
		return
	end

	-- Perform the door opening sequence
	debounce = true
	open()
	task.wait(OPEN_TIME)
	close()
	debounce = false
end

part.Touched:Connect(onTouch)
close()

CanQuery determines whether the part is considered during spatial query operations, such as GetPartBoundsInBox or Raycast. CanCollide must also be disabled when disabling CanQuery. These functions will never include parts whose CanQuery and CanCollide is false.

Beyond this property, it is also possible to exclude parts which are descendants of a given list of parts using an OverlapParams or RaycastParams object when calling the spatial query functions.

This property determines if Touched and TouchEnded events fire on the part. If true, other touching parts must also have CanTouch set to true for touch events to fire. If false, touch events cannot be set up for the part and attempting to do so will throw an error. Similarly, if the property is set to false after a touch event is connected, the event will be disconnected and the TouchTransmitter removed.

Note that this collision logic can be set to respect collision groups through the Workspace.TouchesUseCollisionGroups property. If true, parts in non-colliding groups will ignore both collisions and touch events, thereby making this property irrelevant.

Performance

There is a small performance gain on parts that have both CanTouch and CanCollide set to false, as these parts will never need to compute any kind of part to part collisions. However, they can still be hit by Raycasts and OverlapParams queries.

Determines whether or not a part casts a shadow.

Note that this feature is not designed for performance enhancement. It should only be disabled on parts where you want to hide the shadows the part casts. Disabling this property for a given part may cause visual artifacts on the shadows cast upon that part.

The CenterOfMass property describes the local position of a part's center of mass. If this is a single part assembly, this is the AssemblyCenterOfMass converted from world space to local. On simple Parts, the center of mass is always (0,0,0). It can vary for WedgePart or MeshPart however.

The CollisionGroup property describes the name of the part's collision group (maximum of 100 characters). Parts start off in the default group whose name is "Default". This value cannot be empty.

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
workspace.BallPart.CollisionGroup = collisionGroupBall
workspace.DoorPart.CollisionGroup = collisionGroupDoor

-- Set groups as non-collidable and check the result
PhysicsService:CollisionGroupSetCollidable(collisionGroupBall, collisionGroupDoor, false)
print(PhysicsService:CollisionGroupsAreCollidable(collisionGroupBall, collisionGroupDoor))  --> false

The Color property determines the color of a part. If the part has a BasePart.Material, this also determines the color used when rendering the material texture. If this property is set, BasePart.BrickColor will use the closest BrickColor to the Color3 value.

Other visual properties of a part are determined by BasePart.Transparency and BasePart.Reflectance.

-- Paste into a Script within StarterCharacterScripts
-- Then play the game, and fiddle with your character's health
local char = script.Parent
local human = char.Humanoid

local colorHealthy = Color3.new(0.4, 1, 0.2)
local colorUnhealthy = Color3.new(1, 0.4, 0.2)

local function setColor(color)
	for _, child in pairs(char:GetChildren()) do
		if child:IsA("BasePart") then
			child.Color = color
			while child:FindFirstChildOfClass("Decal") do
				child:FindFirstChildOfClass("Decal"):Destroy()
			end
		elseif child:IsA("Accessory") then
			child.Handle.Color = color
			local mesh = child.Handle:FindFirstChildOfClass("SpecialMesh")
			if mesh then
				mesh.TextureId = ""
			end
		elseif child:IsA("Shirt") or child:IsA("Pants") then
			child:Destroy()
		end
	end
end

local function update()
	local percentage = human.Health / human.MaxHealth

	-- Create a color by tweening based on the percentage of your health
	-- The color goes from colorHealthy (100%) ----- > colorUnhealthy (0%)
	local color = Color3.new(
		colorHealthy.R * percentage + colorUnhealthy.r * (1 - percentage),
		colorHealthy.G * percentage + colorUnhealthy.g * (1 - percentage),
		colorHealthy.B * percentage + colorUnhealthy.b * (1 - percentage)
	)
	setColor(color)
end

update()
human.HealthChanged:Connect(update)

CurrentPhysicalProperties indicates the current physical properties of the part. You can set custom values for the physical properties per part, custom material, and material override. The Engine prioritizes more granular definitions when determining the effective physical properties of a part. The values in the following list are in order from highest to lowest priority:

• Custom physical properties of the part
• Custom physical properties of the part's custom material
• Custom physical properties of the material override of the part's material
• Default physical properties of the part's material

CustomPhysicalProperties lets you customize various physical aspects of a Part, such as its density, friction, and elasticity.

If enabled, this property let's you configure these physical properties. If disabled, these physical properties are determined by the BasePart.Material of the part. The page for Material contains list of the various part materials.

local part = script.Parent

-- This will make the part light and bouncy!
local DENSITY = 0.3
local FRICTION = 0.1
local ELASTICITY = 1
local FRICTION_WEIGHT = 1
local ELASTICITY_WEIGHT = 1

local physProperties = PhysicalProperties.new(DENSITY, FRICTION, ELASTICITY, FRICTION_WEIGHT, ELASTICITY_WEIGHT)
part.CustomPhysicalProperties = physProperties

When true, and when Workspace.FluidForces is enabled, causes the physics engine to compute aerodynamic forces on this BasePart.

The CFrame of the physical extents of the BasePart, representing its physical center.

The actual physical size of the BasePart as regarded by the physics engine, for example in collision detection.

The FrontSurface property determines the type of surface used for the -Z direction of a part. When two parts' faces are placed next to each other, they may create a joint between them. If set to Motor, the BasePart.FrontSurfaceInput determines how a motor joint should behave.

Most SurfaceTypes render a texture on the part face if the BasePart.Material is set to Plastic. Some SurfaceTypes including Hinge, Motor, and SteppingMotor render a 3D adornment instead. If this property is selected in the Properties window, it will be highlighted in the game world similar to that of a SurfaceSelection.

local demoPart = script.Parent

-- Create a billboard gui to display what the current surface type is
local billboard = Instance.new("BillboardGui")
billboard.AlwaysOnTop = true
billboard.Size = UDim2.new(0, 200, 0, 50)
billboard.Adornee = demoPart
local textLabel = Instance.new("TextLabel")
textLabel.Size = UDim2.new(0, 200, 0, 50)
textLabel.BackgroundTransparency = 1
textLabel.TextStrokeTransparency = 0
textLabel.TextColor3 = Color3.new(1, 1, 1) -- White
textLabel.Parent = billboard
billboard.Parent = demoPart

local function setAllSurfaces(part, surfaceType)
	part.TopSurface = surfaceType
	part.BottomSurface = surfaceType
	part.LeftSurface = surfaceType
	part.RightSurface = surfaceType
	part.FrontSurface = surfaceType
	part.BackSurface = surfaceType
end

while true do
	-- Iterate through the different SurfaceTypes
	for _, enum in pairs(Enum.SurfaceType:GetEnumItems()) do
		textLabel.Text = enum.Name
		setAllSurfaces(demoPart, enum)
		task.wait(1)
	end
end

The LeftSurface property determines the type of surface used for the -X direction of a part. When two parts' faces are placed next to each other, they may create a joint between them. If set to Motor, the BasePart.LeftSurfaceInput determines how a motor joint should behave.

Most SurfaceTypes render a texture on the part face if the BasePart.Material is set to Plastic. Some SurfaceTypes including Hinge, Motor, and SteppingMotor render a 3D adornment instead. If this property is selected in the Properties window, it will be highlighted in the game world similar to that of a SurfaceSelection.

local demoPart = script.Parent

-- Create a billboard gui to display what the current surface type is
local billboard = Instance.new("BillboardGui")
billboard.AlwaysOnTop = true
billboard.Size = UDim2.new(0, 200, 0, 50)
billboard.Adornee = demoPart
local textLabel = Instance.new("TextLabel")
textLabel.Size = UDim2.new(0, 200, 0, 50)
textLabel.BackgroundTransparency = 1
textLabel.TextStrokeTransparency = 0
textLabel.TextColor3 = Color3.new(1, 1, 1) -- White
textLabel.Parent = billboard
billboard.Parent = demoPart

local function setAllSurfaces(part, surfaceType)
	part.TopSurface = surfaceType
	part.BottomSurface = surfaceType
	part.LeftSurface = surfaceType
	part.RightSurface = surfaceType
	part.FrontSurface = surfaceType
	part.BackSurface = surfaceType
end

while true do
	-- Iterate through the different SurfaceTypes
	for _, enum in pairs(Enum.SurfaceType:GetEnumItems()) do
		textLabel.Text = enum.Name
		setAllSurfaces(demoPart, enum)
		task.wait(1)
	end
end

The LocalTransparencyModifier property is a multiplier to BasePart.Transparency that is only visible to the local client. It does not replicate from client to server and is useful for when a part should not render for a specific client, such as how the player does not see their character's body parts when they zoom into first person mode.

This property modifies the local part's transparency through the following formula, with resulting values clamped between 0 and 1.

clientTransparency = 1 - ((1 - part.Transparency) * (1 - part.LocalTransparencyModifier))

The Locked property determines whether a part (or a model it is contained within) may be selected in Roblox Studio by clicking on it. This property is most often enabled on parts within environment models that aren't being edited at the moment. Roblox Studio has a Lock/Unlock All tool that can toggle the Locked state of every part descendant in a model at once.

-- Paste into a Script within a Model you want to unlock
local model = script.Parent

-- This function recurses through a model's heirarchy and unlocks
-- every part that it encounters.
local function recursiveUnlock(object)
	if object:IsA("BasePart") then
		object.Locked = false
	end

	-- Call the same function on the children of the object
	-- The recursive process stops if an object has no children
	for _, child in pairs(object:GetChildren()) do
		recursiveUnlock(child)
	end
end

recursiveUnlock(model)

Mass is a read-only property that describes the product of a part's volume and density. It is returned by the GetMass function.

• The volume of a part is determined by its Size and its Shape, which varies depending on the kind of BasePart used, such as WedgePart.
• The density of a part is determined by its Material or CustomPhysicalProperties, if specified.

If this property is enabled, the BasePart will not contribute to the total mass or inertia of its assembly as long as it is welded to another part that has mass.

If the part is its own root part according to AssemblyRootPart, this will be ignored for that part, and it will still contribute mass and inertia to its assembly like a normal part. Parts that are massless should never become an assembly root part unless all other parts in the assembly are also massless.

This might be useful for things like optional accessories on vehicles that you don't want to affect the handling of the car or a massless render mesh welded to a simpler collision mesh.

See also Understanding Assemblies, an article documenting what root parts are and how to use them.

The Material property allows a builder to set a part's texture and default physical properties (in the case that BasePart.CustomPhysicalProperties is unset). The default Plastic material has a very light texture, and the SmoothPlastic material has no texture at all. Some material textures like DiamondPlate and Granite have very visible textures. Each material's texture reflects sunlight differently, especially Foil.

Setting this property then enabling BasePart.CustomPhysicalProperties will use the default physical properties of a material. For instance, DiamondPlate is a very dense material while Wood is very light. A part's density determines whether it will float in terrain water.

The Glass material changes rendering behavior on moderate graphics settings. It applies a bit of reflectiveness (similar to BasePart.Reflectance) and perspective distortion. The effect is especially pronounced on sphere-shaped parts (set BasePart.Shape to Ball). Semitransparent objects and Glass parts behind Glass are not visible.

local part = script.Parent

-- Create a ClickDetector so we can tell when the part is clicked 
local cd = Instance.new("ClickDetector", part)

-- This function updates how the part looks based on its Anchored state
local function updateVisuals()
	if part.Anchored then
		-- When the part is anchored...
		part.BrickColor = BrickColor.new("Bright red")
		part.Material = Enum.Material.DiamondPlate
	else
		-- When the part is unanchored...
		part.BrickColor = BrickColor.new("Bright yellow")
		part.Material = Enum.Material.Wood
	end
end

local function onToggle()
	-- Toggle the anchored property
	part.Anchored = not part.Anchored
	
	-- Update visual state of the brick
	updateVisuals()
end

-- Update, then start listening for clicks
updateVisuals()
cd.MouseClick:Connect(onToggle)

The system searches the MaterialVariant instance with specified MaterialVariant name and BasePart.Material type. If it successfully finds a matching MaterialVariant instance, it uses this MaterialVariant instance to replace the default material. Default material can be the built-in material or an override MaterialVariant specified in MaterialService.

The Orientation property describes the part's rotation in degrees around the X, Y and Z axes using a Vector3. The rotations are applied in Y → X → Z order. This differs from proper Euler angles and is instead Tait-Bryan angles, which describe yaw, pitch and roll. It is also worth noting how this property differs from the CFrame.Angles() constructor, which applies rotations in a different order (Z → Y → X). For better control over the rotation of a part, it is recommended that BasePart.CFrame is set instead.

When setting this property any Welds or Motor6Ds connected to this part will have the matching C0 or C1 property updated and to allow the part to move relative to any other parts it is joined to.

WeldConstraints will also be temporarily disabled and re-enabled during the move.

local part = script.Parent

local INCREMENT = 360 / 20

-- Rotate the part continually
while true do
	for degrees = 0, 360, INCREMENT do
		-- Set only the Y axis rotation
		part.Rotation = Vector3.new(0, degrees, 0)
		-- A better way to do this would be setting CFrame
		--part.CFrame = CFrame.new(part.Position) * CFrame.Angles(0, math.rad(degrees), 0)
		task.wait()
	end
end

This property specifies the offset of the part's pivot from its CFrame, that is part:GetPivot() is the same as part.CFrame * part.PivotOffset.

This is convenient for setting the pivot to a location in local space, but setting a part's pivot to a location in world space can be done as follows:

local part = workspace.BluePart
local desiredPivotCFrameInWorldSpace = CFrame.new(0, 10, 0)
part.PivotOffset = part.CFrame:ToObjectSpace(desiredPivotCFrameInWorldSpace)

local function resetPivot(model)
	local boundsCFrame = model:GetBoundingBox()
	if model.PrimaryPart then
		model.PrimaryPart.PivotOffset = model.PrimaryPart.CFrame:ToObjectSpace(boundsCFrame)
	else
		model.WorldPivot = boundsCFrame
	end
end

resetPivot(script.Parent)

local function createHand(length, width, yOffset)
	local part = Instance.new("Part")
	part.Size = Vector3.new(width, 0.1, length)
	part.Material = Enum.Material.Neon
	part.PivotOffset = CFrame.new(0, -(yOffset + 0.1), length / 2)
	part.Anchored = true
	part.Parent = workspace
	return part
end

local function positionHand(hand, fraction)
	hand:PivotTo(CFrame.fromEulerAnglesXYZ(0, -fraction * 2 * math.pi, 0))
end

-- Create dial
for i = 0, 11 do
	local dialPart = Instance.new("Part")
	dialPart.Size = Vector3.new(0.2, 0.2, 1)
	dialPart.TopSurface = Enum.SurfaceType.Smooth
	if i == 0 then
		dialPart.Size = Vector3.new(0.2, 0.2, 2)
		dialPart.Color = Color3.new(1, 0, 0)
	end
	dialPart.PivotOffset = CFrame.new(0, -0.1, 10.5)
	dialPart.Anchored = true
	dialPart:PivotTo(CFrame.fromEulerAnglesXYZ(0, (i / 12) * 2 * math.pi, 0))
	dialPart.Parent = workspace
end

-- Create hands
local hourHand = createHand(7, 1, 0)
local minuteHand = createHand(10, 0.6, 0.1)
local secondHand = createHand(11, 0.2, 0.2)

-- Run clock
while true do
	local components = os.date("*t")
	positionHand(hourHand, (components.hour + components.min / 60) / 12)
	positionHand(minuteHand, (components.min + components.sec / 60) / 60)
	positionHand(secondHand, components.sec / 60)
	task.wait()
end

The Position property describes the coordinates of a part using a Vector3. It reflects the position of the part's BasePart.CFrame, however it can also be set.

When setting this property any Welds or Motor6Ds connected to this part will have the matching C0 or C1 property updated and to allow the part to move relative to any other parts it is joined to.

WeldConstraints will also be temporarily disabled and re-enabled during the move.

This returns the time in seconds since the part's physics got last updated on the local client (or the server). Returns 0 when the part has no physics (Anchored)

The Reflectance property determines how much a part reflects the skybox. A value of 0 indicates the part is not reflective at all, and a value of 1 indicates the part should fully reflect.

Reflectance is not affected by BasePart.Transparency, unless the part is fully transparent, in which case reflectance will not render at all. Reflectance may or may not be ignored depending on the BasePart.Material of the part.

local part = script.Parent

local pointLight = Instance.new("PointLight")
pointLight.Brightness = 0
pointLight.Range = 12
pointLight.Parent = part

local touchNo = 0
local function blink()
	-- Advance touchNo to tell other blink() calls to stop early
	touchNo = touchNo + 1
	-- Save touchNo locally so we can tell when it changes globally
	local myTouchNo = touchNo
	for i = 1, 0, -0.1 do
		-- Stop early if another blink started
		if touchNo ~= myTouchNo then
			break
		end
		-- Update the blink animation
		part.Reflectance = i
		pointLight.Brightness = i * 2
		task.wait(0.05)
	end
end

part.Touched:Connect(blink)

The ResizeIncrement property is a read-only property that describes the smallest change in size allowable by the BasePart:Resize() method. It differs between implementations of the BasePart abstract class. For instance, Part has this set to 1 and TrussPart has this set to 2 (since individual truss sections are 2x2x2 in size).

-- Put this Script in several kinds of BasePart, like
-- Part, TrussPart, WedgePart, CornerWedgePart, etc.
local part = script.Parent

-- Create a handles object for this part
local handles = Instance.new("Handles")
handles.Adornee = part
handles.Parent = part

-- Manually specify the faces applicable for this handle
handles.Faces = Faces.new(Enum.NormalId.Top, Enum.NormalId.Front, Enum.NormalId.Left)

-- Alternatively, use the faces on which the part can be resized.
-- If part is a TrussPart with only two Size dimensions
-- of length 2, then ResizeableFaces will only have two
-- enabled faces. For other parts, all faces will be enabled.
handles.Faces = part.ResizeableFaces

The ResizeableFaces property (with an e, not ResizableFaces) describes using a Faces object the different faces on which a part may be resized. For most implementations of BasePart, such as Part and WedgePart, this property includes all faces. However, TrussPart will set its ResizeableFaces set to only two faces since those kinds of parts must have two BasePart.Size dimensions of length 2. This property is most commonly used with tools used for building and manipulating parts and has little use outside of that context. The Handles class, which has the Handles.Faces property, can be used in conjunction with this property to display only the handles on faces that can be resized on a part.

-- Put this Script in several kinds of BasePart, like
-- Part, TrussPart, WedgePart, CornerWedgePart, etc.
local part = script.Parent

-- Create a handles object for this part
local handles = Instance.new("Handles")
handles.Adornee = part
handles.Parent = part

-- Manually specify the faces applicable for this handle
handles.Faces = Faces.new(Enum.NormalId.Top, Enum.NormalId.Front, Enum.NormalId.Left)

-- Alternatively, use the faces on which the part can be resized.
-- If part is a TrussPart with only two Size dimensions
-- of length 2, then ResizeableFaces will only have two
-- enabled faces. For other parts, all faces will be enabled.
handles.Faces = part.ResizeableFaces

The RightSurface property determines the type of surface used for the +X direction of a part. When two parts' faces are placed next to each other, they may create a joint between them. If set to Motor, the BasePart.RightSurfaceInput determines how a motor joint should behave.

Most SurfaceTypes render a texture on the part face if the BasePart.Material is set to Plastic. Some SurfaceTypes including Hinge, Motor, and SteppingMotor will render a 3D adornment instead. If this property is selected in the Properties window, it will be highlighted in the game world similar to that of a SurfaceSelection.

local demoPart = script.Parent

-- Create a billboard gui to display what the current surface type is
local billboard = Instance.new("BillboardGui")
billboard.AlwaysOnTop = true
billboard.Size = UDim2.new(0, 200, 0, 50)
billboard.Adornee = demoPart
local textLabel = Instance.new("TextLabel")
textLabel.Size = UDim2.new(0, 200, 0, 50)
textLabel.BackgroundTransparency = 1
textLabel.TextStrokeTransparency = 0
textLabel.TextColor3 = Color3.new(1, 1, 1) -- White
textLabel.Parent = billboard
billboard.Parent = demoPart

local function setAllSurfaces(part, surfaceType)
	part.TopSurface = surfaceType
	part.BottomSurface = surfaceType
	part.LeftSurface = surfaceType
	part.RightSurface = surfaceType
	part.FrontSurface = surfaceType
	part.BackSurface = surfaceType
end

while true do
	-- Iterate through the different SurfaceTypes
	for _, enum in pairs(Enum.SurfaceType:GetEnumItems()) do
		textLabel.Text = enum.Name
		setAllSurfaces(demoPart, enum)
		task.wait(1)
	end
end

This property is an integer between -127 and 127 that takes precedence over all other rules for root part sort. When considering multiple parts that are not Anchored and which share the same Massless value, a part with a higher RootPriority will take priority over those with lower RootPriority.

You can use this property to control which part of an assembly is the root part and keep the root part stable if size changes.

See also Understanding Assemblies, an article documenting what root parts are and how to use them.

The rotation of the part in degrees for the three axes.

When setting this property any Welds or Motor6Ds connected to this part will have the matching C0 or C1 property updated and to allow the part to move relative to any other parts it is joined to.

WeldConstraints will also be temporarily disabled and re-enabled during the move.

A part's Size property determines its visual dimensions, while ExtentsSize represents the actual size used by the physics engine, for example in collision detection. The individual dimensions (length, width, height) can be as low as 0.001 and as high as 2048. Size dimensions below 0.05 will be visually represented as if the part's dimensions are 0.05.

The size of the part determines its mass which is given by BasePart:GetMass(). A part's Size is used by a variety of other objects:

• ParticleEmitter to determine the area from which particles are spawned.
• BlockMesh to partially determine the rendered rectangular prism.
• SpecialMesh for certain MeshTypes, to determine the size of the rendered mesh.
• SurfaceLight to determine the space to illuminate.

local TOWER_BASE_SIZE = 30

local position = Vector3.new(50, 50, 50)

local hue = math.random()
local color0 = Color3.fromHSV(hue, 1, 1)
local color1 = Color3.fromHSV((hue + 0.35) % 1, 1, 1)

local model = Instance.new("Model")
model.Name = "Tower"

for i = TOWER_BASE_SIZE, 1, -2 do
	local part = Instance.new("Part")
	part.Size = Vector3.new(i, 2, i)
	part.Position = position
	part.Anchored = true
	part.Parent = model
	-- Tween from color0 and color1
	local perc = i / TOWER_BASE_SIZE
	part.Color = Color3.new(
		color0.R * perc + color1.R * (1 - perc),
		color0.G * perc + color1.G * (1 - perc),
		color0.B * perc + color1.B * (1 - perc)
	)

	position = position + Vector3.new(0, part.Size.Y, 0)
end
model.Parent = workspace

The TopSurface property determines the type of surface used for the +Y direction of a part. When two parts' faces are placed next to each other, they may create a joint between them. If set to Motor, the BasePart.TopSurfaceInput determines how a motor joint should behave.

Most SurfaceTypes render a texture on the part face if the BasePart.Material is set to Plastic. Some SurfaceTypes - Hinge, Motor and SteppingMotor - will render a 3D adornment instead. If this property is selected in the Properties window, it will be highlighted in the game world similar to that of a SurfaceSelection.

local demoPart = script.Parent

-- Create a billboard gui to display what the current surface type is
local billboard = Instance.new("BillboardGui")
billboard.AlwaysOnTop = true
billboard.Size = UDim2.new(0, 200, 0, 50)
billboard.Adornee = demoPart
local textLabel = Instance.new("TextLabel")
textLabel.Size = UDim2.new(0, 200, 0, 50)
textLabel.BackgroundTransparency = 1
textLabel.TextStrokeTransparency = 0
textLabel.TextColor3 = Color3.new(1, 1, 1) -- White
textLabel.Parent = billboard
billboard.Parent = demoPart

local function setAllSurfaces(part, surfaceType)
	part.TopSurface = surfaceType
	part.BottomSurface = surfaceType
	part.LeftSurface = surfaceType
	part.RightSurface = surfaceType
	part.FrontSurface = surfaceType
	part.BackSurface = surfaceType
end

while true do
	-- Iterate through the different SurfaceTypes
	for _, enum in pairs(Enum.SurfaceType:GetEnumItems()) do
		textLabel.Text = enum.Name
		setAllSurfaces(demoPart, enum)
		task.wait(1)
	end
end

The Transparency property controls the visibility of a part on a scale of 0 to 1, where 0 is completely visible (opaque), and a value of 1 is completely invisible (not rendered at all).

BasePart.Reflectance can reduce the overall transparency of a brick if set to a value close to 1.

While fully transparent parts are not rendered at all, partially transparent objects have some significant rendering costs. Having many translucent parts may slow down the game's performance.

When transparent parts overlap, render order can act unpredictable - try to keep semi-transparent parts from overlapping to avoid this.

The BasePart.LocalTransparencyModifier is a multiplier to Transparency that is only visible to the local client.

-- Paste into a Script inside a tall part
local part = script.Parent

local OPEN_TIME = 1

-- Can the door be opened at the moment?
local debounce = false

local function open()
	part.CanCollide = false
	part.Transparency = 0.7
	part.BrickColor = BrickColor.new("Black")
end

local function close()
	part.CanCollide = true
	part.Transparency = 0
	part.BrickColor = BrickColor.new("Bright blue")
end

local function onTouch(otherPart)
	-- If the door was already open, do nothing
	if debounce then
		print("D")
		return
	end

	-- Check if touched by a Humanoid
	local human = otherPart.Parent:FindFirstChildOfClass("Humanoid")
	if not human then
		print("not human")
		return
	end

	-- Perform the door opening sequence
	debounce = true
	open()
	task.wait(OPEN_TIME)
	close()
	debounce = false
end

part.Touched:Connect(onTouch)
close()

local function makeXRayPart(part)
	-- LocalTransparencyModifier will make parts see-through but only for the local
	-- client, and it won't replicate to the server
	part.LocalTransparencyModifier = 0.5
end

-- This function uses recursion to search for parts in the game
local function recurseForParts(object)
	if object:IsA("BasePart") then
		makeXRayPart(object)
	end

	-- Stop if this object has a Humanoid - we don't want to see-through players!
	if object:FindFirstChildOfClass("Humanoid") then
		return
	end

	-- Check the object's children for more parts
	for _, child in pairs(object:GetChildren()) do
		recurseForParts(child)
	end
end

recurseForParts(workspace)

Applies an instant angular force impulse to this part's assembly, causing the assembly to spin.

The resulting angular velocity from the impulse relies on the assembly's mass. So a higher impulse is required to move more massive assemblies. Impulses are useful for cases where you want a force applied instantly, such as an explosion or collision.

If the part is owned by the server, this function must be called on a server Script. If the part is owned by a client, this function can be called on a LocalScript or server Script.

Parameters

Returns

This function applies an instant force impulse to this part's assembly.

The force is applied at the assembly's center of mass, so the resulting movement will only be linear.

The resulting velocity from the impulse relies on the assembly's mass. So a higher impulse is required to move more massive assemblies. Impulses are useful for cases where you want a force applied instantly, such as an explosion or collision.

If the part is owned by the server, this function must be called on a server Script. If the part is owned by a client, this function can be called on a LocalScript or server Script.

Parameters

Returns

This function applies an instant force impulse to this part's assembly, at the specified position in world space.

If the position is not at the assembly's center of mass, the impulse will cause a positional and rotational movement.

The resulting velocity from the impulse relies on the assembly's mass. So a higher impulse is required to move more massive assemblies. Impulses are useful for cases where developers want a force applied instantly, such as an explosion or collision.

If the part is owned by the server, this function must be called on a server Script. If the part is owned by a client, this function can be called on a LocalScript or server Script.

Parameters

Returns

Returns whether the parts can collide with each other or not. This function takes into account the collision groups of the two parts. This function will error if the specified part is not a BasePart.

Parameters

Returns

The CanSetNetworkOwnership function checks whether you can set a part's network ownership.

The function's return value verifies whether or not you can call BasePart:SetNetworkOwner() or BasePart:SetNetworkOwnershipAuto() without encountering an error. It returns true if you can modify/read the network ownership, or returns false and the reason you can't, as a string.

Returns

local part = workspace:FindFirstChild("Part")

if part and part:IsA("BasePart") then
	local canSet, errorReason = part:CanSetNetworkOwnership()
	if canSet then
		print(part:GetFullName() .. "'s Network Ownership can be changed!")
	else
		warn("Cannot change the Network Ownership of " .. part:GetFullName() .. " because: " .. errorReason)
	end
end

Parameters

Returns

Returns a table of parts connected to the object by any kind of rigid joint.

If recursive is true this function will return all of the parts in the assembly rigidly connected to the BasePart.

Rigid Joints

When a joint connects two parts together (Part0 → Part1), a joint is rigid if the physics of Part1 are completely locked down by Part0. This only applies to the following joint types:

• Weld
• Snap
• ManualWeld
• Motor
• Motor6D
• WeldConstraint

Parameters

Returns

Return all Joints or Constraints that is connected to this Part.

Returns

GetMass returns the value of the read-only Mass property.

This function predates the Mass property. It remains supported for backward-compatibility; you should use the Mass property directly.

Returns

local myPart = Instance.new("Part")
myPart.Size = Vector3.new(4, 6, 4)
myPart.Anchored = true
myPart.Parent = workspace

local myMass = myPart:GetMass()

print("My part's mass is " .. myMass)

Returns the current player who is the network owner of this part, or nil in case of the server.

Returns

Returns true if the game engine automatically decides the network owner for this part.

Returns

Returns

Returns the base part of an assembly. When moving an assembly of parts using a CFrame. it is important to move this base part (this will move all other parts connected to it accordingly).

More information is available in the Understanding Assemblies article.

This function predates the AssemblyRootPart property. It remains supported for backward-compatibility; you should use the AssemblyRootPart property directly.

Returns

Returns a table of all parts that are physically interacting with this part. If the part itself has CanCollide set to false, then this function returns an empty table unless the part has a TouchInterest object parented to it (meaning something is connected to its Touched event). Parts that are adjacent but not intersecting are not considered touching. This function predates the WorldRoot:GetPartsInPart() function, which provides more flexibility and avoids the special TouchInterest rules described above. Use WorldRoot:GetPartsInPart() instead.

Returns

Returns the linear velocity of the part's assembly at the given position relative to this part. It can be used to identify the linear velocity of parts in an assembly other than the root part. If the assembly has no angular velocity, than the linear velocity will always be the same for every position.

Parameters

Returns

Returns true if the object is connected to a part that will hold it in place (eg an BasePart.Anchored part), otherwise returns false. In an assembly that has an BasePart.Anchored part, every other part is grounded.

Returns

Changes the size of an object just like using the Studio resize tool.

Parameters

Returns

Sets the given player as network owner for this and all connected parts. When playerInstance is nil, the server will be the owner instead of a player.

Parameters

Returns

Lets the game engine dynamically decide who will handle the part's physics (one of the clients or the server).

Returns

Creates a new IntersectOperation from the intersecting geometry of the part and the other parts in the given array. Only Parts are supported, not Terrain or MeshParts. Similar to Clone(), the returned object has no set Parent.

The following properties from the calling part are applied to the resulting IntersectOperation:

• Color, Material, MaterialVariant, Reflectance, Transparency
• CanCollide
• Anchored, Density, Elasticity, ElasticityWeight, Friction, FrictionWeight

In the following image comparison, IntersectAsync() is called on the purple block using a table containing the blue block. The resulting IntersectOperation resolves into a shape of the intersecting geometry of both parts.

Notes

• The original parts remain intact following a successful intersect operation. In most cases, you should Destroy() all of the original parts and parent the returned IntersectOperation to the same place as the calling BasePart.
• By default, the face colors of the resulting intersection are borrowed from the Color property of the original parts. To change the entire intersection to a specific color, set its UsePartColor property to true.
• If an intersect operation would result in a part with more than 20,000 triangles, it will be simplified to 20,000 triangles.

Parameters

Returns

Creates a new UnionOperation from the part, minus the geometry occupied by the parts in the given array. Only Parts are supported, not Terrain or MeshParts. Similar to Clone(), the returned object has no set Parent.

Note that the resulting union cannot be empty due to subtractions. If the operation would result in completely empty geometry, it will fail.

In the following image comparison, SubtractAsync() is called on the blue cylinder using a table containing the purple block. The resulting UnionOperation resolves into a shape that omits the block's geometry from that of the cylinder.

Parameters

Returns

local mainPart = workspace.BlueBlock
local otherParts = {workspace.PurpleCylinder}

-- Perform subtract operation
local success, newSubtract = pcall(function()
    return mainPart:SubtractAsync(otherParts)
end)

-- If operation succeeds, position it at the same location and parent it to the workspace
if success and newSubtract then
    newSubtract.Position = mainPart.Position
    newSubtract.Parent = workspace
end

-- Destroy original parts which remain intact after operation
mainPart:Destroy()
for i = 1, #otherParts do
    otherParts[i]:Destroy()
end

Creates a new UnionOperation from the part, plus the geometry occupied by the parts in the given array. Only Parts are supported, not Terrain or MeshParts. Similar to Clone(), the returned object has no set Parent.

The following properties from the calling part are applied to the resulting UnionOperation:

• Color, Material, MaterialVariant, Reflectance, Transparency
• CanCollide
• Anchored, Density, Elasticity, ElasticityWeight, Friction, FrictionWeight

In the following image comparison, UnionAsync() is called on the blue block using a table containing the purple cylinder. The resulting UnionOperation resolves into a shape of the combined geometry of both parts.

Notes

• The original parts remain intact following a successful union operation. In most cases, you should Destroy() all of the original parts and parent the returned UnionOperation to the same place as the calling BasePart.
• By default, the resulting union respects the Color property of each of its parts. To change the entire union to a specific color, set its UsePartColor property to true.
• If an union operation would result in a part with more than 20,000 triangles, it will be simplified to 20,000 triangles.