Sheet ore generation

[SegFault22]

I'm trying to get Minetest to generate a bunch of different ores in sheet formations. However, this often results in extremely huge lodes, or miniscule lodes.
So, I want to know what variables can control the frequency of lodes and the size of lodes. My experiments with such have failed horribly.

[Evergreen]

An answer I put together a while ago:

Okay, here is some example code for an ore.

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minetest.register_ore({
    ore_type       = "scatter",
    ore            = "mod:stone_with_ore",
    wherein        = "default:stone",
    clust_scarcity = 8*8*8,
    clust_num_ores = 8,
    clust_size     = 3,
    height_min     = -31000,
    height_max     = 64,
})


To quote the dev wiki:

ore_type: See Ore types
ore: The name of the ore node
wherein: The node that the ore will generate inside of
clust_scarcity: Ore has a 1 out of clust_scarcity chance of spawning in a node.
clust_num_ores: Number of ores in a cluster
clust_size: Size of the bounding box of the cluster
height_min: The lowest level that the ore will generate at
height_max: The highest level that the ore will generate at
noise_threshhold: If noise is above this threshold, ore is placed. Not needed for a uniform distribution
noise_params: NoiseParams structure describing the perlin noise used for ore distribution

Also, the possible ore types are:

scatter

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Randomly chooses a location and generates a cluster of ore.
If noise_params is specified, the ore will be placed if the 3d perlin noise at
that point is greater than the noise_threshhold, giving the ability to create a non-equal
distribution of ore.


sheet

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Creates a sheet of ore in a blob shape according to the 2d perlin noise described by noise_params.
The relative height of the sheet can be controlled by the same perlin noise as well, by specifying
a non-zero 'scale' parameter in noise_params.  IMPORTANT: The noise is not transformed by offset or
scale when comparing against the noise threshhold, but scale is used to determine relative height.
The height of the blob is randomly scattered, with a maximum height of clust_size.
clust_scarcity and clust_num_ores are ignored.
This is essentially an improved version of the so-called "stratus" ore seen in some unofficial mods.


EDIT:

Remember to register the ore as a node first.

Like so:

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Code: Select all

minetest.register_node("yourmod:stone_with_yourore", {
    description = "Your Ore",
    tiles = {"default_stone.png^yourmod_mineral_yourore.png"},
    groups = {cracky=3},
    drop = 'yourmod:yourore_lump',
    sounds = default.node_sound_stone_defaults(),
})


Also remember to change "yourmod" with your mod name, and "youore" with the name of your ore.

Hope that answers your question.

[SegFault22]

An answer I put together a while ago:

Okay, here is some example code for an ore.

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_ore({
    ore_type       = "scatter",
    ore            = "mod:stone_with_ore",
    wherein        = "default:stone",
    clust_scarcity = 8*8*8,
    clust_num_ores = 8,
    clust_size     = 3,
    height_min     = -31000,
    height_max     = 64,
})


To quote the dev wiki:

ore_type: See Ore types
ore: The name of the ore node
wherein: The node that the ore will generate inside of
clust_scarcity: Ore has a 1 out of clust_scarcity chance of spawning in a node.
clust_num_ores: Number of ores in a cluster
clust_size: Size of the bounding box of the cluster
height_min: The lowest level that the ore will generate at
height_max: The highest level that the ore will generate at
noise_threshhold: If noise is above this threshold, ore is placed. Not needed for a uniform distribution
noise_params: NoiseParams structure describing the perlin noise used for ore distribution

Also, the possible ore types are:

scatter

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

Randomly chooses a location and generates a cluster of ore.
If noise_params is specified, the ore will be placed if the 3d perlin noise at
that point is greater than the noise_threshhold, giving the ability to create a non-equal
distribution of ore.


sheet

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

Creates a sheet of ore in a blob shape according to the 2d perlin noise described by noise_params.
The relative height of the sheet can be controlled by the same perlin noise as well, by specifying
a non-zero 'scale' parameter in noise_params.  IMPORTANT: The noise is not transformed by offset or
scale when comparing against the noise threshhold, but scale is used to determine relative height.
The height of the blob is randomly scattered, with a maximum height of clust_size.
clust_scarcity and clust_num_ores are ignored.
This is essentially an improved version of the so-called "stratus" ore seen in some unofficial mods.


EDIT:

Remember to register the ore as a node first.

Like so:

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("yourmod:stone_with_yourore", {
    description = "Your Ore",
    tiles = {"default_stone.png^yourmod_mineral_yourore.png"},
    groups = {cracky=3},
    drop = 'yourmod:yourore_lump',
    sounds = default.node_sound_stone_defaults(),
})


Also remember to change "yourmod" with your mod name, and "youore" with the name of your ore.

Hope that answers your question.

Indeed, it does help greatly. Thank you.
However, I would also like to know which variables to edit so that the frequency of lodes is changed.

[SegFault22]

Scatter distribution on a large scale creates ugly cubes, so that is out. Sheet distribution is the only option.
But to use it properly, we have to be able to change the scarcity of the lodes. Every page I have found fails to explain that, although such is critically important. No wonder nobody uses it except for that technic guy.

[SegFault22]

Scatter distribution on a large scale creates ugly cubes, so that is out. Sheet distribution is the only option.
But to use it properly, we have to be able to change the scarcity of the lodes. Every page I have found fails to explain that, although such is critically important. No wonder nobody uses it except for that technic guy.

there: http://dev.minetest.net/ore
I have problems with the sheet ore, too. For any reason it always generates much and big chunks. Changing the spread didn't help.

Sorry, I have already seen that article. It is not informative enough.
I guess I'll just have to stick to standard ore generation, then...

[paramat]

Despite being confident with noise sheet ores confuse me, it needs more explanation.

[Hybrid Dog]

It is not informative enough.

I know, it's not more informative than lua_api.txt.
EDIT: https://github.com/minetest/minetest/blob/master/src/mapgen.cpp#L182

[SegFault22]

It is not informative enough.

I know, it's not more informative than lua_api.txt.
EDIT: https://github.com/minetest/minetest/blob/master/src/mapgen.cpp#L182

Sorry, I don't speak C++.

[paramat]

I speak a little, i may be able to see how it works ... *looks*

[Hybrid Dog]

I speak a little, i may be able to see how it works ... *looks*

What's the meaning of nthresh?

[paramat]

Noise threshold, so line 202 means 'if noise value < noise threshold'