Align something to a parts axis

[PVP_Player2373902 (Kai)]

Hi everyone!

I am having a problems with forcing a part to follow the mouse on a parts axis (The part is rotated). This video here explains it:

How can I achieve this?

[azqjanna]

Can you show the code you are using to choose the position?

[PVP_Player2373902 (Kai)]

The problem is that I don’t know how I can implement anything needed to solve this situation.

[azqjanna]

Its fine this time but next time copy and paste the text, otherwise if I need to copy and paste something to show you a change I can’t.

[PVP_Player2373902 (Kai)]

local GlowingPart = Instance.new("Part")
	GlowingPart.Size = Vector3.new(Item.Cube.Size.X + 0.05, Item.Cube.Size.Y + 0.05, 0.05)
	GlowingPart.Color = Color3.fromRGB(255, 255, 255)
	GlowingPart.Material = Enum.Material.Neon
	GlowingPart.CanCollide = false
	GlowingPart.Parent = game.Workspace
	
	RunServiceConnection = RunService.RenderStepped:Connect(function()
		GlowingPart.CFrame = CFrame.new(Item.Cube.Position.X, Item.Cube.Position.Y, GetMouse.Hit.Z) * CFrame.Angles(0, math.rad(-Item.Cube.Rotation.Y), 0)
	end)

[azqjanna]

You’re trying to get it to slide like this right?

[PVP_Player2373902 (Kai)]

Yeah. I want to use the axis of the part depending on its rotation like in this picture.

[azqjanna]

Subtract the cube position from the mouse position.
Take that and Dot it with Cube.CFrame * YourAxis (for example Vector3.zAxis), this is the distance along the desired axis with 0 being aligned with the cube center.
Set the glowing part’s CFrame to the Cube’s CFrame + distance * YourAxis

[PVP_Player2373902 (Kai)]

is this right?

RunServiceConnection = RunService.RenderStepped:Connect(function()
	local SubtractCubePosFromMousePos = GetMouse.Hit.Position - Item.Cube.Position
	local Distance = SubtractCubePosFromMousePos:Dot(Item.Cube.CFrame * Vector3.zAxis)
		
	GlowingPart.CFrame = Item.Cube.CFrame + Distance * Vector3.zAxis
end)

(I might only answer in a few hours again because its really late over here)

[azqjanna]

Yes but I realized I made a mistake, use this:

RunServiceConnection = RunService.RenderStepped:Connect(function()
	local SubtractCubePosFromMousePos = GetMouse.Hit.Position - Item.Cube.Position
	local WorldAxis = Item.Cube.CFrame:VectorToWorldSpace(Vector3.zAxis)
	local Distance = SubtractCubePosFromMousePos:Dot(WorldAxis)
		
	GlowingPart.CFrame = Item.Cube.CFrame + WorldAxis * Distance
end)