How do I get the world position of a frame in surface gui given object rotation?

ZER0PSS · July 20, 2022, 10:14am

I have a script that creates a SurfaceGui with N/A number of frames vertically and horizontally, how do I get their world position?

McThor2 · July 20, 2022, 11:42am

I think you just need this method - Camera | Roblox Creator Documentation

ZER0PSS · July 20, 2022, 11:53am

I almost got it by this code:

local Part = self.surface
	local Side = self.gui.Face
	local TopLeft = CFrame.new()
	
	if Side == Enum.NormalId.Front then
		TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,-Part.Size.Z/2)
	elseif Side == Enum.NormalId.Back then
		TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2)
	elseif Side == Enum.NormalId.Left then
		TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,-Part.Size.Z/2)
	elseif Side == Enum.NormalId.Right then
		TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2)
	end
	
	
	
	local TopLeftPosition = TopLeft.Position
	TopLeftPosition = Vector3.new(TopLeftPosition.x / 2, TopLeftPosition.y / 2, TopLeftPosition.z / 2)
	
	for x=0, self.resolution.x-1 do
		for y=0, self.resolution.y-1 do
			if self.pixels[tostring(x) + tostring(y)] then
				local world_vector = self.pixels[tostring(x) + tostring(y)].world_vector
				local frame = self.pixels[tostring(x) + tostring(y)][tostring(x) + tostring(y)]
				
				world_vector.Value = TopLeftPosition + Vector3.new((self.surface.size.x * x)/2, (self.surface.size.y * y)/2, TopLeftPosition.z)
				
				local p = Instance.new("Part", workspace)
				p.Anchored = true
				p.Size = Vector3.new(0.1, 0.1, 0.1)
				p.Position = world_vector.Value
			end
		end
	end

but it still make it wrong

McThor2 · July 20, 2022, 12:20pm

Ah my bad I read SurfaceGui as ScreenGui somehow.

local Part = self.surface
local Side = self.gui.Face
local TopLeft = CFrame.new()
local width = 0
local height = 0

-- Use CFrame.Angles to orient the TopLeft CFrame such that TopLeft.rightVector is in the x direction of the surface gui and -TopLeft.upVector is in the y direction of the surface gui
if Side == Enum.NormalId.Front then
	TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) * CFrame.Angles(0, math.rad(180), 0)
	width = Part.Size.X
	height = Part.Size.Y
elseif Side == Enum.NormalId.Back then
	TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,-Part.Size.Z/2)
	width = Part.Size.X
	height = Part.Size.Y 
elseif Side == Enum.NormalId.Left then
	TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) * CFrame.Angles(0, 0, math.rad(-90) )
	width = Part.Size.Z
	height = Part.Size.Y 
elseif Side == Enum.NormalId.Right then
	TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) * CFrame.Angles(0, math.rad(90), 0)
	width = Part.Size.Z
	height = Part.Size.Y 
end

for x=0, self.resolution.x-1 do
	for y=0, self.resolution.y-1 do
		if self.pixels[tostring(x) + tostring(y)] then
			local world_vector = self.pixels[tostring(x) + tostring(y)].world_vector
			local frame = self.pixels[tostring(x) + tostring(y)][tostring(x) + tostring(y)]
			
			-- Use the TopLeft CFrame to get the world position
			world_vector.Value = TopLeft.Position + ( TopLeft.RightVector * x / self.resolution.x * width - TopLeft.UpVector * y / self.resolution.y * height)
			
			local p = Instance.new("Part", workspace)
			p.Anchored = true
			p.Size = Vector3.new(0.1, 0.1, 0.1)
			p.Position = world_vector.Value
		end
	end
end

ZER0PSS · July 20, 2022, 12:40pm

This works but it’s on the wrong side when it should be on NormalId Front it’s on Back

ZER0PSS · July 20, 2022, 12:42pm

Like this: Frames on front, and the points on back

ZER0PSS · July 20, 2022, 12:50pm

works perfectly, swapped back and front

McThor2 · July 20, 2022, 12:51pm

Ah I must have got the Enums mixed up but it seems like you’ve fixed it now

ZER0PSS · July 20, 2022, 12:55pm

yep, thanks, you just helped me alot < 3

ZER0PSS · July 20, 2022, 7:14pm

Im sorry but can you help me with coe again? I make it to use pixel by pixel and now i using

function pixel:update(surface, face, resolution)
	local Part = surface
	local Side = face
	local TopLeft = CFrame.new()
	local width = 0
	local height = 0

	-- Use CFrame.Angles to orient the TopLeft CFrame such that TopLeft.rightVector is in the x direction of the surface gui and -TopLeft.upVector is in the y direction of the surface gui
	if Side == Enum.NormalId.Front then
		TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,-Part.Size.Z/2)
		width = Part.Size.X
		height = Part.Size.Y
	elseif Side == Enum.NormalId.Back then
		TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) * CFrame.Angles(0, math.rad(180), 0)
		width = Part.Size.X
		height = Part.Size.Y
	elseif Side == Enum.NormalId.Left then
		TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) * CFrame.Angles(0, 0, math.rad(-90) )
		width = Part.Size.Z
		height = Part.Size.Y 
	elseif Side == Enum.NormalId.Right then
		TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) * CFrame.Angles(0, math.rad(90), 0)
		width = Part.Size.Z
		height = Part.Size.Y 
	end
	
	local position = self.instance.AbsolutePosition
	print(position)
	
	self.world_position = TopLeft.Position + ( TopLeft.RightVector * position.x / resolution.x * width - TopLeft.UpVector * position.y / resolution.y * height)
	
	local p = Instance.new("Part", workspace)
	p.Anchored = true
	p.Size = Vector3.new(0.1, 0.1, 0.1)
	p.Position = self.world_position
end

but that doesn’t work, pls help if you can

McThor2 · July 20, 2022, 7:22pm

What is wrong with it/ what issue are you having?

ZER0PSS · July 21, 2022, 5:28am

It arranges the vectors incorrectly, most likely this is due to the lack of a for loop, because I am addressing the pixel directly

McThor2 · July 21, 2022, 9:51am

Is this something like a frame directly parented to the surface gui then?

ZER0PSS · July 21, 2022, 10:49am

yep, thats it, i need three characters
to reply

McThor2 · July 21, 2022, 11:55am

I think the rearrangement of front to back hasn’t been done properly maybe then. I reckon it should be this

if Side == Enum.NormalId.Front then
	TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,-Part.Size.Z/2) * CFrame.Angles(0, math.rad(180), 0)
	width = Part.Size.X
	height = Part.Size.Y
elseif Side == Enum.NormalId.Back then
	TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) 
	width = Part.Size.X
	height = Part.Size.Y

ZER0PSS · July 22, 2022, 7:18am

McThor2:

if Side == Enum.NormalId.Front then
	TopLeft = Part.CFrame * CFrame.new(Part.Size.X/2,Part.Size.Y/2,-Part.Size.Z/2) * CFrame.Angles(0, math.rad(180), 0)
	width = Part.Size.X
	height = Part.Size.Y
elseif Side == Enum.NormalId.Back then
	TopLeft = Part.CFrame * CFrame.new(-Part.Size.X/2,Part.Size.Y/2,Part.Size.Z/2) 
	width = Part.Size.X
	height = Part.Size.Y

that doesn’t helped, yet, it still very big distance…

McThor2 · July 22, 2022, 10:06am

What are you passing in for the resolution?

ZER0PSS · July 22, 2022, 1:23pm

literally nothing because the method is in pixel

McThor2 · July 22, 2022, 3:01pm

You need to pass in the resolution (in pixels) of the surface gui in order for it to work.