Get closest direction to a vector

[dani_lionn (daniella)]

I have a weather app on an in game phone in my game and I want it to display what direction the GlobalWind is blowing (north, south, east, west).

These are my directions:

		local directions = {
			{Direction = Vector3.new(1,0,0), Name = "East"},
			{Direction = Vector3.new(-1,0,0), Name = "West"},
			{Direction = Vector3.new(0,0,1), Name = "South"},
			{Direction = Vector3.new(0,0,-1), Name = "North"},
			{Direction = Vector3.new(1,0,-1), Name = "Northeast"},
			{Direction = Vector3.new(-1,0,-1), Name = "Northwest"},
			{Direction = Vector3.new(1,0,1), Name = "Southeast"},
			{Direction = Vector3.new(-1,0,1), Name = "Southwest"},
		}

How can I find the direction closest to what GlobalWind currently is?

[Uhsleep91]

It might not be the most efficient, but you can dot GlobalWind with each of the direction vectors and choose the vector that resulted in the highest value.

[MayorGnarwhal (Gnarwhal)]

If you take the dot product of two unit vectors, 1 means they are in the same direction, -1 means they are in the opposite direction, and 0 means they are perpendicular. Using this, given any vector the closest direction will be the one with the highest dot product (when normalizing the vectors).

local function GetDirection(vector)
	vector = vector.Unit
	
	local matchingDirection
	local maxProduct = -math.huge
	
	for i, direction in pairs(directions) do
		local product = vector:Dot(direction.Direction.Unit)
		if product > maxProduct then
			maxProduct = product
			matchingDirection = direction
		end
	end
	
	return matchingDirection
end

local vector = Vector3.new(1, 0, 0.1)
local direction = GetDirection(vector)
print(direction.Name) -- "East"

[dani_lionn (daniella)]

Thank you!

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