About CFrame.new (Vector3 pos, Vector3 lookAt) documentation on the hub

loleris · May 6, 2020, 4:33pm

I’ve recently discovered an addition to CFrame documentation under
CFrame.new(Vector3 pos, Vector3 lookAt) constructor:

This constructor has been deprecated in favor of using `CFrame.fromMatrix(), to create a lookVector

It seems really strange to have this constructor deprecated in favor of a constructor that takes matrix values to construct a CFrame, since it seems like performing the necessary math on Lua takes quite a bit more time:


local v1 = Vector3.new(1.1, 1.2, 1.3)
local v2 = Vector3.new(0.75, 5.8, 6)

function lookAt(target, eye)
    local forwardVector = (target - eye).Unit
    local upVector = Vector3.new(0, 1, 0)
    -- You have to remember the right hand rule or google search to get this right
    local rightVector = forwardVector:Cross(upVector)
    local upVector2 = rightVector:Cross(forwardVector)
 
    return CFrame.fromMatrix(eye, rightVector, upVector2)
end


local t1 = tick()

for i = 1, 1000000 do
	local x = CFrame.new(v1, v2)
end

print(tick() - t1)

local t2 = tick()

for i = 1, 1000000 do
	local x = lookAt(v2, v1)
end

print(tick() - t2)

Output:

0.12635779380798
0.49749302864075

Is this intentional? I’m pretty confused lol

Link to CFrame documentation: