I need help debugging something

Help
, ,
1

Hi,

I am trying to remake Minecraft in Core and no matter what I do I can't seem to make it so you can break blocks it just keeps saying the same error every single time. Here is my code:

local BlockTable = require(script:GetCustomProperty('Blocks'))
local WorldGenerator = require(script:GetCustomProperty('WorldGenerator'))

local abilityObject = script.parent

function ConnectAbilityEvents_BreakBlock(ability)
	ability.executeEvent:Connect(OnExecute_BreakBlock)
						
end


function OnExecute_BreakBlock(ability)
	print("OnExecute " .. ability.name)
	local player = ability.owner
	local foward = (player:GetLookWorldRotation() * Vector3.New(300,0,0) + player:GetWorldPosition())
	local hit = World.Raycast(player:GetWorldPosition(), foward, {ignorePlayers = true})
	if hit then
		local hitObject = hit.other
		local blockPos = hitObject:GetWorldPosition() / 100
		local blockTableEntry = _G.Blocks[blockPos.x][blockPos.y][blockPos.z]
		_G.Blocks[blockPos.x][blockPos.y][blockPos.z] = {blockInfo = BlockTable['Air'], isSpawned = true}
		hitObject:Destroy()
		WorldGenerator.SpawnSurroundingBlocks(blockPos.x, blockPos.y, blockPos.z)
	end
	local targetData = ability:GetTargetData()
end

ConnectAbilityEvents_BreakBlock(abilityObject)

and this is the error i get:

Error running Lua task: [88688ACDDD011225] BreakBlockAbility:21: attempt to index a nil value (field '?')

2

Please post your code using </> code tags.

Please post the error message that you get.

4

@RedQuad ok i posted the error and did the </> thing. this is my first time ever using the fourm

5

Hey, no worries.

Looks like the problem is this line (is this the line that is highlighted when you click on the error?):

_G.Blocks[blockPos.x][blockPos.y][blockPos.z] = {blockInfo = BlockTable['Air'], isSpawned = true}

How did you declare _G.Blocks initially? I'm not that great at lua, but I think you would need a little loop to set it up to receive the 3 dimensions like an array:

_G.Blocks = {}
for i=1,10 do
    _G.Blocks[i] = {} 
    for j=1,10 do
        _G.Blocks[i][j] = {}
    end
end

Notice you need to set a size for the first two array dimensions.

If it is not that, are you sure that BlockTable['Air'] is defined? And that the blockPos values are what you expect (try adding some print() commands to check values).

Make sure you are staying within the bounds of the declared array.

6

So when i click on it i get taken to to this line:

local blockTableEntry = _G.Blocks[blockPos.x][blockPos.y][blockPos.z]

also here are the two scripts that are properties of this script:

Blocks:

local blocks = {}

blocks['BasicBlock'] = {template = script:GetCustomProperty('BasicBlock')}
blocks['Dirt'] = {template = script:GetCustomProperty('Dirt')}
blocks['Grass'] = {template = script:GetCustomProperty('Grass')}
blocks['Stone'] = {template = script:GetCustomProperty('Stone')}

blocks['Air'] = {template = nil}

return blocks

WorldGenerator:

local perlinNoise = require(script:GetCustomProperty('PerlinLIB'))
local blockTable = require(script:GetCustomProperty('BlockTable'))

local WorldGenerator = {}

local xStart = 0
local xEnd = 0
local yStart = 0
local yEnd = 0

local maxHeight = 32
local maxDown = -16

local caveScale = 0.08
local caveSpawnRate = -0.3
local entranceSpawnRate = -0.5

function WorldGenerator.Generate(xStartP, xEndP, yStartP, yEndP)

    xStart = xStartP
    xEnd = xEndP
    yStart = yStartP
    yEnd = yEndP

    for x = xStart - 1, xEnd + 1 do
        _G.Blocks[x] = {}
        for y = yStart - 1, yEnd + 1 do
            _G.Blocks[x][y] = {}
            if x < xStart or x > xEnd or y < yStart or y > yEnd then
                for z = maxDown - 1, maxHeight + 1 do
                    if not _G.Blocks[x][y][z] then
                        _G.Blocks[x][y][z] = {blockInfo = blockTable['Air'], isSpawned = true}
                    end
                end
            else
                local height = math.floor(perlinNoise:noise(x,y,0,0.1) * 10)


                for z = maxDown, height do
                    local shouldSpawn = (perlinNoise:noise((x + 999) / 2, (y + 999) / 4, z, caveScale) > caveSpawnRate) and (perlinNoise:noise((x + 999) / 4, (y + 999) / 2, z, caveScale) > caveSpawnRate) and  (perlinNoise:noise((x + 999) / 2, (y + 999) / 2, z / 4, caveScale) > caveSpawnRate)                
                    local shouldSpawnEntrance = (perlinNoise:noise((x + 999) / 2, (y + 999) / 4, z, caveScale) > entranceSpawnRate) and (perlinNoise:noise((x + 999) / 4, (y + 999) / 2, z, caveScale) > entranceSpawnRate) and  (perlinNoise:noise((x + 999) / 2, (y + 999) / 2, z / 4, caveScale) > entranceSpawnRate)

                    if z == height - 1 then
                        if shouldSpawnEntrance then
                            _G.Blocks[x][y][z] = {blockInfo = blockTable['Grass'], isSpawned = false}
                        else
                            _G.Blocks[x][y][z] = {blockInfo = blockTable['Air'], isSpawned = true}
                        end
                    elseif z >= height - 3 then 
                        if shouldSpawnEntrance then
                            _G.Blocks[x][y][z] = {blockInfo = blockTable['Dirt'], isSpawned = false}
                        else
                            _G.Blocks[x][y][z] = {blockInfo = blockTable['Air'], isSpawned = true}
                        end
                
                    elseif z == maxDown then
                        _G.Blocks[x][y][z] = {blockInfo = blockTable['Stone'], isSpawned = false}
                    else
                        if shouldSpawn then
                            _G.Blocks[x][y][z] = {blockInfo = blockTable['Stone'], isSpawned = false}
                        else
                            _G.Blocks[x][y][z] = {blockInfo = blockTable['Air'], isSpawned = true}
                        end
                    end
                end

                for z = height, maxHeight do
                    _G.Blocks[x][y][z] = {blockInfo = blockTable['Air'], isSpawned = true}
                end
            end
            if math.random(1,3) == 1 then
                Task.Wait()
            end
        end
        Task.Wait()
    end
    WorldGenerator.SpawnBlocks()
end



function WorldGenerator.isBlockSurrounded(x,y,z)
    if x == xStart or y == yStart or x == xEnd or y == yEnd or z == maxHeight or z == maxDown then
        return false
    end
    if _G.Blocks[x+1][y][z].blockInfo.template == nil then
        return false
    elseif _G.Blocks[x-1][y][z].blockInfo.template == nil then
        return false
    elseif _G.Blocks[x][y+1][z].blockInfo.template == nil then
        return false
    elseif _G.Blocks[x][y-1][z].blockInfo.template == nil then
        return false
    elseif _G.Blocks[x][y][z+1].blockInfo.template == nil then
        return false
    elseif _G.Blocks[x][y][z-1].blockInfo.template == nil then
        return false
    end
    return true
end

function WorldGenerator.SpawnSurroundingBlocks(x,y,z)
    if _G.Blocks[x+1][y][z].blockInfo.template ~= nil and not _G.Blocks[x+1][y][z].isSpawned then
        WorldGenerator.SpawnBlock(x+1,y,z,_G.Blocks[x+1][y][z].blockInfo.template)
    end
    if _G.Blocks[x-1][y][z].blockInfo.template ~= nil and not _G.Blocks[x-1][y][z].isSpawned then
        WorldGenerator.SpawnBlock(x-1,y,z,_G.Blocks[x-1][y][z].blockInfo.template)
    end
    if _G.Blocks[x][y+1][z].blockInfo.template ~= nil and not _G.Blocks[x][y+1][z].isSpawned then
        WorldGenerator.SpawnBlock(x,y+1,z,_G.Blocks[x][y+1][z].blockInfo.template)
    end
    if _G.Blocks[x][y-1][z].blockInfo.template ~= nil and not _G.Blocks[x][y-1][z].isSpawned then
        WorldGenerator.SpawnBlock(x,y-1,z,_G.Blocks[x][y-1][z].blockInfo.template)
    end
    if _G.Blocks[x][y][z+1].blockInfo.template ~= nil and not _G.Blocks[x][y][z+1].isSpawned then
        WorldGenerator.SpawnBlock(x,y,z+1,_G.Blocks[x][y][z+1].blockInfo.template)
    end
    if _G.Blocks[x][y][z-1].blockInfo.template ~= nil and not _G.Blocks[x][y][z-1].isSpawned then
        WorldGenerator.SpawnBlock(x,y,z-1,_G.Blocks[x][y][z-1].blockInfo.template)
    end
end


function WorldGenerator.SpawnBlocks()
    for x = xStart, xEnd do
        for y = yStart, yEnd do
            for z = maxDown, maxHeight do
                if not WorldGenerator.isBlockSurrounded(x,y,z) then
                    if _G.Blocks[x][y][z].blockInfo.template ~= nil then
                        WorldGenerator.SpawnBlock(x,y,z,_G.Blocks[x][y][z].blockInfo.template)
                    end
                end
            end
        end
        Task.Wait()
    end
end

function WorldGenerator.SpawnBlock(x,y,z,block)
    local block = World.SpawnAsset(block, {position = Vector3.New(x,y,z) * 100})
    _G.Blocks[x][y][z].isSpawned = true
end

return WorldGenerator
7

OK, so if you print() blockPos.x / y / z on the line before that do you actually get some reasonable values? I think the most likely cause of error is that those values do not point to an existing value in the _G.Blocks table. I would try looping through the _G.Blocks table to see what is defined in it near the index values that you are interested in.

It seems to me a risky strategy to be using the floats from a world position vector directly to index a lua table. But that's just my opinion.

8

so when i print blockPos it shows the actual position so there is no nil so idk why it's giving me a nil error

9

so i tested it for a bit and apparently sometimes the script works, and sometimes it errors

10

nvm i fixed myself