Trouble with WorldToViewportPoint

Help and Feedback Scripting Support
,
#1

Hey, I am having a bit of trouble with the WorldToViewportPoint function of the camera.
I want to be able to move the camera around a model and have a red square over the
same part no matter how much i rotate the model. Currently it doesn’t position the
red box where i want it to and i don’t know if this is something that i am doing wrong
or if its a mistake with the function

Here is the code

function PositionPointer()
	local Vector, OnScreen = Cam:WorldToViewportPoint(Scene.Level2.Window1.Position)
	Pointer.Position = UDim2.new(Vector.X,0, Vector.Y, 0)
end

function UpdateCamPos()	
	Cam.CFrame = Scene.Plot1.CFrame 
		* CFrame.fromEulerAnglesYXZ(math.rad(LastRot.Y), math.rad(-LastRot.X), 0)
		* CFrame.new(0, 3, Distance)
	PositionPointer()
end

Here is a picture that shows where i want the marker to be compared to where it is
(I want the red frame in the center the blue part)
image

Here is the current layout plus the Properties
image
ViewportFrame:

image
image385×713 12.7 KB

Pointer/red box:
image
image370×575 7.98 KB

Please ask if there is more information you need.

1 Like
#2

I had the very same issue when trying to use these methods inside a ViewportFrame, and to my knowledge, after multiple attempts at solving the problem, you simply cannot use these methods in a viewportframe. It’s like their functionality breaks down once you try to use them outside of workspace

3 Likes
#3

Well damn, thats a bit of a bummer. I will try to make some custom system then, but thank you for the reply.

2 Likes
#4

Your reply sparked an idea in my mind, it is a bit hacky bit it works like i want it to.

Steps:
1. Get the offset from the camera to the part in the viewport
2. Translate that to a world position using the current cam
3. Do the worldToViewportPoint with the new world position and currentcamera

function PositionPointer()
	local Offset = Cam.CFrame:PointToObjectSpace(Scene.Level2.Window1.Position)
	local WorldSpace = CurrentCam.CFrame:PointToWorldSpace(Offset)
	local Vector, OnScreen = CurrentCam:WorldToViewportPoint(WorldSpace)
	Pointer.Position = UDim2.new(0,Vector.X, 0, Vector.Y)
end

function UpdateCamPos()	
	Cam.CFrame = Scene.Plot1.CFrame 
		* CFrame.fromEulerAnglesYXZ(math.rad(LastRot.Y), math.rad(-LastRot.X), 0)
		* CFrame.new(0, 3, Distance)
	PositionPointer()
end

ps i have to do some more calculations if i want to use another viewport size

2 Likes