Post your modding questions here

[dpbqRman]

would someone make a big screen nintendo?

[azekill_DIABLO]

when it falls, it's an entity. you should override it. check builtin dir.

Um, how do I override an entity?

override_item("builtin_____") or something like that

[Krock]

Is there a good guide to metadata anywhere?

Item Metadata: https://github.com/minetest/minetest/bl ... .txt#L2968
Use minetest.serialize to convert a table into a string, minetest.deserialize for the reverse.

Node Metadata: lua_api.txt#L2683 and lua_api.txt#L1405

AFAIK, there's no other guide than rubenwardy's and the lua_api.txt file itself. Please specify which metadata type you meant.

Um, how do I override an entity?

You cannot use minetest.override_item for this. Instead, it's possible to access the data table directly:

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Code: Select all

local my_entity_def = minetest.registered_entities["__builtin:<somewhat>"]
my_entity_def.on_step = function(arg1, arg2, foobar)
    -- Things here
end

-- This step is USELESS, 'my_entity_def' is a direct reference to the entity table.
-- These tables are ALWAYS equal, until you call a copy function like 'local foobar = table.copy(blarg)'
minetest.registered_entities["__builtin:<somewhat>"] = my_entity_def


[PlanetKiller]

I'm going to be making a quadruped player and these are a few things I'd like to add.
1. check a specific pixel on the player texture to determine character type (using alpha channel)
2. give character multi-jumps and low grav based upon type
3. swap player model when jumping, or based upon gender
4. modify/view player hitbox

I'm going to use the default player as the base and add these and a few other things. I already have the model and just need to animate it.

[pithy]

Is there a way to make a node kill you when it falls on your head?

Thanks for the answers. I found out how to do this now. Other people can do this the easy way now with my falling_nodes mod.

[kaeza]

1. check a specific pixel on the player texture to determine character type (using alpha channel)

There's no way to read image data in the engine. An alternative is to associate data with each texture (I won't go over how to load and/or define that data) separately of the texture file itself. Except on very rare occasions when you really have no other way, you should not store data in the textures.

2. give character multi-jumps and low grav based upon type

See the `set_physics_override` method of player objects (here's some docs)

3. swap player model when jumping, or based upon gender

Detecting when the player is jumping is not trivial (depending on how accurate you want the results), plus it is subject to lag. Changing per gender should be no problem, though. Take a look at `default.player_set_model` (you should depend on `default` mod).

4. modify/view player hitbox

Not possible at the moment, sorry.

[azekill_DIABLO]

Is it possible to know the texture of a node like this?

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Code: Select all

minetest.register_on_punchnode(function(pos, node, puncher, pointed_thing)
   local node = minetest.get_node_or_nil(pointed_thing.under)
   local tile = node.textures
--...code...
end)

[kaeza]

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Code: Select all

local tiles = minetest.registered_nodes[node.name].tiles
print(tiles[1])


[azekill_DIABLO]

thank you :)

[Icalasari]

Is there a good guide to metadata anywhere?

Item Metadata: https://github.com/minetest/minetest/bl ... .txt#L2968
Use minetest.serialize to convert a table into a string, minetest.deserialize for the reverse.

Node Metadata: lua_api.txt#L2683 and lua_api.txt#L1405

AFAIK, there's no other guide than rubenwardy's and the lua_api.txt file itself. Please specify which metadata type you meant.

Thanks. And yeah it was node metadata - It slipped my mind at the time that item metadata was also a thing

[Krock]

Thanks. And yeah it was node metadata - It slipped my mind at the time that item metadata was also a thing

There's a good example in the Lua API file, it shows how to set (and save) strings and how to create an inventory: https://github.com/minetest/minetest/bl ... .txt#L1405
You can use these functions basically everywhere but only callback functions like on_place really make sense, because it's when a change happens.

I always recommend to look at the source code of other mods when you're not sure how it works ;)

[amadin]

Is

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Code: Select all

[colorize:<color>:<ratio>

decrease a client traffic amount if using "colorize" instead colored textures or not? Server will send to client just text or it will send colored texture created by "colorize"? It not undestand dark_grey and dark_green colors, why?

[kaeza]

Re: traffic, with `[colorize` the server only sends the "base" texture; the client first creates a copy of the texture (possibly loading it from disk first), then modifies it in memory.

Whether or not `[colorize` uses more data depends on many factors which I won't go over here. Just trust me that for all practical purposes it isn't worth even thinking about it. Just use whatever gives the best results visually.

Re: named colors, the list of supported colors is here (here's the source). You probably meant `darkgrey` and `darkgreen` without underscores.

[Icalasari]

There's a good example in the Lua API file, it shows how to set (and save) strings and how to create an inventory: https://github.com/minetest/minetest/bl ... .txt#L1405
You can use these functions basically everywhere but only callback functions like on_place really make sense, because it's when a change happens.

I always recommend to look at the source code of other mods when you're not sure how it works ;)

Thanks again. And yeah, I had checked a few mods that have achieved similar things, but they weren't organized in a way that made sense (Default Wool mod = confusing. Meanwhile a tornado mod I end up 99% understanding off the bat x.x). The other one is getting an item once a day on right click, maybe give it a sub inventory so it can store up to three days worth, but other than figuring out how to get it to reliably check at midnight in game, I'll probably manage to figure that one out now that I have these links, at least to the point that I can get help with a code snippet when I end up crashing the game in new and exotic ways

[taikedz]

If one wanted to make ambient mobs that at most disappeared and put an item or two in the inventory when a specific tool was used on it, would that be something to code from scratch, or use one of the existing mob APIs for?

You can use mobs_redo as it is, then use entity_override to add a special override on mob_punch or on_right_click

viewtopic.php?f=9&t=15518

I'm doing a "bug collecting" mod for my first mod, but other than the tarantula, the others wouldn't need anything complex behaviour wise outside of flight nor a health system, but at the same time I'm not even sure where to begin with making custom AI, and I'm not even sure if Minetest has AI in it as a default

None by default, best bet is mobs_redo for now

If the most complex behaviour a mob may show is flight with a preference of seeking either dark or light along with sky,

To follow the sky/faraway light source would be a tall order... but you could make it fly randomly, checking each node around it for light level, until it found a zone with a light level greater than that of the current node, and cause it to move towards that node...

This would require some significant coding on top of mobs_redo's "mob_step" function, but it would not be insurmountable.... you could use an override, do your light check, if you find better light, move your mob, else if nothing suitable is found, handover to mobs_redo normal code to move randomly...

Will it drop as "fried bug" item if it touches a torch? :D

[D00Med]

I'm saying that in your snippet, you use the `fr1` variable before it gets a value (in the `if` block), thus its value may be nil. More context is needed.

That was my intention - I only want to add fr1 if it doesn't exist already

[PlanetKiller]

1. check a specific pixel on the player texture to determine character type (using alpha channel)

There's no way to read image data in the engine. An alternative is to associate data with each texture (I won't go over how to load and/or define that data) separately of the texture file itself. Except on very rare occasions when you really have no other way, you should not store data in the textures.

Config files come to mind, if I knew how to use them. You've given me some ideas, thanks. I've mainly been using a copy of the player script, but I think overrides will be easier. I'll have to find a way to override the animation lengths since some of my anims had to be a bit longer for four legs.

Thanks.

[Icalasari]

Thanks for all the advice there

Will it drop as "fried bug" item if it touches a torch? :D

And now I need to figure that out somehow. So far the only joke thing in it is that you get a captured stick "bug" by using the recipe of Jar and Stick

[PlanetKiller]

Thanks for all the advice there

Will it drop as "fried bug" item if it touches a torch? :D

And now I need to figure that out somehow. So far the only joke thing in it is that you get a captured stick "bug" by using the recipe of Jar and Stick

I'd check node at position for the torch node and drop item / kill self. I'm guessing you are using on_tick somewhere right?

Currently I'm making another hack tool; to get metadata. I'm trying to get the player via user, then get it's metadata, but I'm unsure how. Nodes are easy, and entities might pose a problem. I'd like to be able to extend node/world/player metadata so I can really start working on my game, but I'm unsure what it looks like or how to access it.

Before saying, use get/set meta, bear in mind I need to get the player/node/entity first. also, nvm, found it.

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Code: Select all

print(user.get_player_name(user))


It vas in mine nodes script zis entire time, ha-ha.

Well, enjoy the tips.

[BirgitLachner]

Okay ... may be an absolut beginner question ...

I tried examples from Rubenwardys Mooding handbook.

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Code: Select all

minetest.register_chatcommand("GiveName", {
   func = function(name, param)
      minetest.show_formspec(name, "turtle_miner:form",
            "size[8,3]" ..
            "label[0,0;Hello, " .. name .. ", what is the name of you turtle?]" ..
            "field[1,1.5;3,1;name;Name;]" ..
            "button_exit[1,2;2,1;exit;Save]")
   end
})

minetest.register_on_player_receive_fields(function(player, formname, fields)
   if formname ~= "turtle_miner:form" then
      return false
   end
   minetest.chat_send_player(player:get_player_name(), "Okay lets call it " .. fields.name .. "!")
   return true
end)


This is okay and even the Output via Chat works. But I want this formspec to be shown when the player clicks with a special item (turtle_miner:remotecontrol) on a special node (turtle_miner:firstturtle).

I tried to do this in steps ... first make a punch on the node to open the fomspec but that causes the Minetest-Game to freeze/crash.

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Code: Select all

minetest.register_node("turtle_miner:firstturtle", {
   description = "First Turtle for Trials",
   tiles = {"turtle_miner_firstturtle_top.png", "turtle_miner_firstturtle_buttom.png", "turtle_miner_firstturtle_right.png", "turtle_miner_firstturtle_left.png", "turtle_miner_firstturtle_back.png", "turtle_miner_firstturtle_front.png"},
   groups={oddly_breakable_by_hand=1},
   on_punch = function(pos, node, puncher, pointed_thing)
      local wielditem = puncher:get_wielded_item()
      local wieldname = wielditem:get_name()
      if wieldname == "turtle_miner:remotecontrol" then
         minetest.show_formspec(puncher, "give_name",
            "size[8,3]" ..
            "label[0,0;Hello, " .. puncher .. "]" ..
            "field[1,1.5;3,1;name;Name;]" ..
            "button_exit[1,2;2,1;exit;Save]")
      else
         minetest.chat_send_player(user:get_player_name(), "Nimm die Fernbedienung!")
      end
   end
})


The error message is, that there is a problem when trying to concatenate "puncher".

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Code: Select all

ERROR[Main]: ServerError: Lua: Runtime error from mod 'turtle_miner' in callback node_on_punch(): /home/birgit/.minetest/mods/turtle_miner/init.lua:19: attempt to concatenate local 'puncher' (a userdata value)
2016-10-12 12:44:50: ERROR[Main]: stack traceback:
2016-10-12 12:44:50: ERROR[Main]:    /home/birgit/.minetest/mods/turtle_miner/init.lua:19: in function </home/birgit/.minetest/mods/turtle_miner/init.lua:11>

Thanks for any help! Birgit

[rubenwardy]

Puncher is a player object, not a name. You need to do

local name = puncher:get_player_name()

[BirgitLachner]

Thanks @Rubenwardy ... *argh* ... really a bit fussy that all. Hopefully I'll remember that with the next problem.

[AB49K]

Hi, I'm creating a mod and I'm new to this, but I'm trying to create a recipe that uses a stack of items.

Is there a way I can use more than 9 items (I'm trying to make an economy mod that converts 100 coins into a higher value coin)

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Code: Select all

minetest.register_craft({
    output = 'cash:platinum',
    type = 'shapeless',
    recipe = {'cash:gold', count = 100, wear = 0, metadata = ''}
})

This runs, but I cannot craft the coins.

Is it possible to use stacks of an item in crafting?

[Hybrid Dog]

>Is it possible to use stacks of an item in crafting?

Using register_craft it's not possible, you can use register_on_craft to do it.
https://github.com/minetest/minetest/bl ... .txt#L2023

[azekill_DIABLO]

Oh thank you! how awesome!

[zm78]

Topic: How do i upload a zip file?
Reason: I want to make a zip file as well as a git file.
More Info: I've tried but it is not working.

[orwell]

Does anyone know why this doesn't work when damage is enabled? The problem seems to be the "if player:hud_get(fr1) == nil", but I don't understand why, or how to get around the problem. It works fine on creative.

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Code: Select all

function tool_anim(player, interval, frame1, frame2, frame3)
   if player:hud_get(fr1) == nil then
   fr1 = player:hud_add({
    hud_elem_type = "image",
    position = {x = 0.5, y = 0.5},
    scale = {
      x = -100,
      y = -100
    },
    text = frame1
   })
   end
...(continues)

fr1 is not initialized, so its nil. hud_get does not like to be called with 'nil', it expects a hud id.
your code should look like this:

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Code: Select all

function tool_anim(player, interval, frame1, frame2, frame3)
   if not fr1 then --if you havent initialized fr1, you can assume the hud does not exist
   fr1 = player:hud_add({
    hud_elem_type = "image",
    position = {x = 0.5, y = 0.5},
    scale = {
      x = -100,
      y = -100
    },
    text = frame1
   })
   end
...(continues)

but remember that this will only work in single player, hud ids are player specific and you store only one at all.
better fr1 is a table.

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Code: Select all

fr1={}
...
if not fr1[player:get_player_name()] then
fr1[player:get_player_name()]=hud_add(...)


[orwell]

Topic: How do i upload a zip file?
Reason: I want to make a zip file as well as a git file.
More Info: I've tried but it is not working.

while posting, scroll down to attachments. just 'add the file' and post

[BirgitLachner]

For the upcomming TurtleMiner ...

Okay ... as you can see in the added picture, I can now punch the turtle with the remote control and there is a fromspec that is shown. I want to create a formspec to move the turtle around with arrow for forward, backward and so on.

turtle1.png (297.62 KiB) Viewed 5169 times

Creating the formspec will not be the big problem. The first will not be really cool but it's just the solve the next thing, to make the node (= the turtle) to move around

I found some ideas how to solve it, within Worldedit, as you can move areas around.

But, I'm not sure, if my idea can work at least ...

1.) Is it possible to have button on the formspec to move the turtle around = to manipulate a node. That means if there can be a direct action from the formspec (I ask, because for the simple shown formspec from the modding handbook the input is analyzed in an other part of the code that the call of the formspec)
2.) I understand that I need to position/id/? of the node to move it but how do I get it? I show the formspec after that call(?) ...

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Code: Select all

function(pos, node, puncher, pointed_thing)

... and want to use something like ...

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Code: Select all

local node = get_node(pos) --obtain current node
local meta = get_meta(pos):to_table() --get metadata of current node
remove_node(pos)
local value = pos[axis] --store current position
pos[axis] = value + amount --move along axis
add_node(pos, node) --move node to new position
get_meta(pos):from_table(meta) --set metadata of new node
pos[axis] = value --restore old position
pos.z = pos.z + 1


(okay ... that's to move an area around ... there need to be changes!!)

Now ... can you give me some hint, what I need to change, where I can find more ides how to realize it?

[Krock]

TL;DR

2.) I understand that I need to position/id/? of the node to move it but how do I get it? I show the formspec after that call(?) ...

1.) Yes
2.) Like this: (whole formspec code & all, untested, needs tweaking)

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Code: Select all

-- Table to know where the players turtles are
local turtle_formspec_positions = {}

minetest.register_node("turtle:turtle", {
   ...
   on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
      -- When the player does a right click on this node

      local player_name = clicker:get_player_name()
      -- Save the last turtle in a table
      turtle_formspec_positions[player_name] = pos

      minetest.show_formspec(player_name, "turtle:control_formspec", "<formspec>")
      return itemstack
   end,
})


-- Catch user inputs from the formspec
minetest.register_on_player_receive_fields(function(sender, formname, fields)
   if formname ~= "turtle:control_formspec" then
      return -- Not a turtle formspec
   end
   local player_name = sender:get_player_name()
   local pos = turtle_formspec_positions[player_name]
   
   if not pos then
      return -- Something went wrong. No position found for this player
   end
   
   local node = minetest.get_node(pos)
   if node.name ~= "turtle:turtle" then
      turtle_formspec_positions[player_name] = nil
      return -- Data invalid. There's no turtle at the given position
   end
   
   local new_pos = vector.new(pos)
   local meta = minetest.get_meta(pos):to_table()
   
   if fields.up then
      -- Button up was pressed
      new_pos.y = new_pos.y + 1
   end
   
   if not vector.equals(pos, new_pos) then
      -- Move node to new position
      
      minetest.remove_node(pos)
      minetest.set_node(new_pos, node) --move node to new position
      minetest.get_meta(new_pos):from_table(meta) --set metadata of new node
      
      -- Update formspec reference position, wait for next instructions
      turtle_formspec_positions[player_name] = pos
   end
end)

License for that is WTFPL/CC0, if you care.