BasePart.Touched

The Touched event fires when a part comes in contact with another part. For instance, if PartA bumps into PartB, then PartA.Touched fires with PartB, and PartB.Touched fires with PartA.

This event only fires as a result of physical movement, so it will not fire if the CFrame property was changed such that the part overlaps another part. This also means that at least one of the parts involved must not be Anchored at the time of the collision.

This event works in conjunction with Workspace.TouchesUseCollisionGroups to specify whether collision groups are acknowledged for detection.

Parameters

otherPart: BasePart

The other part that came in contact with the given part.


Code Samples

This code sample creates a BillboardGui on a part that displays the number of parts presently touching it.

Touching Parts Count
local part = script.Parent



local billboardGui = Instance.new("BillboardGui")

billboardGui.Size = UDim2.new(0, 200, 0, 50)

billboardGui.Adornee = part

billboardGui.AlwaysOnTop = true

billboardGui.Parent = part



local tl = Instance.new("TextLabel")

tl.Size = UDim2.new(1, 0, 1, 0)

tl.BackgroundTransparency = 1

tl.Parent = billboardGui



local numTouchingParts = 0



local function onTouch(otherPart)

	print("Touch started: " .. otherPart.Name)

	numTouchingParts = numTouchingParts + 1

	tl.Text = numTouchingParts

end



local function onTouchEnded(otherPart)

	print("Touch ended: " .. otherPart.Name)

	numTouchingParts = numTouchingParts - 1

	tl.Text = numTouchingParts

end



part.Touched:Connect(onTouch)

part.TouchEnded:Connect(onTouchEnded)

This code sample demonstrates how to connect the BasePart.Touched event of multiple parts in a Model to one function.

Model Touched
local model = script.Parent



local function onTouched(otherPart)

	-- Ignore instances of the model coming in contact with itself

	if otherPart:IsDescendantOf(model) then

		return

	end



	print(model.Name .. " collided with " .. otherPart.Name)

end



for _, child in pairs(model:GetChildren()) do

	if child:IsA("BasePart") then

		child.Touched:Connect(onTouched)

	end

end