local part = Instance.new("Part", workspace)
local size = part.Size
local region3 = Region3.new(part.Position - (size / 2), part.Position + (size / 2))
--[[
makes a new part and sets it's parent to the workspace
your part MUST have an Orientation of (0, 0, 0) and be a cube shape if you want
it's region to correspond to it's appearance in workspace
]]