What is the appropriate equations for smashable glass?

So here is what I've stuck together, and has some ALRIGHT results, looking like this: https://gyazo.com/f7a370680579f3669a9522db4e2a6e1a

The bits in front are products of the script, and the bit behind is a replica of the part that was converted

local event = game.ReplicatedStorage.Remotes.Weapon.Smash

function event.OnServerInvoke(plr, objHit)
	--MATHS
	local size = objHit.Size
	local centerpos = objHit.Position
	local width = size.X / 3
	local hight = size.Y / 3
	local x1 = centerpos.X * 2
	local x2 = x1 / 3
	local y = centerpos.Y * 2
	local y2 = y / 3
	local position = Vector3.new(x2, y2, centerpos.Z)
	local sizenew = Vector3.new(width / 3, hight / 3, size.Z)
	local positions = {{position.X, position.Y, position.Z}, {position.X + width, position.Y, position.Z}, {position.X + (width * 2), position.Y, position.Z}--//Firstline--//
					, {position.X, position.Y - hight, position.Z}, {position.X +  width, position.Y - hight, position.Z}, {position.X + (width * 2), position.Y - hight, position.Z},--//Secondline--//
					  {position.X, position.Y - (hight*2), position.Z}, {position.X +  width, position.Y - (hight*2), position.Z}, {position.X + (width * 2), position.Y - (hight*2), position.Z}}--//Thirdline//--
	--Generate
	objHit.CanCollide = false
	local i = 1
	while i <= 9 do
		local pos = positions[i]
		local shard = Instance.new("Part", workspace)
		shard.Transparency = objHit.Transparency
		shard.Reflectance = objHit.Transparency
		shard.Anchored = false
		shard.CanCollide = true
		shard.FormFactor = Enum.FormFactor.Custom
		shard.Name = "Glass"
		shard.Position = Vector3.new(pos[1], pos[2], pos[3])
		shard.Size = sizenew
		shard.Anchored = true
		i = i + 1
	end
	objHit.Transparency = 1

	
	
end

local event = game.ReplicatedStorage.Remotes.Weapon.Smash

function event.OnServerInvoke(plr, objHit)
	--MATHS
	local size = objHit.Size
	local originalpos = objHit.Position
	local orix = size.X
	local oriy = size.Y
	local oriz = size.Z
	local x = orix / 3
	local y = oriy / 3
	local z = oriz
	local x1 = originalpos.X
	local x2 = x1 - x
	local y1 = originalpos.Y
	local y2 = y1 - y
	local z1 = originalpos.Z
	local positions = {
		Vector3.new(x2, y2, z1), Vector3.new(x2 + x, y2, z1), Vector3.new(x2 + (2 * x), y2, z1),
		Vector3.new(x2, y1, z1), Vector3.new(x2 + x, y1, z1), Vector3.new(x2 + (2 * x), y1, z1),
		Vector3.new(x2, y1 + y, z1), Vector3.new(x2 + x, y1 + y, z1), Vector3.new(x2 + (2 * x), y1 + y, z1),
	}
	local i = 1
	while i <= 9 do
		wait()
		local Part = Instance.new('Part', game.Workspace)
		Part.Anchored = true
		Part.Position = positions[i]
		Part.CanCollide = false
		Part.BrickColor = BrickColor.new'Teal'
		Part.Transparency = 0.7
		Part.Size = Vector3.new(x, y, z)
		i = i + 1
	end
end

x1 and y1 represent the center and since it is a 3 by 3 you do some algebra to get this

There's a smashable glass thing as a model in the toolbox, probably some kind of formula in there