Post your modding questions here

[stu]

Why doesn't this work? Or, more specifically, why would this make minetest run at 100% CPU and become unresponsive?

I would guess it has something to do with the 3000+ calls to minetest.set_node. This looks more like a job for the LVM ;-)

Edit: nvm 3000, it's actually more like 12000 :O

[RREDesigns]

Ok, thanks for your time.

I think you are the same guy who wrote the mod manual, so, could you include this information there. Apparently, it is hard to figure out just reading from the API reference, so it would be great help for future readers. I can make some images with marks and tags to explain how pieces in a function fit togheter and how they come to get a value from callbacks. :D

[paramat]

everamzah use the lua voxel manipulator to set those nodes in bulk instead of 12800 individual map accesses.
See my lua mapgen mods for examples (strip out all the noise code).

[Hybrid Dog]

everamzah use the lua voxel manipulator to set those nodes in bulk instead of 12800 individual map accesses.
See my lua mapgen mods for examples (strip out all the noise code).

Somewhere l read that minetest.set_node works faster when it's used in an on_generated, is it true?

[everamzah]

+ Spoiler

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Code: Select all

minetest.register_node("kalite:plastic_grass", {
        tiles = {"default_grass.png"}
})

local c_cloud = minetest.get_content_id("default:cloud")
local c_plastic_grass = minetest.get_content_id("kalite:plastic_grass")
local c_air = minetest.get_content_id("air")

minetest.register_on_generated(function(minp, maxp, seed)
        if maxp.y <= 14360 or
            minp.y >= 14440 then
                return

        local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
        local data = vm:get_data()
        local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}

        local x1 = maxp.x
        local y1 = maxp.y
        local z1 = maxp.z
        local x0 = minp.x
        local y0 = minp.y
        local z0 = minp.z

        for z = z0, z1 do
                for x = x0, x1 do
                        for y = y0, y1 do
                                local vi = area:index(x, y, z)
                                if y == 14400 then
                                        data[vi] = c_cloud
                                elseif y == 14401 then
                                        data[vi] = c_plastic_grass
                                else
                                        data[vi] = c_air
                                end
                        end
                end
        end
        vm:set_data(data)
        --vm:calc_lighting()
        --vm:update_liquids()
        vm:write_to_map()
end)

This is about as far as I've gotten. I started with the example at http://dev.minetest.net/voxel_manipulation#Example -- Am I close?

Edit: This actually works! I'm quite pleased, but am wondering about making it faster. For example, this line: https://github.com/minetest/minetest/bl ... .txt#L2983 talks about using a flat array to make on_generated faster?

[Hybrid Dog]

+ Spoiler

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Code: Select all

minetest.register_node("kalite:plastic_grass", {
        tiles = {"default_grass.png"}
})

local c_cloud = minetest.get_content_id("default:cloud")
local c_plastic_grass = minetest.get_content_id("kalite:plastic_grass")
local c_air = minetest.get_content_id("air")

minetest.register_on_generated(function(minp, maxp, seed)
        if maxp.y <= 14360 or
            minp.y >= 14440 then
                return

        local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
        local data = vm:get_data()
        local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}

        local x1 = maxp.x
        local y1 = maxp.y
        local z1 = maxp.z
        local x0 = minp.x
        local y0 = minp.y
        local z0 = minp.z

        for z = z0, z1 do
                for x = x0, x1 do
                        for y = y0, y1 do
                                local vi = area:index(x, y, z)
                                if y == 14400 then
                                        data[vi] = c_cloud
                                elseif y == 14401 then
                                        data[vi] = c_plastic_grass
                                else
                                        data[vi] = c_air
                                end
                        end
                end
        end
        vm:set_data(data)
        --vm:calc_lighting()
        --vm:update_liquids()
        vm:write_to_map()
end)

This is about as far as I've gotten. I started with the example at http://dev.minetest.net/voxel_manipulation#Example -- Am I close?

Edit: This actually works! I'm quite pleased, but am wondering about making it faster. For example, this line: https://github.com/minetest/minetest/bl ... .txt#L2983 talks about using a flat array to make on_generated faster?

l guess you use singlenode, so you don't need to set air:

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

       for z = z0, z1 do
                for x = x0, x1 do
                        data[area:index(x, 14400, z)] = c_cloud
                        data[area:index(x, 14401, z)] = c_plastic_grass
                end
        end


you could also calculate the area index yourself (l think there are 5*16+2*16-1 z, y, and xs) or use the iter function:

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Code: Select all

       for vi in area:iter(x0, 14400, z0, x1, 14400, z1) do
              data[vi] = c_cloud
       end
       for vi in area:iter(x0, 14401, z0, x1, 14401, z1) do
              data[vi] = c_plastic_grass
       end


And you could change that limit where it generates.

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Code: Select all

if maxp.y < 14400 or
            minp.y > 14401 then
                return

[everamzah]

Oh thank you very much HybridDog! I guess I do have to set air though, because I'm using mgv6. Thanks again.

Edit: This is what I've got now:

+ Spoiler

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Code: Select all

minetest.register_node("kalite:plastic_grass", {
        description = "Plastic Grass",
        tiles = {"default_grass.png"},
        groups = {cracky = default.dig.cobble}
})

local c_cloud = minetest.get_content_id("default:cloud")
local c_plastic_grass = minetest.get_content_id("kalite:plastic_grass")
--local c_air = minetest.get_content_id("air")

minetest.register_on_generated(function(minp, maxp, seed)

        if maxp.y < 14400 or
            minp.y > 14401 then
                return
        end

        local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
        local data = vm:get_data()
        local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}

        local x1 = maxp.x
        local y1 = maxp.y
        local z1 = maxp.z
        local x0 = minp.x
        local y0 = minp.y
        local z0 = minp.z

        for z = z0, z1 do
                for x = x0, x1 do
--3
                        --[[
                        for vi in area:iter(x0, 14400, z0, x1, 14400, z1) do
                                data[vi] = c_cloud
                        end
                        for vi in area:iter(x0, 14401, z0, x1, 14401, z1) do
                                data[vi] = c_plastic_grass
                        end
                        --]]
--2
                        ---[[
                        data[area:index(x, 14400, z)] = c_cloud
                        data[area:index(x, 14401, z)] = c_plastic_grass
                        --]]
--1
                        --[[
                        for y = y0, y1 do
                                local vi = area:index(x, y, z)
                                if y == 14400 then
                                        data[vi] = c_cloud
                                elseif y == 14401 then
                                        data[vi] = c_plastic_grass
                                else
                                        data[vi] = c_air
                                end
                        end
                        --]]
                end
        end

        vm:set_data(data)
        vm:write_to_map()
end)


Option 2 seemed to be the fastest. Also, I tried without air and it still works. Were you talking about the singlenode mapgen or the fact that I was only working with a couple of single nodes?

[stu]

What is the best way to make placement of a certain node require a particular privilege? I am sure this one should be easy but I'm just not seeing it.

[everamzah]

Server Essentials by Gunship Penguin uses some method to restrict placement of TNT nodes, or whatever node you specify in its config. FireGuard by (indriApollo?) uses a priv "fglava" to restrict placing using a lava bucket. Perhaps one of those might do. My first guess was to use after_place_node, however, and check player privs there.

[Don]

I would use on_place and check for priv. If not priv then return else set_node.

[everamzah]

I think using on_place will require managing the itemstack and so on, whereas after_place_node won't.

[Don]

I think using on_place will require managing the itemstack and so on, whereas after_place_node won't.

If you place a node and then use after_place_node wouldn't that mean that you would have to remove the placed node and return it to the player? I might not understand the process of each enough. Could you expand on what you are saying?

[stu]

If you place a node and then use after_place_node wouldn't that mean that you would have to remove the placed node and return it to the player?

Yeah, that's exactly what I am trying to avoid, how does one tell on_place to abort and not actually place anything?

@everamzah, thanks, I will look at those other mods you mentioned.

Edit:To abort on_place you simply return nil, duh :/ Thanks for the replies.

[everamzah]

Not sure about after_place_node without testing, but I wonder if it only visually shows up to the client, and is not actually added. I would be tempted to look at https://github.com/minetest/minetest/bl ... m.lua#L196 -- But that somehow feels improper.

[stu]

Sorry, I edited just as you posted, see above ^

[paramat]

> Somewhere l read that minetest.set_node works faster when it's used in an on_generated, is it true?

I saw that too, i think it is a little faster inside 'on gen' but still much slower than LVM for a large number of nodes.

everamzah, the lua voxelmanips are already flat arrays.
The voxelmanip index always increases by 1 along the x direction, so instead of calculating index per node, calculate the initial index (for x = x0) before the x loop, then increment it by 1 per node.

The end of your code doesn't reset lighting, it should be:

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

   vm:set_data(data)
   vm:set_lighting({day = 0, night = 0})
   vm:calc_lighting()
   vm:write_to_map(data)

[Hybrid Dog]

Oh thank you very much HybridDog! I guess I do have to set air though, because I'm using mgv6. Thanks again.

Edit: This is what I've got now:

+ Spoiler

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_node("kalite:plastic_grass", {
        description = "Plastic Grass",
        tiles = {"default_grass.png"},
        groups = {cracky = default.dig.cobble}
})

local c_cloud = minetest.get_content_id("default:cloud")
local c_plastic_grass = minetest.get_content_id("kalite:plastic_grass")
--local c_air = minetest.get_content_id("air")

minetest.register_on_generated(function(minp, maxp, seed)

        if maxp.y < 14400 or
            minp.y > 14401 then
                return
        end

        local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
        local data = vm:get_data()
        local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}

        local x1 = maxp.x
        local y1 = maxp.y
        local z1 = maxp.z
        local x0 = minp.x
        local y0 = minp.y
        local z0 = minp.z

        for z = z0, z1 do
                for x = x0, x1 do
--3
                        --[[
                        for vi in area:iter(x0, 14400, z0, x1, 14400, z1) do
                                data[vi] = c_cloud
                        end
                        for vi in area:iter(x0, 14401, z0, x1, 14401, z1) do
                                data[vi] = c_plastic_grass
                        end
                        --]]
--2
                        ---[[
                        data[area:index(x, 14400, z)] = c_cloud
                        data[area:index(x, 14401, z)] = c_plastic_grass
                        --]]
--1
                        --[[
                        for y = y0, y1 do
                                local vi = area:index(x, y, z)
                                if y == 14400 then
                                        data[vi] = c_cloud
                                elseif y == 14401 then
                                        data[vi] = c_plastic_grass
                                else
                                        data[vi] = c_air
                                end
                        end
                        --]]
                end
        end

        vm:set_data(data)
        vm:write_to_map()
end)


Option 2 seemed to be the fastest. Also, I tried without air and it still works. Were you talking about the singlenode mapgen or the fact that I was only working with a couple of single nodes?

singlenode mapgen

> Somewhere l read that minetest.set_node works faster when it's used in an on_generated, is it true?

I saw that too, i think it is a little faster inside 'on gen' but still much slower than LVM for a large number of nodes.

How can l determine the least number of nodes LVM works faster if l know the approximate shape?

[everamzah]

everamzah, the lua voxelmanips are already flat arrays.
The voxelmanip index always increases by 1 along the x direction, so instead of calculating index per node, calculate the initial index (for x = x0) before the x loop, then increment it by 1 per node.

The end of your code doesn't reset lighting, it should be:

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

   vm:set_data(data)
   vm:set_lighting({day = 0, night = 0})
   vm:calc_lighting()
   vm:write_to_map(data)

Well I added the bit at the end, but all I noticed change was that the bottom of the cloud is dark. Also, I wonder why write_to_map() worked without passing data to it.

I have to admit I'm pretty lost on what you say about calculating index. I'm using #2:

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

for z = z0, z1 do
  for x = x0, x1 do
    data[area:index(x, 14400, z)] = c_cloud
    data[area:index(x, 14401, z)] = c_plastic_grass
  end
end


Are you referring the the third option with area:iter() ?

[Hybrid Dog]

everamzah, the lua voxelmanips are already flat arrays.
The voxelmanip index always increases by 1 along the x direction, so instead of calculating index per node, calculate the initial index (for x = x0) before the x loop, then increment it by 1 per node.

The end of your code doesn't reset lighting, it should be:

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

   vm:set_data(data)
   vm:set_lighting({day = 0, night = 0})
   vm:calc_lighting()
   vm:write_to_map(data)

Well I added the bit at the end, but all I noticed change was that the bottom of the cloud is dark. Also, I wonder why write_to_map() worked without passing data to it.

I have to admit I'm pretty lost on what you say about calculating index. I'm using #2:

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

for z = z0, z1 do
  for x = x0, x1 do
    data[area:index(x, 14400, z)] = c_cloud
    data[area:index(x, 14401, z)] = c_plastic_grass
  end
end


Are you referring the the third option with area:iter() ?

the indices are numbers
https://github.com/UgnilJoZ/lumpmg/blob/master/init.lua

[everamzah]

I'm aware that the way I'm doing it is very slow. I'm also aware that figuring out how to use indices to make it faster will take me a great deal of time. I put this project on GitHub and the file is https://github.com/everamzah/kalite/blo ... ldedge.lua

[paramat]

I realised you probably want no shadows cast. Disabling lighting calculations is one way, the 'proper' but slower way is to define your grass and cloud nodes to have 'sunlight_propagates = true'.

I'm referring to the second method of your code, the best method.
For the index trick see https://github.com/minetest/minetest_game/blob/master/mods/default/trees.lua#L312
Lines 312-324.
Your second method isn't slow, with the index trick it will be the fastest lua method there is.

[Byakuren]

Is there a way to make entities ignore lighting for their rendering?

[Evergreen]

Is there a way of triggering a function when someone adds an item to an inventory? (or removes, or any action)

[Nathan.S]

Is there a way of triggering a function when someone adds an item to an inventory? (or removes, or any action)

Yep, check this out. http://dev.minetest.net/minetest.regist ... ntory_move

Just call the function in this callback.

[BrunoMine]

I can not serialize an inventory.

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Code: Select all

local player_inv = player:get_inventory()
local list = player_inv:get_list("main")
data_base = minetest.serialize(list)


[rubenwardy]

I can not serialize an inventory.

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Code: Select all

local player_inv = player:get_inventory()
local list = player_inv:get_list("main")
data_base = minetest.serialize(list)


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Code: Select all

local player_inv = player:get_inventory()
local list = player_inv:get_list("main")
local retval = {}
for _, stack in pairs(list) do
    retval[#retval + 1] = stack:to_string()
end
local data_base = minetest.serialize(retval)


then to deserialise

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Code: Select all

local list_strings = minetest.deserialize(text)
local list = {}
for _, str in pairs(list_strings) do
    list[#list + 1] = ItemStack(str)
end


[BrunoMine]

text == data_base ?

[kaeza]

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 player_inv = player:get_inventory()
local list = player_inv:get_list("main")
local retval = {}
for _, stack in pairs(list) do
    retval[#retval + 1] = stack:to_string()
end
local data_base = minetest.serialize(retval)


[...]

It can be edited in-place, and you can use the index from `ipairs` to index instead of using `#t`:

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 player_inv = player:get_inventory()
local list = player_inv:get_list("main")
for i, stack in ipairs(list) do
  list[i] = stack:to_string()
end


Also, I don't recall if `inv:get_list()` may return `nil` items, so you may want to check for that.

[Hybrid Dog]

Your second method isn't slow, with the index trick it will be the fastest lua method there is.

Every chunk at that height has the same look, so you could cache (localize it outside the on_generated) the data table and set the cached one (passing it at that manip:set_data l think) instead of recalculating it, couldn't you?

[rubenwardy]

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 player_inv = player:get_inventory()
local list = player_inv:get_list("main")
local retval = {}
for _, stack in pairs(list) do
    retval[#retval + 1] = stack:to_string()
end
local data_base = minetest.serialize(retval)


[...]

It can be edited in-place, and you can use the index from `ipairs` to index instead of using `#t`:

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 player_inv = player:get_inventory()
local list = player_inv:get_list("main")
for i, stack in ipairs(list) do
  list[i] = stack:to_string()
end


Also, I don't recall if `inv:get_list()` may return `nil` items, so you may want to check for that.

I'm pretty sure it doesn't return nil items, at least it doesn't when you do print(dump(list)). Are you sure that get_list returns a copy?

text == data_base ?

Yes, it's the same string.