BasePartクラス

クラスInstance.newでは作れない日本語解説あり

ひとことで言うと

Part・MeshPartなど、ゲームの世界に置かれる「形のある部品」すべての元になるクラスです。位置・大きさ・色・固定（Anchored）・当たり判定などを決めます。

公式の説明（英語）：The abstract base class for in-world objects that physically interact.

BasePart自体は直接作れません（Instance.newで作るのは Part などの子クラスです）。ここにあるプロパティやイベントは、Part・MeshPart・SpawnLocationなどで共通して使えます。

使用例

ふれたプレイヤーを倒すブロック（キルブロック）

Script置く場所：パーツの中

local part = script.Parent :: BasePart

part.Touched:Connect(function(hit)
	local character = hit.Parent
	if not character then
		return
	end
	local humanoid = character:FindFirstChildWhichIsA("Humanoid")
	if humanoid then
		humanoid.Health = 0
	end
end)

ふれると消える床

Script置く場所：パーツの中

local part = script.Parent :: BasePart
local debounce = false

part.Touched:Connect(function(hit)
	if debounce then
		return
	end
	local character = hit.Parent
	if not character or not character:FindFirstChildWhichIsA("Humanoid") then
		return
	end
	debounce = true
	task.wait(0.5)
	part.Transparency = 1
	part.CanCollide = false
	task.wait(3)
	part.Transparency = 0
	part.CanCollide = true
	debounce = false
end)

スクリプトは、Luauの型チェック（luau-lsp）で確認しています。

クラスの関係

受け継いでいるクラス：Object → Instance → PVInstance → BasePart

このクラスを受け継ぐクラス：Terrain、CornerWedgePart、FormFactorPart、TriangleMeshPart、TrussPart、VehicleSeat

プロパティ（40）

名前と書き方	説明
Anchored `BasePart.Anchored: boolean`	trueにすると、パーツが空中に固定され、物理の力（重力など）で動かなくなります。Determines whether a part is immovable by physics.
AssemblyAngularVelocity `BasePart.AssemblyAngularVelocity: Vector3`	The angular velocity of the part's assembly.
AssemblyCenterOfMass `BasePart.AssemblyCenterOfMass: Vector3`	The center of mass of the part's assembly in world space.
AssemblyLinearVelocity `BasePart.AssemblyLinearVelocity: Vector3`	パーツ（とつながったパーツ全体）の速度。値を入れると、その方向に飛ばせます。The linear velocity of the part's assembly.
AssemblyMass `BasePart.AssemblyMass: float`	The total mass of the part's assembly.
AssemblyRootPart `BasePart.AssemblyRootPart: BasePart`	A reference to the root part of the assembly.
AudioCanCollide `BasePart.AudioCanCollide: boolean`	Determines whether the part will physically interact with audio simulation, similar to Class.BasePart.CastShadow\|CastShadow for lighting.
BackSurface `BasePart.BackSurface: SurfaceType`	Determines the type of surface for the back face of a part.
BottomSurface `BasePart.BottomSurface: SurfaceType`	Determines the type of surface for the bottom face of a part.
BrickColor `BasePart.BrickColor: BrickColor`	パーツの色を、名前の付いた色（BrickColor）で指定します。Determines the color of a part.
CanCollide `BasePart.CanCollide: boolean`	falseにすると、プレイヤーや他のパーツがすり抜けられるようになります。Determines whether a part may collide with other parts.
CanQuery `BasePart.CanQuery: boolean`	Determines whether the part is considered during spatial query operations.
CanTouch `BasePart.CanTouch: boolean`	falseにすると、Touchedイベントが発生しなくなります。Determines if Class.BasePart.Touched\|Touched and Class.BasePart.TouchEnded\|TouchEnded events fire on the part.
CastShadow `BasePart.CastShadow: boolean`	Determines whether or not a part casts a shadow.
CenterOfMass `BasePart.CenterOfMass: Vector3`	Describes the local position of a part's center of mass, relative to its Class.BasePart.CFrame\|CFrame.
CFrame `BasePart.CFrame: CFrame`	パーツの位置と向きをまとめて表す値（CFrame）。Determines the position and orientation of the BasePart in the world.
CollisionGroup `BasePart.CollisionGroup: string`	Describes the name of a part's collision group.
Color `BasePart.Color: Color3`	パーツの色（Color3）。Determines the color of a part.
CurrentPhysicalProperties `BasePart.CurrentPhysicalProperties: PhysicalProperties`	Indicates the current physical properties of the part.
CustomPhysicalProperties `BasePart.CustomPhysicalProperties: PhysicalProperties`	Determines several physical properties of a part.
EnableFluidForces `BasePart.EnableFluidForces: boolean`	Used to enable or disable aerodynamic forces on parts and assemblies.
ExtentsCFrame `BasePart.ExtentsCFrame: CFrame`	The CFrame of the physical extents of the BasePart.
ExtentsSize `BasePart.ExtentsSize: Vector3`	The actual physical size of the BasePart as regarded by the physics engine.
FrontSurface `BasePart.FrontSurface: SurfaceType`	Determines the type of surface for the front face of a part.
LeftSurface `BasePart.LeftSurface: SurfaceType`	Determines the type of surface for the left face of a part.
Locked `BasePart.Locked: boolean`	Determines whether a part is selectable in Studio.
Mass `BasePart.Mass: float`	パーツの重さ。読み取り専用です。Describes the mass of the part, the product of its density and volume.
Massless `BasePart.Massless: boolean`	Determines whether the part contributes to the total mass or inertia of its rigid body.
Material `BasePart.Material: Material`	パーツの素材（木・金属・ネオンなど）。見た目と音が変わります。Determines the texture and default physical properties of a part.
MaterialVariant `BasePart.MaterialVariant: string`	The name of MaterialVariant.
PivotOffset `BasePart.PivotOffset: CFrame`	Specifies the offset of the part's pivot from its CFrame.
Reflectance `BasePart.Reflectance: float`	反射の強さ。0〜1で指定します。Determines how much a part reflects the skybox.
ResizeableFaces `BasePart.ResizeableFaces: Faces`	Describes the faces on which a part may be resized.
ResizeIncrement `BasePart.ResizeIncrement: int`	Describes the smallest change in size allowable by the Class.BasePart:Resize()\|Resize() method.
RightSurface `BasePart.RightSurface: SurfaceType`	Determines the type of surface for the right face of a part.
RootPriority `BasePart.RootPriority: int`	The main rule in determining the root part of an assembly.
Rotation `BasePart.Rotation: Vector3`	The rotation of the part in degrees for the three axes.
Size `BasePart.Size: Vector3`	パーツの大きさ（Vector3）。Determines the dimensions of a part (length, height, width).
TopSurface `BasePart.TopSurface: SurfaceType`	Determines the type of surface for the top face of a part.
Transparency `BasePart.Transparency: float`	透明度。0で不透明、1で完全に見えなくなります。Determines how much a part can be seen through (the inverse of part opacity).

メソッド（24）

名前と書き方	説明
AngularAccelerationToTorque `BasePart:AngularAccelerationToTorque(angAcceleration: Vector3, angVelocity: Vector3): Vector3`	Returns the torque needed to achieve a given angular acceleration on this part's assembly, optionally accounting for gyroscopic effects.
ApplyAngularImpulse `BasePart:ApplyAngularImpulse(impulse: Vector3): ()`	Apply an angular impulse to the assembly.
ApplyImpulse `BasePart:ApplyImpulse(impulse: Vector3): ()`	パーツに瞬間的な力を加えます。Apply an impulse to the assembly at the assembly's Class.BasePart.AssemblyCenterOfMass\|center of mass.
ApplyImpulseAtPosition `BasePart:ApplyImpulseAtPosition(impulse: Vector3, position: Vector3): ()`	Apply an impulse to the assembly at specified position.
BindToCollisionSummaries `BasePart:BindToCollisionSummaries(callback: Function): RBXScriptConnection`	Subscribes to detailed per-frame contact data for the collisions this part is involved in.
CanCollideWith `BasePart:CanCollideWith(part: BasePart): boolean`	Returns whether the parts can collide with each other.
CanSetNetworkOwnership `BasePart:CanSetNetworkOwnership(): Tuple`	Checks whether you can set a part's network ownership.
GetClosestPointOnSurface `BasePart:GetClosestPointOnSurface(position: Vector3): Vector3`	Returns the closest point on the part's surface to the given point.
GetConnectedParts `BasePart:GetConnectedParts(recursive: boolean): List<BasePart>`	Returns a table of parts connected to the object by any kind of rigid joint.
GetJoints `BasePart:GetJoints(): Instances`	Returns all Joints or Constraints connected to this part that are active in the simulation.
GetMass `BasePart:GetMass(): float`	Returns the value of the Class.BasePart.Mass\|Mass property.
GetNetworkOwner `BasePart:GetNetworkOwner(): Instance`	Returns the current player who is the network owner of this part, or nil in case of the server.
GetNetworkOwnershipAuto `BasePart:GetNetworkOwnershipAuto(): boolean`	Returns true if the game engine automatically decides the network owner for this part.
GetNoCollisionConstraints `BasePart:GetNoCollisionConstraints(): Instances`	Returns the enabled NoCollisionConstraint objects currently registered for this part in its physics world.
GetTouchingParts `BasePart:GetTouchingParts(): Instances`	今ふれているパーツをすべて返します。Returns a table of all BasePart.CanCollide true parts that intersect with this part.
GetVelocityAtPosition `BasePart:GetVelocityAtPosition(position: Vector3): Vector3`	Returns the linear velocity of the part's assembly at the given position relative to this part.
IntersectAsync `BasePart:IntersectAsync(parts: Instances, collisionfidelity: CollisionFidelity, renderFidelity: RenderFidelity): Instance`	Creates a new IntersectOperation from the overlapping geometry of the part and the other parts in the given array.
IsGrounded `BasePart:IsGrounded(): boolean`	Returns true if the object is connected to a part that will hold it in place (eg an Class.BasePart.Anchored\|Anchored part), otherwise returns false.
Resize `BasePart:Resize(normalId: NormalId, deltaAmount: int): boolean`	Changes the size of an object just like using the Studio resize tool.
SetNetworkOwner `BasePart:SetNetworkOwner(playerInstance: Player): ()`	Sets the given player as network owner for this and all connected parts.
SetNetworkOwnershipAuto `BasePart:SetNetworkOwnershipAuto(): ()`	Lets the game engine dynamically decide who will handle the part's physics (one of the clients or the server).
SubtractAsync `BasePart:SubtractAsync(parts: Instances, collisionfidelity: CollisionFidelity, renderFidelity: RenderFidelity): Instance`	Creates a new UnionOperation from the part, minus the geometry occupied by the parts in the given array.
TorqueToAngularAcceleration `BasePart:TorqueToAngularAcceleration(torque: Vector3, angVelocity: Vector3): Vector3`	Returns the angular acceleration that would result from applying a given torque to this part's assembly, optionally accounting for gyroscopic effects.
UnionAsync `BasePart:UnionAsync(parts: Instances, collisionfidelity: CollisionFidelity, renderFidelity: RenderFidelity): Instance`	Creates a new UnionOperation from the part, plus the geometry occupied by the parts in the given array.

イベント（2）

名前と書き方	説明
Touched `BasePart.Touched(otherPart: BasePart)`	他のパーツがふれたときに発生するイベントです。ふれたパーツが引数で渡されます。Fires when a part touches another part as a result of physical movement.
TouchEnded `BasePart.TouchEnded(otherPart: BasePart)`	ふれていたパーツが離れたときに発生するイベントです。Fires when a part stops touching another part as a result of physical movement.

受け継いでいるメンバー

PVInstance から受け継いでいるもの（4）

Origin・Pivot Offset・GetPivot・PivotTo

Instance から受け継いでいるもの（46）

Archivable・Capabilities・IsInSandbox・Name・Parent・PredictionMode・Sandboxed・AddTag・ClearAllChildren・Clone・Destroy・FindFirstAncestor・FindFirstAncestorOfClass・FindFirstAncestorWhichIsA・FindFirstChild・FindFirstChildOfClass・FindFirstChildWhichIsA・FindFirstDescendant・GetActor・GetAttribute・GetAttributeChangedSignal・GetAttributes・GetChildren・GetDebugId・GetDescendants・GetFullName・GetStyled・GetStyledPropertyChangedSignal・GetTags・HasTag・IsAncestorOf・IsDescendantOf・IsPropertyModified・QueryDescendants・RemoveTag・ResetPropertyToDefault・SetAttribute・WaitForChild・AncestryChanged・AttributeChanged・ChildAdded・ChildRemoved・DescendantAdded・DescendantRemoving・Destroying・StyledPropertiesChanged

Object から受け継いでいるもの（4）

ClassName・GetPropertyChangedSignal・IsA・Changed

BasePartを使う記事

英語の説明とメンバーの一覧は、Roblox Creator Documentation（BasePart）をもとにしています（CC BY 4.0）。日本語の解説は、このサイトで独自に書いたものです。

執筆：鈴木孝昌官公庁のWeb・システム開発を担当する現役プロジェクトマネージャー。沖縄マイクラ部クロスウェーブで、ロブロックス（Roblox）・マインクラフト（マイクラ）・Scratchなどのプログラミングを指導。マイクラカップ沖縄代表チームを指導（第6回・第7回、第7回TBS賞）。
沖縄マイクラ部で、子どもたちにロブロックス（Roblox）やマインクラフト（マイクラ）のプログラミングを教えています。プロフィールと編集方針
Instagramで教室の様子を見る
noteで記事を読む

出典

Roblox Creator Documentation（BasePart）