# How do I rotate from the edge of a part instead of the center position of a part

I am trying to make a door that opens when you touch it, but I want it to rotate from the edge of a part instead of the center of the part if that is possible.

Actually heres a better link https://developer.roblox.com/en-us/articles/CFrame-Math-Operations#rotating-a-door

Why canâ€™t find the surface property in the partâ€™s properties so I can put a hinge on it, but I can find it in the baseplate?

Roblox is in the process of deprecating hinges and motors if im correct.

that is strange though, I wonder if itâ€™s intentional

But the hinge constraints donâ€™t have a cframe property, which means you canâ€™t do anything with them?

Surfaces hinges never had a CFrame afaik

So how am I susposed to make a door then?

You could probably rig it up with constraints (and I recommend that if its an option). If you want to set cframe directly though you could do something like this:

``````local door = workspace.Door

local hingeOffset = CFrame.new(door.Size.X / 2, 0, 0)

local invHingeOffset = hingeOffset:Inverse()
local baseCFrame = door.CFrame * hingeOffset

local function SetHingeAngle(angle)
door.CFrame = baseCFrame * CFrame.Angles(0, angle, 0) * invHingeOffset
end

-- e.g.
local a = 0
while wait() do
a += 0.05
SetHingeAngle(a)
end
``````
2 Likes

I think CFrame:ToWorldSpace() and ToObjectSpace() would do that, you get the cornerâ€™s CFrame relative to the center CFrame, rotate that CFrame around 0,0,0 and then use ToWorldSpace to convert that corner back to global world space, and then use some math to make the center look where it was looking relative to the corner