Post your modding questions here

[DeepGaze]

I wish to make a Teleprompter of this concept: a command-controlled value decides weather the player lands at point one or point two but both points land you at base. for clarification see the image below

[Achilles]

Nice Idea, but doesn't the Teleporter mod do more or less that, only you have to type in the coords of the position you wish to teleport to rather than place some sort of Teleporter receiver there...

[DeepGaze]

no I was meaning an automatic switch without having to mention the way each time. making a seamless transition

[lag01]

hope it helps.

Thank you, it helps!

[rubberduck]

question: is there a fuction to get the name of the node which is slected (which you would place when you click the left mouse botton)


i add 5 different nodes (same nodeboxes, different textures) and i have a function that places different nodes (one standing when pointing on ground and one wall-model that gets placed when placing on wall.

(at the moment i use 5 functions, they have the same code except for the code i needed for the 5 different nodes i use), that works but i have unnecessary code

[AMMOnym]

OK, I am lost again :D
Today I tried add some schematics to map, but I failed.
I really dont know, what is wrong on these codes.

Init :

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Code: Select all

local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, ore_per_chunk, height_min, height_max)
   if maxp.y < height_min or minp.y > height_max then
      return
   end
   local y_min = math.max(minp.y, height_min)
   local y_max = math.min(maxp.y, height_max)
   local volume = (maxp.x-minp.x+1)*(y_max-y_min+1)*(maxp.z-minp.z+1)
   local pr = PseudoRandom(seed)
   local num_chunks = math.floor(chunks_per_volume * volume)
   local chunk_size = 3
   if ore_per_chunk <= 4 then
      chunk_size = 2
   end
   local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
   --print("generate_ore num_chunks: "..dump(num_chunks))
   for i=1,num_chunks do
      local y0 = pr:next(y_min, y_max-chunk_size+1)
      if y0 >= height_min and y0 <= height_max then
         local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
         local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
         local p0 = {x=x0, y=y0, z=z0}
         for x1=0,chunk_size-1 do
         for y1=0,chunk_size-1 do
         for z1=0,chunk_size-1 do
            if pr:next(1,inverse_chance) == 1 then
               local x2 = x0+x1
               local y2 = y0+y1
               local z2 = z0+z1
               local p2 = {x=x2, y=y2, z=z2}
               if minetest.env:get_node(p2).name == wherein then
                  minetest.env:set_node(p2, {name=name})
               end
            end
         end
         end
         end
      end
   end
end

minetest.register_on_generated(function(minp, maxp, seed)
generate_ore("pokenodeschems:fake_air", "default:dirt_with_grass", minp, maxp, seed+21,   1/30/30/30,    1, -31000,  100)
end)


Schematics :

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Code: Select all

pokenodesschems = {}

local pokenodesschems_list = {
    { "Pokemon Center", "pkmncenter"},
    { "Pokemon Market", "pkmnmarket"},
    { "Pokemon Stadium", "pkmnstadium"},
}

for i in ipairs(pokenodesschems_list) do
    local builddesc = pokenodesschems_list[i][1]
    local build = pokenodesschems_list[i][2]

minetest.register_node("pokenodesschems:fake_air", {
        description = fake_air,
        tiles = {"fake_air.png"},
      is_ground_content = true,
      groups = {not_in_creative_inventory =1},
        on_place = function(itemstack, placer, pointed_thing)
            if pointed_thing.above then
                local file = io.open(minetest.get_modpath("pokenodesschems").."/schems/"..build..".we")
                local value = file:read("*a")
                file:close()
                local p = pointed_thing.above
                p.x = p.x - 5
                p.z = p.z - 2
                local count = worldedit.deserialize(pointed_thing.above, value)
                itemstack:take_item()
            end
            return itemstack
        end,
    })
end

minetest.register_abm({
    nodenames = {"pokenodesschems:pkmncenter"},
       interval = 1,
   chance = 1,
     action = function(pos)
          if pos then
               local file = io.open(minetest.get_modpath("pokenodesschems").."/schems/pkmncenter.we")
               local value = file:read("*a")
               file:close()
               local p = pos
               p.x = p.x - 5
               p.z = p.z - 2
               local count = worldedit.deserialize(pos, value)
          end
     end,
})

minetest.register_abm({
    nodenames = {"pokenodesschems:pkmnmarket"},
       interval = 5,
   chance = 1,
     action = function(pos)
          if pos then
               local file = io.open(minetest.get_modpath("pokenodesschems").."/schems/pkmnmarket.we")
               local value = file:read("*a")
               file:close()
               local p = pos
               p.x = p.x - 5
               p.z = p.z - 2
               local count = worldedit.deserialize(pos, value)
          end
     end,
})

minetest.register_abm({
    nodenames = {"pokenodesschems:pkmnstadium"},
       interval = 1,
   chance = 1,
     action = function(pos)
          if pos then
               local file = io.open(minetest.get_modpath("pokenodesschems").."/schems/pkmnstadium.we")
               local value = file:read("*a")
               file:close()
               local p = pos
               p.x = p.x - 5
               p.z = p.z - 2
               local count = worldedit.deserialize(pos, value)
          end
     end,
})

If is here any other way(easy one), how to put structures to map by generating, please tell me.

EDIT:

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Code: Select all

15:40:21: ERROR[main]: ServerError: ...op\minetest-0.4.10\bin\..\mods\PKMNS\poke
schems\init.lua:42: attempt to concatenate global 'build' (a nil value)
15:40:21: ERROR[main]: stack traceback:
15:40:21: ERROR[main]:  ...op\minetest-0.4.10\bin\..\mods\PKMNS\pokeschems\init.
lua:42: in function <...op\minetest-0.4.10\bin\..\mods\PKMNS\pokeschems\init.lua
:41>
15:40:21: ERROR[main]:  ...Desktop\minetest-0.4.10\bin\..\builtin\game\register.
lua:348: in function <...Desktop\minetest-0.4.10\bin\..\builtin\game\register.lu
a:336>

This error I get when I use this code :

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Code: Select all

local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, ore_per_chunk, height_min, height_max)
   if maxp.y < height_min or minp.y > height_max then
      return
   end
   local y_min = math.max(minp.y, height_min)
   local y_max = math.min(maxp.y, height_max)
   local volume = (maxp.x-minp.x+1)*(y_max-y_min+1)*(maxp.z-minp.z+1)
   local pr = PseudoRandom(seed)
   local num_chunks = math.floor(chunks_per_volume * volume)
   local chunk_size = 3
   if ore_per_chunk <= 4 then
      chunk_size = 2
   end
   local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
   --print("generate_ore num_chunks: "..dump(num_chunks))
   for i=1,num_chunks do
      local y0 = pr:next(y_min, y_max-chunk_size+1)
      if y0 >= height_min and y0 <= height_max then
         local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
         local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
         local p0 = {x=x0, y=y0, z=z0}
         for x1=0,chunk_size-1 do
         for y1=0,chunk_size-1 do
         for z1=0,chunk_size-1 do
            if pr:next(1,inverse_chance) == 1 then
               local x2 = x0+x1
               local y2 = y0+y1
               local z2 = z0+z1
               local p2 = {x=x2, y=y2, z=z2}
               if minetest.env:get_node(p2).name == wherein then
                  minetest.env:set_node(p2, {name=name})
               end
            end
         end
         end
         end
      end
   end
end

minetest.register_on_generated(function(minp, maxp, seed)
generate_ore("pokeschems:"..build, "default:dirt_with_grass", minp, maxp, seed+21,   1/30/30/30,    1, -31000,  100)
end)


pokeschems = {}

local pokeschems_list = {
    { "Pokemon Center", "pkmncenter"},
    { "Pokemon Market", "pkmnmarket"},
    { "Pokemon Stadium", "pkmnstadium"},   
}

for i in ipairs(pokeschems_list) do
    local builddesc = pokeschems_list[i][1]
    local build = pokeschems_list[i][2]

minetest.register_node("pokeschems:"..build, {
        description = builddesc,
        tiles = {"fake_air.png"},
      is_ground_content = true,
      groups = {not_in_creative_inventory =0},
        on_place = function(itemstack, placer, pointed_thing)
            if pointed_thing.above then
                local file = io.open(minetest.get_modpath("pokeschems").."/schems/"..build..".we")
                local value = file:read("*a")
                file:close()
                local p = pointed_thing.above
                p.x = p.x - 5
                p.z = p.z - 2
                local count = worldedit.deserialize(pointed_thing.above, value)
                itemstack:take_item()
            end
            return itemstack
        end,
    })
end

minetest.register_abm({
    nodenames = {"pokeschems:pkmncenter"},
       interval = 1,
   chance = 1,
     action = function(pos)
          if pos then
               local file = io.open(minetest.get_modpath("pokeschems").."/schems/pkmncenter.we")
               local value = file:read("*a")
               file:close()
               local p = pos
               p.x = p.x - 5
               p.z = p.z - 2
               local count = worldedit.deserialize(pos, value)
          end
     end,
})

minetest.register_abm({
    nodenames = {"pokeschems:pkmnmarket"},
       interval = 1,
   chance = 1,
     action = function(pos)
          if pos then
               local file = io.open(minetest.get_modpath("pokeschems").."/schems/pkmnmarket.we")
               local value = file:read("*a")
               file:close()
               local p = pos
               p.x = p.x - 5
               p.z = p.z - 2
               local count = worldedit.deserialize(pos, value)
          end
     end,
})

minetest.register_abm({
    nodenames = {"pokeschems:pkmnstadium"},
       interval = 1,
   chance = 1,
     action = function(pos)
          if pos then
               local file = io.open(minetest.get_modpath("pokeschems").."/schems/pkmnstadium.we")
               local value = file:read("*a")
               file:close()
               local p = pos
               p.x = p.x - 5
               p.z = p.z - 2
               local count = worldedit.deserialize(pos, value)
          end
     end,
})


[Inocudom]

Hello,
this is my first post in this community, being a linux user I like a lot the idea of an open source and free software game but lets cut to the chase.
Where should one look to create a multiple world mod with scaling, like multiverse for bukkit, to create for example the 9 rings of hell each that scale 1:3 from the precedent world?
Can i call from lua the main mapgen function?
Thank you for your time.
q9c9p

This person made this post in the Freeminer forums. Problem is, those forums are way too quiet. If someone with a solution is willing to post a reply there, it would be greatly appreciated. The place to post it can be found below:
http://forum.freeminer.org/threads/multiple-worlds.181/

[Strikingwolf]

I was wondering how I could require code in another mod and modulize it. For example I know how you would make regular code modular

functions.lua

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Code: Select all

 
local functions = {}

local function myFunction()
    --does stuff
end
functions.myfunction = myfunction

return functions


init.lua

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Code: Select all

local functions = require("functions")
functions.myfunction()


So how could I do this with a core mod or something of the sort?

[kaeza]

Try this:

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Code: Select all

-- module.lua
local m = { }

-- This is local, since it's stored into `m` (which is a local itself).
function m.do_something(foo, bar)
  return foo + bar
end

return m


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Code: Select all

-- init.lua
package.path = package.path .. ";" .. minetest.get_modpath("yourmodname").."/?.lua"

local mymodule = require("module")
local x = mymodule.do_something(1, 2)


[Strikingwolf]

Try this:

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Code: Select all

-- module.lua
local m = { }

-- This is local, since it's stored into `m` (which is a local itself).
function m.do_something(foo, bar)
  return foo + bar
end

return m


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Code: Select all

-- init.lua
package.path = package.path .. ";" .. minetest.get_modpath("yourmodname").."/?.lua"

local mymodule = require("module")
local x = mymodule.do_something(1, 2)


But that doesn't make the core mod kinda thing work right?

[prestidigitator]

I was wondering how I could require code in another mod and modulize it. For example I know how you would make regular code modular
...
So how could I do this with a core mod or something of the sort?

The Minetest developers didn't go the full mile in terms of fully embracing Lua as a platform rather than just a language. You'll find that packages and requires aren't really setup to work right, and there are no mod paths or loaders setup for you or anything. Instead, Minetest uses static mod dependencies to order the loading of mods, and mods are expected to store all non-local functions and variables in global namespace tables based on their own names. The convention looks like:

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Code: Select all

-- This mod is named "parent"
parent = {}
parent.foo = function() ... end


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Code: Select all

-- This mod is named "child" and depends on "parent".
-- There is a line naming "parent" (without quotes) in this mod's depends.txt file.

-- Call parent's function:
parent.foo()


In order to keep code in another Lua file within the same mod (note that in this case you CAN return values like in your example), you can do something more like:

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Code: Select all

local MOD_NAME = minetest.get_current_modname()
local MOD_PATH = minetest.get_modpath(MOD_NAME)

local myModule = dofile(MOD_PATH .. "/myModule.lua")


While you COULD do the same thing with another mod's Lua files, there's no mechanism like 'require' that ensures the code is loaded only once, so you'll get duplicates (with multiple copies of state and/or overwritten globals) if you try it. Not a good idea. I was working on sort of a framework for "mod libraries" when I first started messing with Minetest, but I lost steam and put it on indefinite hold to work on other things. I was probably over-designing version logic in any case.

[MaxPower]

What is the difference between
minetest.get_craft_recipe
and
minetest.get_all_craft_recipes
?

Does minetest.get_craft_recipe give the first recipe only?

/EDIT
I answered my own question and updated the wiki accordingly

[GunshipPenguin]

Hello everybody,

I'm working on a mod that requires a node very similar to bedrock in minecraft called "arenablock". Basically, it will be a node that only people with the "arenabuilder" privilege can place or destroy, otherwise it should be indestructible. So far, this is what I have.

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Code: Select all

minetest.register_node("battles:arenablock", {
   description = "Arenablock",
   tiles = {"arenablock.png"},
   groups = {cracky=1, oddly_breakable_by_hand=1},
   can_dig = function(pos, player)
      local can_access = minetest.check_player_privs(player:get_player_name(), {arenabuilder=true})
      return can_access
   end,
   after_place_node = function(pos, placer, itemstack, pointed_thing)
      local can_access = minetest.check_player_privs(placer:get_player_name(), {arenabuilder=true})
      if can_access == true then
         return
      else
         minetest.set_node(pos, {name="air"})
      end
   end,
})

And it works fine, the problem arises when you use my arenablock node with the TNT mod that is included in minetest_game as the TNT destroys the arenablock when it explodes. Looking at the code for the TNT mod, I see that it uses minetest.remove_node when it explodes to remove the nodes around it and simulate an explosion. My question is this: Is it possible to make arenablock not be destroyed by TNT explosions? I know that I could modify the TNT code so it doesn't destroy the arenablock, but I would prefer modifying my mod's code to make the arenablock immune to TNT explosions.

Thanks in advance for any help :)

[Sokomine]

I know that I could modify the TNT code so it doesn't destroy the arenablock, but I would prefer modifying my mod's code to make the arenablock immune to TNT explosions.

Take a look at how default:cloud is defined. It ought to be sufficient to give your block none of the groups that are relevant for digging. You might also want to ask about that in the TNT mod thread. It ought to remove no blocks that can't be digged. Of course you can't easily dig such blocks, priv nonwithstanding. A special tool might help you there. If you handle the digging about can_dig, players will be able to dig the block and slip through before the server sends the information that it can't be digged.

[4aiman]

GunshipPenguin, THANK YOU VERY MUCH!!! Honestly. You've just gave me an awesome idea! :)

Regards!

[GunshipPenguin]

I know that I could modify the TNT code so it doesn't destroy the arenablock, but I would prefer modifying my mod's code to make the arenablock immune to TNT explosions.

Take a look at how default:cloud is defined. It ought to be sufficient to give your block none of the groups that are relevant for digging. You might also want to ask about that in the TNT mod thread. It ought to remove no blocks that can't be digged. Of course you can't easily dig such blocks, priv nonwithstanding. A special tool might help you there. If you handle the digging about can_dig, players will be able to dig the block and slip through before the server sends the information that it can't be digged.

Hello, Thanks for the reply.

default:cloud is only in one group - not_in_creative_inventory and it still gets destroyed by TNT. Looking at this closely, I'm not sure if it's really possible to make a node that's immune to TNT explosions without editing the TNT code. Because of this, I'm going to try something completely different and ditch the arenablock idea. Thanks for your help and suggestions though!

GunshipPenguin, THANK YOU VERY MUCH!!! Honestly. You've just gave me an awesome idea! :)

Regards!

Awesome!

[MaxPower]

Hello everybody,

And it works fine, the problem arises when you use my arenablock node with the TNT mod that is included in minetest_game as the TNT destroys the arenablock when it explodes. Looking at the code for the TNT mod, I see that it uses minetest.remove_node when it explodes to remove the nodes around it and simulate an explosion. My question is this: Is it possible to make arenablock not be destroyed by TNT explosions? I know that I could modify the TNT code so it doesn't destroy the arenablock, but I would prefer modifying my mod's code to make the arenablock immune to TNT explosions.

This http://dev.minetest.net/minetest.register_node#on_blast may or may not help you

[MaxPower]

Is there a way to list all the registered nodes in LUA ?

[jin_xi]

minetest.registered_nodes is a table of all registered nodes

[MaxPower]

minetest.registered_nodes is a table of all registered nodes

Cheers.

For some reason it is not on the dev wiki, will try this later and eventually add it to it.

[benedict424]

Question: How do I make an ore that spawns in the world?
Reason: I'm working on a mod that makes veriaty in pre-existing ores.

[lag01]

Question: How do I make an ore that spawns in the world?
Reason: I'm working on a mod that makes veriaty in pre-existing ores.

I myself don't know how to do this, but maybe you can check how they do it in moreores mod

[benedict424]

Question: How do I make an ore that spawns in the world?
Reason: I'm working on a mod that makes veriaty in pre-existing ores.

I myself don't know how to do this, but maybe you can check how they do it in moreores mod

I think that it might be simpler to find the code in the game, but I also want to add support to moreores. It might be nessesary.

[philipbenr]

Look at magpen.lua in default. It uses minetest.register_ore function. That one works really well.

[benedict424]

How do I get a node, or and ore, to drop multiple things?

[benedict424]

Look at magpen.lua in default. It uses minetest.register_ore function. That one works really well.

I've just seen that. Thanks.

[Hybrid Dog]

Question: How do I make an ore that spawns in the world?

There's a page about generating ores in minetest.
http://dev.minetest.net/minetest.register_ore

[Hybrid Dog]

How do I get a node, or and ore, to drop multiple things?

https://github.com/minetest/minetest_ga ... s.lua#L328

[RHR]

Is there any way to create light-emitting entities?

[Krock]

Is there any way to create light-emitting entities?

Nope.
*looks with big eyes on this idea* (idea with attached entities to make torches emitting light while holding in the hand)