How to get the position of a rotated object?

[KrimsonWoIf (ClassicDev)]

Hello, I’m trying to get the position of the end of the part event when its rotated.

---

lets inspect how this might work:

As you can see, normally I would do +Size/2 to get the end of a part. However, look at how this equation would work on a rotated part:

---

As you can see on a rotated part, this position would not be the correct one. So how do I ensure that the position I am getting is correct, even when the part is rotated, so it would look like this?

---

[123marble]

This is basic trig, but luckily CFrames can do this calculation for you.

Use part.CFrame * CFrame.new(part.Size.X/2, 0, 0)

[KrimsonWoIf (ClassicDev)]

so lets say I wanted to check if a rotated part was beyond the position 10 studs on the X axis. I could do:

local cf = part.CFrame * CFrame.new(part.Size.X/2, 0, 0)
local posX = cf.Position.X

if posX > 10 then
print("Rotated part past 10 studs")
else
print("Rotated part within bounds")
end

[OnceCrowned]

Could you check the magnitude?

local cf = part.CFrame
local newPos = part.CFrame * CFrame.new(part.Size.X / 2, 0, 0)
print((cf.p - newPos.p).magnitude)

[KrimsonWoIf (ClassicDev)]

the magnitude appears to be

2.000002145767212

which differs from when it has a rotation of 0 which is

2

If you’re concerned with your equation, I tested it with this code

while true do 
   local part = workspace.Part 
   local newPos = part.CFrame * CFrame.new(part.Size.X / 2, 0, 0)
   part.CFrame = newPos 
   task.wait(.5) 
end

and it appears to be fine. It started moving diagonally.

[OnceCrowned]

Does that matter? You can just math.floor it