Post your modding questions here

[Godo]

Thank you very much, it works all right with version 0.4.14 (I thought it was only a developer's version, so I had not tried it).

[Thegameboy]

Topic: Is there any update function?
Reason: Update function to place code in that updates every tick/frame, to continually check certain conditions? Also, for something like...

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Code: Select all

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  local y = pos.y
end)

...how do you get the local (or global, could be any kind really) variable outside of the function's local environment and into the script's? The script is loaded when the world starts up but the callback is executed at a later point in time...

More Info: I've checked for a bit for answers to these questions on the glossary for functions but couldn't find anything that applies.

[sofar]

Topic: Is there any update function?
Reason: Update function to place code in that updates every tick/frame, to continually check certain conditions? Also, for something like...

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  local y = pos.y
end)

...how do you get the local (or global, could be any kind really) variable outside of the function's local environment and into the script's? The script is loaded when the world starts up but the callback is executed at a later point in time...

More Info: I've checked for a bit for answers to these questions on the glossary for functions but couldn't find anything that applies.

Short answer: make a persistent variable outside the `register_on_joinplayer()` function:

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Code: Select all


local storage = {}

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  storage.y = pos.y
end)



[rubenwardy]

Topic: Is there any update function?
Reason: Update function to place code in that updates every tick/frame, to continually check certain conditions? Also, for something like...

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  local y = pos.y
end)

...how do you get the local (or global, could be any kind really) variable outside of the function's local environment and into the script's? The script is loaded when the world starts up but the callback is executed at a later point in time...

More Info: I've checked for a bit for answers to these questions on the glossary for functions but couldn't find anything that applies.

Short answer: make a persistent variable outside the `register_on_joinplayer()` function:

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all


local storage = {}

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  storage.y = pos.y
end)



That'll only work for a single player, much better is:

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Code: Select all

local storage = {}

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  storage[player:get_player_name()] = {y = pos.y}
end)

minetest.register_on_leaveplayer(function(player)
  storage[player:get_player_name()] = nil
end)

local function checkSomething(player)
  local pos = storage[player:get_player_name()]
  print(pos.y)
end


to run code every X seconds, the best way is to use minetest.after:

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Code: Select all

local function timerRun()
    -- code to run

    minetest.after(X, timerRun)
end

minetest.after(X, timerRun)


Replace X with a number, whole ones work best.

To run every X seconds on a node, use ABMs or a nodetimer.

[TumeniNodes]

So, I am almost finished with my texture pack, and plan to make it available soon. (within about 2 weeks to a month)
But I have a roadblock to consider and resolve.
Some of the textures in the pack will rely upon some minor alterations to the default nodes lua (regarding default water source), and the default mapgen... How best to approach this?
Do I release the TP as mod, rather than simply a TP? And if so, what is the best way to do so?, as I will want the TP textures to over ride the default textures (which is simple in itself), but it also adds a few textures which then require my alterations to the default mapgen (where I added "Red_Desert" and "Red_Desert_Ocean" biomes)
Just looking for some input, thoughts & advice. Thank you

wow, feel like this got the cold shoulder... oh well 4 days later no response

[Thegameboy]

. . .

Short answer: make a persistent variable outside the `register_on_joinplayer()` function:

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Code: Select all


local storage = {}

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  storage.y = pos.y
end)



That'll only work for a single player, much better is:

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

local storage = {}

minetest.register_on_joinplayer(function(player) --player object
  local pos = player:getpos()
  storage[player:get_player_name()] = {y = pos.y}
end)

minetest.register_on_leaveplayer(function(player)
  storage[player:get_player_name()] = nil
end)

local function checkSomething(player)
  local pos = storage[player:get_player_name()]
  print(pos.y)
end


to run code every X seconds, the best way is to use minetest.after:

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

local function timerRun()
    -- code to run

    minetest.after(X, timerRun)
end

minetest.after(X, timerRun)


Replace X with a number, whole ones work best.

To run every X seconds on a node, use ABMs or a nodetimer.

Thanks a lot, guys!

[pithy]

How do I count how many nodes are near a node?

[pithy]

and can I make an ABM do one action on all loaded nodes, and then the other action?

[sofar]

How do I count how many nodes are near a node?

Ambiguous, even "air" is a node, so you need to be more specific.

If you want to count specific nodes, you can use e.g.

https://github.com/minetest/minetest/bl ... .txt#L2033

the return value is an array, so you can count the items in it with #arrayname.

[AnxiousInfusion]

to run code every X seconds, the best way is to use minetest.after:

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Code: Select all

local function timerRun()
    -- code to run

    minetest.after(X, timerRun)
end

minetest.after(X, timerRun)


Replace X with a number, whole ones work best.

Interesting, in making my first timer I wanted to use minetest.after in that way but I was afraid it would hit a recursion limit after continuously calling the function from within itself for long enough. Does lua not suffer from this problem? Regardless, I ended up using minetest.register_globalstep to serve that purpose.

[kaeza]

Interesting, in making my first timer I wanted to use minetest.after in that way but I was afraid it would hit a recursion limit after continuously calling the function from within itself for long enough. Does lua not suffer from this problem? Regardless, I ended up using minetest.register_globalstep to serve that purpose.

It isn't a recursive call. You just "push" or "queue" a function to be called later. At the time the next call to your function actually happens, the original call to your function already returned (regardless of the `after` timeout).

[sofar]

to run code every X seconds, the best way is to use minetest.after:

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

local function timerRun()
    -- code to run

    minetest.after(X, timerRun)
end

minetest.after(X, timerRun)


Replace X with a number, whole ones work best.

Interesting, in making my first timer I wanted to use minetest.after in that way but I was afraid it would hit a recursion limit after continuously calling the function from within itself for long enough. Does lua not suffer from this problem? Regardless, I ended up using minetest.register_globalstep to serve that purpose.

This is safe.

Timers that are inserted during the execution of timers are not executed until the next global step ever.

This is done explicitly to allow this usage and to make it safe.

The way it works in detail is that if timers are added to the list of timers, they will never be processed in the current timer execution cycle, because the timer execution code goes from the BACK of the table to the front, and so it will not see new timers until it runs again at a later time.

Please use this minetest.after() "recursion" instead of globalstep if you don't need to be running every globalstep!

[rubenwardy]

It doesn't call itself from within itself. It adds the function onto a priority queue to be run again

[pithy]

How do I search for a node in all loaded blocks?

[Hybrid Dog]

How do I search for a node in all loaded blocks?

You could use lbm to catch specific nodes when they get loaded.

[Sirmentio]

How do I make a sound play (with minetest.sound_play) for an entire multiplayer server?

My friend has been getting an error in the logs and were not sure if it's possible:

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Code: Select all

Undeclared global variable "playedmus" accessed at init.lua (Line 14)"
"Assignment to undeclared global "playedmus" inside a function at init.lua (Line 17)

[ErrorNull]

hello everyone. i have two modding questions:

#1. how can i replicate the on-screen effect of flashing color when something happens to the player? ex. I've made a mod that incorporates player exhaustion states.. and would like the screen to flash different color like white when player is exhausted. would this be done via huds? if there is existing mod as an example, I'd be happy to learn from that.

I know that i can fake the effect by reducing the player's hp by 1 and giving it back. But i don't want to hinge my effect up the back of an existing (and important) mechanism like the player's health. Plus i want to control the color the of the flashing.

#2. i want to pretty particle effects shower over the player upon consumption of some magic potions... because, you know... all potions have to do that right?! can someone direct me to api or mod example on how to do this... or even some basics on how to call particles into minetest? thanks!

[sofar]

hello everyone. i have two modding questions:

#1. how can i replicate the on-screen effect of flashing color when something happens to the player? ex. I've made a mod that incorporates player exhaustion states.. and would like the screen to flash different color like white when player is exhausted. would this be done via huds? if there is existing mod as an example, I'd be happy to learn from that.

I know that i can fake the effect by reducing the player's hp by 1 and giving it back. But i don't want to hinge my effect up the back of an existing (and important) mechanism like the player's health. Plus i want to control the color the of the flashing.

Make a HUD element that is fullscreen and contains a semi-transparent texture.

#2. i want to pretty particle effects shower over the player upon consumption of some magic potions... because, you know... all potions have to do that right?! can someone direct me to api or mod example on how to do this... or even some basics on how to call particles into minetest? thanks!

read the entire section from here:

https://github.com/minetest/minetest/blob/master/doc/lua_api.txt#L2298

[sofar]

How do I make a sound play (with minetest.sound_play) for an entire multiplayer server?

For every player on the server, play a sound exclusively to that player.

My friend has been getting an error in the logs and were not sure if it's possible:

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

Undeclared global variable "playedmus" accessed at init.lua (Line 14)"
"Assignment to undeclared global "playedmus" inside a function at init.lua (Line 17)

put `local` in front of the place where `playedmus` is first defined or used.

[swordpaint12]

A HUD question. Suppose I wanted to change the hud at certain times so that a certain picture would be on the screen for an amount of time. Kind of like the bubbles. How would I do that? Thanks!

[kaeza]

A HUD question. Suppose I wanted to change the hud at certain times so that a certain picture would be on the screen for an amount of time. Kind of like the bubbles. How would I do that? Thanks!

The function `player:hud_add` returns the ID of the HUD item. Save that somewhere, then just call `player:hud_change(id, "someparam", somevalue)`. See the function's description in `lua_api.txt`.

[swordpaint12]

Thank you!
Okay, new question. In the default mod in the minetest_game, which .lua file contains all the coding for the apple? I want to figure out how you put it down.

[KCoombes]

Hopefully a quick question:

I am trying to edit the default farming mod to add a new crop. I have register_plant and register_craftitem for the crop in the init file, and I can plant the seed and watch the crop grow - but there is no drop when I harvest it. According to the commented init file, the register_craftitem is for registering the harvest - so why is it not dropping the item?

[swordpaint12]

Hopefully a quick question:

I am trying to edit the default farming mod to add a new crop. I have register_plant and register_craftitem for the crop in the init file, and I can plant the seed and watch the crop grow - but there is no drop when I harvest it. According to the commented init file, the register_craftitem is for registering the harvest - so why is it not dropping the item?

Did you code the line that says drop item?

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Code: Select all

drop = "farming:example_food"

I don't know if that would help.

[Sirmentio]

Hopefully this can be easy to understand:

on mobs redo, how could I m,ake an event/function occur upon the mob being punched? Aswell as this, how could I make an event occur when the mob spawns? Thank you in advance

Edit: one more thing (I PROMISE!) is it possible to do an event onjce the mob is down certain health?

[TenPlus1]

Using the do_custom function within the mob definition gives you a lot of freedom when creating customised features, e.g.

when Evil Bonny is spawned into the world it displays a message in chat only once:

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Code: Select all

do_custom = function(self)
   if not self.evil_bonny then
      minetest.chat_send_all(">>> Evil Bonny has been unleashed on this world <<<")
      self.evil_bonny = 1
   end
end,

...or... if health is at a certain level then it shows a message:

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Code: Select all

do_custom = function(self)
   if self.health <= 10 then
      minetest.chat_send_all("Mob health is kinda low, play nice now")
   end
end,

[Sirmentio]

Thanks! I'm very grateful, the context here is that I'm trying to create a boss event for a private server with my friends, now thinking ab out it, is it possible with this to get this theoretical evil bunny's position? Thank you in advance!

[pithy]

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Code: Select all

   on_rightclick = function(pos, node, puncher)
      local nodes = {}
      do
         local start = minetest.find_nodes_in_area({x = pos.x - 1, y = pos.y - 1, z = pos.z - 1}, {x = pos.x + 1, y = pos.y + 1, z = pos.z + 1}, {"group:wireworld"})
         for k,v in pairs(start) do
            table.insert(nodes, v)
         end
      end
      local total = {}
      for k,v in pairs(nodes) do table.insert(total, v) end
      repeat
         local next = {}
         for k,v in pairs(nodes) do
            local find = minetest.find_nodes_in_area({x = v.x - 1, y = v.y - 1, z = v.z - 1}, {x = v.x + 1, y = v.y + 1, z = v.z + 1}, {"group:wireworld"})
            for k,v in pairs(find) do
          if not table.contains(total, v) then
                 local meta = minetest.get_meta(v)
                 table.insert(next, v)
          end
            end
         end
         local nodes = {}
         for k,v in pairs(next) do table.insert(nodes, v) end
         for k,v in pairs(nodes) do table.insert(total, v) end
         local count = 0
         for _ in pairs(nodes) do count = count + 1 end
      until count == 0
      for k,v in pairs(total) do
         local meta = minetest.get_meta(v)
         meta:set_string("wireworld", "stop")
      end
    minetest.swap_node(pos, {name = "wireworld:wireworld_off"})
   end,

This freezes the game every time and I don't know why.
My suspicion is count never reaches 0.

[pithy]

I simplified it to this but it still does the same thing

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Code: Select all

   on_rightclick = function(pos, node, puncher)
      local nodes = minetest.find_nodes_in_area({x = pos.x - 1, y = pos.y - 1, z = pos.z - 1}, {x = pos.x + 1, y = pos.y + 1, z = pos.z + 1}, {"group:wireworld"})
      for i,v in ipairs(nodes) do
         local find = minetest.find_nodes_in_area({x = v.x - 1, y = v.y - 1, z = v.z - 1}, {x = v.x + 1, y = v.y + 1, z = v.z + 1}, {"group:wireworld"})
         for i,v in ipairs(find) do
        if not table.contains(nodes, v) then
              local meta = minetest.get_meta(v)
          meta:set_string("wireworld", "stop")
              nodes[#nodes+1] = v
        end
         end
      end
    minetest.swap_node(pos, {name = "wireworld:wireworld_off"})
   end,

and the table.contains function is

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Code: Select all

function table.contains(table, element)
  for _, value in pairs(table) do
    if value == element then
      return true
    end
  end
  return false
end

[pithy]

to late my brain figured it out