砖块生成脚本Y轴位置指数异常的原因问询（已解决）

我写了个用来生成大量砖块的脚本，原本是给可破坏场景（比如箭靶场）做基础的。一开始砖块尺寸是2x2x2，后来为了优化性能改成4x4x4，结果改完之后脚本在Y轴方向出现了指数级的位置异常。

原脚本代码：

-- Origin == {POS = 0,0,0; SIZE = 4,4,4}
-- Finality == {POS == -477, 2, 243; SIZE = 4,4,4}

local location   =   {X = script.Origin.Position.X, 
                  Y = script.Origin.Position.Y, 
                  Ymoved = script.Origin.Position.Y,
                  Z = script.Origin.Position.Z}
--[[Previously Ymoved started at Origin.Position and went up how many tiles we went per floor.]]


local MATZ          = {"Marble","Ice"}
local Colours       = {Color3.new(0.25, 0.25, 0.25),Color3.new(0.811765, 0.992157, 1)}
local locationEnd   = script.Finality.Position
local count             = 0

local Vector = Vector3.new

while true do
    local brick = Instance.new("Part", game.Workspace)

        --Main Part creation
    brick.Name          = "Brick_"..count
    brick.Position      = Vector(location.X, location.Y, location.Z)
    brick.Size          = Vector(4,4,4)
    brick.Anchored      = true

        --Prettify (needs more options)
    local SEED          = math.random(1,2)
    brick.Material      = MATZ[SEED]
    brick.Color         = Colours[SEED]
    
    if location == locationEnd then 
                --unsafe, needs to be changed once i actually have an endpoint...
        break
    
    elseif location.X >= locationEnd.X then
        location.X = script.Origin.Position.X
        location.Z = location.Z - 4
        print("Next column")

    elseif location.Z <= locationEnd.Z then
        location.X = script.Origin.Position.X
        location.Z = script.Origin.Position.Z

                location.Ymoved = location.Ymoved + 2
        location.Y = script.Origin.Position.Y + location.Ymoved    --This line is antibepis
        print("Next floor")
    end
    
    if count % 250 == 0 then
        wait()
    end
    

    location.X = location.X + 4
    count = count + 1
end

排查后发现问题出在Y轴的位置更新逻辑上，先看两种错误写法的问题：
第一种写法会导致砖块在Y轴指数级靠拢：

location.Ymoved = location.Ymoved + 2
location.Y = script.Origin.Position.Y + location.Ymoved

改成第二种写法后，每层砖块又会指数级远离：

location.Ymoved = location.Ymoved + 2
location.Y = location.Y + location.Ymoved

最后用直接的写法解决了问题：

location.Y = location.Y + 4

为什么会出现指数级异常？ #

• 第一种写法的问题：
  Ymoved初始值是原点Y坐标（假设为0），每次触发换楼层逻辑时，Ymoved都会累加2。但脚本中换楼层的判断条件location.Z <= locationEnd.Z可能在循环中被多次触发（比如Z轴位置未正确复位时），导致Ymoved被反复累加，增长速度从预期的线性变成了触发次数的累加，最终形成指数级增长，Y轴位置自然出现异常靠拢。

• 第二种写法的问题：
  改成location.Y = location.Y + location.Ymoved后，Y轴的增量是当前的Ymoved值，而Ymoved本身一直在累加。比如第一次换楼层时Ymoved=2，Y从0变成2；第二次Ymoved=4，Y变成2+4=6；第三次Ymoved=6，Y变成6+6=12……这种“增量本身不断变大”的逻辑，会让Y轴的增长变成累加的累加，也就是二次增长，视觉上就呈现出指数级远离的效果。

为什么2x2x2尺寸时没这个问题？ #

一是原来的尺寸下，对应的Y轴增量（比如每次加1）和触发条件刚好匹配，换楼层的逻辑不会被多次触发，Ymoved的累加处于可控状态；二是2x2x2的尺寸很小，即使有微小的累加异常，视觉上也不容易察觉，改成4x4x4后，每次增量变成2，异常被放大，就明显表现出来了。

内容的提问来源于stack exchange，提问作者Link_jon