Post your mapgen questions here (modding or engine)

[Sokomine]

Yes, I do not want to create decorative items. I want to create structures such as villages.

That was my original intention as well, but it didn't prove to be practical. Most horizontal areas will not be large enough for your village anyway. And it's not exactly cheap to locate such areas. In the end, just changing the terrain in a believable way and pretending it had always looked like that (minus the village of course :-)) works pretty well. The additional advantage is that there's less dependency on the mapgen actually used.

[duane]

Yes, I do not want to create decorative items. I want to create structures such as villages.

That was my original intention as well, but it didn't prove to be practical. Most horizontal areas will not be large enough for your village anyway. And it's not exactly cheap to locate such areas. In the end, just changing the terrain in a believable way and pretending it had always looked like that (minus the village of course :-)) works pretty well. The additional advantage is that there's less dependency on the mapgen actually used.

I did the same with primitive villages, cities, even metal-rich soil for ferns. If you're looking for something, it's always easier to find if you put it there yourself.

[burli]

I think, with the default mapgens it is not possible. They don't provide any informations about the map. Even with heightmap and biome you have still have the problem, that you need to check a lot, e.g. if there are trees in the way.

Structures like buildings should be placed before any other decoration. But this is currently not possible for mods because they run after everything is done. That's why I suggested some kind of Mapgen API a few weeks ago to split map generation in different steps and execute lua mapgens between the steps from the C++ mapgen or replace entire steps

I read a bit about map generation and there are some different types of methodes. Using noises is one of the easiest, but as I mentioned you don't have much information and no control about your map.

I think about something like a "geome" map, geological regions similar to biomes, but with different land shapes like different kind of mountains, mesa, highlands, hills, plateaus, canyons, plains, lakes, of course oceans or even (nearly) flat regions for a village "geome" without any decoration

[paramat]

If you know biome you can avoid trees, or if there are trees you can remove them for a 'vilage in a forest' effect.

[burli]

Of course can I avoid trees, but it is just easier if you have a "village biome"

Removing trees has two problems. It costs time to generate and remove them and removing may result in half cutted tree.

[BrunoMine]

viewtopic.php?f=9&t=15382
This was my attempt to create something. I used the height of the land and avoiding trees (simply canceling the placement of the village). The code is not very clean, but the results are very interesting.

[burli]

Removing trees has two problems. It costs time to generate and remove them and removing may result in half cutted tree.

Needed 30 seconds to find an example in BrunoMine's mod. That can always happen if you place trees first

[BrunoMine]

This should be a check failure, it should not happen.

[burli]

This should be a check failure, it should not happen.

I flew around for a few minutes and I found lots of examples. Here is a tree decaying

[BrunoMine]

I performed the necessary corrections. The houses are not built in place of trees.
I checked for 1 minute and found the error.
Download again DEV version of the project.

[burli]

Even if it works it takes additional time while map generation and you can't build a house or village in a forest

It's like building a house from the roof down to the cellar. It may work, but it takes more time and the result might be different from what you want

If I would write a mapgen I would place the buildings first, then the trees

[duane]

Even if it works it takes additional time while map generation and you can't build a house or village in a forest

It's like building a house from the roof down to the cellar. It may work, but it takes more time and the result might be different from what you want

If I would write a mapgen I would place the buildings first, then the trees

Write that mapgen!

Seriously, there's nothing stopping you from placing everything yourself. Gael de Sailly did it, and valleys mapgen was very popular when I discovered minetest. (Sadly, I think I scuttled it when I converted it to C, even though you can still place all the valleys decorations on top of the C mapgen.)

Yes, it's going to take more CPU time, but if you're doing any modifications via voxelmanip, you've already spent most of that time. Anyway, liquid and light handling are the worst time wasters for me, no matter where the bits and pieces are being placed. Gael de Sailly had it right. Do everything yourself as long as you're doing any of it and save the time the regular mapgen would take.

If I were really clever, I'd write the basics (or steal them from valleys) with single node setting and overload the voxelmanip functions so that all other mods worked through my framework, so that data was only read and written once, and lighting and liquid calculations happened once at the end of the process. Cut the C mapgens out altogether!

But I'm blithering again...

[burli]

Write that mapgen!

Seriously, there's nothing stopping you from placing everything yourself. Gael de Sailly did it, and valleys mapgen was very popular when I discovered minetest. (Sadly, I think I scuttled it when I converted it to C, even though you can still place all the valleys decorations on top of the C mapgen.)

Yes, it's going to take more CPU time, but if you're doing any modifications via voxelmanip, you've already spent most of that time. Anyway, liquid and light handling are the worst time wasters for me, no matter where the bits and pieces are being placed. Gael de Sailly had it right. Do everything yourself as long as you're doing any of it and save the time the regular mapgen would take.

If I were really clever, I'd write the basics (or steal them from valleys) with single node setting and overload the voxelmanip functions so that all other mods worked through my framework, so that data was only read and written once, and lighting and liquid calculations happened once at the end of the process. Cut the C mapgens out altogether!

But I'm blithering again...

We both know that there is an ugly 1GB limit, if you would like to do this in Lua. I don't think that it is possible to write the mapgen I have in mind in Lua and I don't have the C++ skills to write a native mapgen.

Nevertheless I will write my own mapgen, but more to get programming skills than to make an actual mapgen

[burli]

How do I create a voronoi diagram and how do I use it?

[qwertymine3]

How do I create a voronoi diagram and how do I use it?

You can either generate it pixel by pixel, by testing the distance to each point near the pixel and finding the closest.
Here is a good explanation of how to do this: http://web.archive.org/web/20160419063123/https://aftbit.com/cell-noise-2/

Or you can generate a diagram of vectors which bound the 'cells', using an algorithm such as fortunes algorithm. To use this, you would then have to use an algorithm to render the polygons.

For minetest mapgen, the former method is fast enough for 2d noise. 3d noise is very hard to optimise with the former method, and would requires some advanced algorithms with the latter method.

[burli]

Ok, let's make an example with biomes in Minetest. Each biome is represented by a 2d coordinate

How do I define the coordinates to get well balanced biomes? Try and error? Is there a (Linux) tool that visualise the diagram?

If I register a tree Minetest just gets the coordinate of the biome. If the mapgen wants to place a tree he sends the tree coordinate to the (built-in) voronoi algorithm and gets the biome as result back.

Is that correct so far?

[qwertymine3]

Ok, let's make an example with biomes in Minetest. Each biome is represented by a 2d coordinate

How do I define the coordinates to get well balanced biomes? Try and error? Is there a (Linux) tool that visualise the diagram?

I'm not an expert on balancing biomes in this way, but Gael de Sailly used GeoGebra (web app and native app for linux), to create a voronoi diagram for his experimental 30 biomes mod.

[burli]

Ok, let's make an example with biomes in Minetest. Each biome is represented by a 2d coordinate

How do I define the coordinates to get well balanced biomes? Try and error? Is there a (Linux) tool that visualise the diagram?

I'm not an expert on balancing biomes in this way, but Gael de Sailly used GeoGebra (web app and native app for linux), to create a voronoi diagram for his experimental 30 biomes mod.

I found GeoGebra, but I have no idea how to create Voronoi diargams in this program. I hope he reads here and can make a little tutorial. Because everything I found yet was not in english. I installed GeoGebra and I see that I can move these points, but I have no idea how to start from scratch

Edit: got it, but not as he does. Some help would still be nice

[burli]

v5 is currently my favorite mapgen. I tinker around with noise parameters and found a setting with much less floating islands and still fancy mountains. I prefere settings with higher lacunarity and lower persistence and I disabled eased, cause this causes these fancy blobs that I don't like



here is the full map_meta.txt for reference. But I just changed mgv5_np_ground

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Code: Select all

chunksize = 5
mg_biome_np_heat = {
   flags = defaults
   lacunarity = 2
   octaves = 3
   offset = 50
   persistence = 0.5
   scale = 50
   seed = 5349
   spread = (750,750,750)
}
mg_biome_np_heat_blend = {
   flags = defaults
   lacunarity = 2
   octaves = 2
   offset = 0
   persistence = 1
   scale = 1.5
   seed = 13
   spread = (8,8,8)
}
mg_biome_np_humidity = {
   flags = defaults
   lacunarity = 2
   octaves = 3
   offset = 50
   persistence = 0.5
   scale = 50
   seed = 842
   spread = (750,750,750)
}
mg_biome_np_humidity_blend = {
   flags = defaults
   lacunarity = 2
   octaves = 2
   offset = 0
   persistence = 1
   scale = 1.5
   seed = 90003
   spread = (8,8,8)
}
mg_flags = nocaves, nodungeons, light, decorations
mg_name = v5
mgv5_cave_width = 0.125
mgv5_np_cave1 = {
   flags = defaults
   lacunarity = 2
   octaves = 4
   offset = 0
   persistence = 0.5
   scale = 12
   seed = 52534
   spread = (50,50,50)
}
mgv5_np_cave2 = {
   flags = defaults
   lacunarity = 2
   octaves = 4
   offset = 0
   persistence = 0.5
   scale = 12
   seed = 10325
   spread = (50,50,50)
}
mgv5_np_factor = {
   flags = defaults
   lacunarity = 2
   octaves = 3
   offset = 0
   persistence = 0.45
   scale = 1
   seed = 920381
   spread = (250,250,250)
}
mgv5_np_filler_depth = {
   flags = defaults
   lacunarity = 2
   octaves = 4
   offset = 0
   persistence = 0.7
   scale = 1
   seed = 261
   spread = (150,150,150)
}
mgv5_np_ground = {
   flags = defaults
   lacunarity = 3
   octaves = 4
   offset = 15
   persistence = 0.25
   scale = 40
   seed = 983240
   spread = (80,80,80)
}
mgv5_np_height = {
   flags = defaults
   lacunarity = 2
   octaves = 4
   offset = 0
   persistence = 0.5
   scale = 10
   seed = 84174
   spread = (250,250,250)
}
mgv5_spflags =
seed = 10451164194390179830
water_level = 1
[end_of_params]


[azekill_DIABLO]

nice! but i got some but with too big values.

[burli]

It is impossible to remove all floating islands in v5. All you can do is reduce lacunarity and persistence to really low values, but then you have boring hills

Edit: and even that doesn't help. That's the nature of the v5 mg

[Sokomine]

Of course can I avoid trees, but it is just easier if you have a "village biome"

In a way that's what nores mg mapgen did: Add some noise and superimpose a village biome, or rather: a function that provides distinction between is-inside-village/is-not-inside-village. My mg_villages mod uses this mechanism provided by nore.

Needed 30 seconds to find an example in BrunoMine's mod. That can always happen if you place trees first

Such things can always happen. I go to considerable effort to remove anything tree-like inside my villages before the first house is placed. Paramat created the code for the terrain blending at the borders of each village. Any trees found there are located, removed, their positions remembered, and afterwards new saplings/trees are placed at the new hight. But even with that much effort in place, there will still be errors and oddities now and then.

Yes, it's going to take more CPU time, but if you're doing any modifications via voxelmanip, you've already spent most of that time.

That's right. Unless you screw up badly in your code. reading the voxelarea data and writing it back takes a significant amount of time compared to all the rest that's done inside the area.

If I were really clever, I'd write the basics (or steal them from valleys) with single node setting and overload the voxelmanip functions so that all other mods worked through my framework, so that data was only read and written once, and lighting and liquid calculations happened once at the end of the process. Cut the C mapgens out altogether!

All other mods working through the framework, so that the voxelmanip area data needs to be read and written only once? That is very tempting. It might speed some things up considerably. Having a chain of mods that get mapgen data passed on, which then do their work on it, and liquid and lighting update done just at the very end...that could be very helpful.

I is impossible to remove all floating islands in v5. All you can do is reduce lacunarity and persistence to really low values, but then you have boring hills

Edit: and even that doesn't help. That's the nature of the v5 mg

That's why I like other mapgens more. More realistic terrain, less floating mountains, better terrain to build on. My villages also aren't particulary happy if mountains get too high as I don't apply the generator to all mapchunks in height; mapchunks which will not get a village (too deep or too high) aren't touched at all in order to speed things up.

[burli]

If I were really clever, I'd write the basics (or steal them from valleys) with single node setting and overload the voxelmanip functions so that all other mods worked through my framework, so that data was only read and written once, and lighting and liquid calculations happened once at the end of the process. Cut the C mapgens out altogether!

All other mods working through the framework, so that the voxelmanip area data needs to be read and written only once? That is very tempting. It might speed some things up considerably. Having a chain of mods that get mapgen data passed on, which then do their work on it, and liquid and lighting update done just at the very end...that could be very helpful.

I had a similar idea. I opend an issue on github for a "mapgen API". Currently all mapgens are hard coded. My idea was, that all functions of a mapgen (terrain, biomes, caves, decoration...) are registered in a table and it should be possible to add or remove any part of the mapgen. The mapgen runs through the table and calls each function, no matter if C++ or Lua. But this would mean that each lua mod has to load the VoxelManip. This could only be eliminated if the mapgen is completely written in lua.

That's why I like other mapgens more. More realistic terrain, less floating mountains, better terrain to build on.

With my changes v5 isn't that bad. There are still floating islands, but much less than before. And there are also relative flat areas.

But to be honest there is no mapgen that really fits my expectations. I will use my modified v5 mapgen for my next experiments with biomes. Apart from the floating islands v5 has some nice landscapes

[paramat]

> How do I define the coordinates to get well balanced biomes? Try and error? Is there a (Linux) tool that visualise the diagram?

It's tough work i'm doing right now, i'm intending to use GeoGebra but currently i draw the points on graph paper and draw the equidistant lines by hand. For every pair of points draw the line that is halfway between, these lines define the edges of the voronoi 'cells'.
More info here https://forum.minetest.net/viewtopic.php?f=47&t=11603

[paramat]

Not in English but helpful https://www.youtube.com/watch?v=FcjpNeF4dVQ&feature=youtu.be&t=131
I'll post some extra tips soon.
My result https://github.com/minetest/minetest_game/pull/1022#issuecomment-241926438

[paramat]

GeoGebra

Click 'move graphics view' button, click and drag axes and mouse wheel to zoom out until -20 to 120 is shown on both axes.
Options > point capturing [off].
Options > rounding [0 decimal places]. All point co-ordinates will snap to nearest integer.
Click 'new point' button.
Click on the graphics view to place a point, then click and drag point while watching co-ordinates.
Repeat for all biome points.
In the 'input' command line type "{A,B,C, ..}" then [enter] to combine points into a group, "list1" should appear on the left.
Type "Voronoi[list1]" [enter].
Cick and move points as desired.
To print the graphics view: File > export > graphics view as picture (png).
Unselect 'transparent' box, reset 'scale' as desired then [save].

[burli]

Thanks. Meanwhile I was able to make a diagram, but I had some extra steps to create a list.

[burli]

Maybe someone find this useful. This is the most simple Lua mapgen. Just generates stone and water

And maybe someone can replace the example in the get_perlin_map Wiki page. It does not work. I need a while until I found that get2dMap_flat doesn't want 3d coordinates

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Code: Select all

minetest.set_mapgen_params({mgname="singlenode"})

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

   local c_stone = minetest.get_content_id("default:stone")
   local c_water = minetest.get_content_id("default:water_source")
   local c_air = minetest.get_content_id("air")
   local c_ignore = minetest.get_content_id("ignore")

   local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
   local data = vm:get_data()
   local a = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
   local csize = vector.add(vector.subtract(maxp, minp), 1)

   local write = false

   local noise_1 = minetest.get_perlin_map({offset = 5,
                                      scale = 15,
                                      seed = 1234,
                                      spread = {x = 250, y = 250, z = 250},
                                      octaves = 5,
                                      persist = 0.6,
                                      lacunarity = 2,
                                      flags = "defaults"},
                                      csize):get2dMap_flat({x=minp.x, y=minp.z})   
   local index2d = 0
   for z = minp.z, maxp.z do
   for y = minp.y, maxp.y do
   for x = minp.x, maxp.x do
         
      index2d = (z - minp.z) * csize.x + (x - minp.x) + 1   
      local ivm = a:index(x, y, z)

      if y < noise_1[index2d] then
         data[ivm] = c_stone
         write = true
      elseif y > noise_1[index2d] and y < 1 then
         data[ivm] = c_water
         write = true
      end
   end
   end
   end

   if write then
      vm:set_data(data)
      vm:set_lighting({day = 0, night = 0})
      vm:calc_lighting()
      vm:update_liquids()
      vm:write_to_map()
   end

end

[paramat]

You can speed that up by setting 'mg_flags = nolight' and removing 'vm:set_lighting({day = 0, night = 0})'
But you will need to 'write' in all mapchunks.
Also, the 'csize' used in 'get perlinmap' should have it's z component set to 1, otherwise you can end up using 80 times more data.
Perhaps i need to write another super-simple example mapgen.

[paramat]

This is an IRC chat with hmmmm that is useful information about 'noise flags':

///////////////////

<hmmmm> leave flags blank for noise just like you're used to, eased/non-eased is determined by the type of noise it's being used for
<hmmmm> 2d noise uses eased by default
<hmmmm> 3d noise uses non-eased by default
<hmmmm> this is needed for backwards compatibility
<hmmmm> if you want to do something a little different though... you need to specify the flags field
<hmmmm> 2d noise with the "eased" flag does nothing really because it's already eased by default
<paramat> 2d noise has always been eased then?
<hmmmm> yup
<hmmmm> if you specify "noeased" though, or just have the flags field present without "eased" present, it'll disable easing on 2d noise
<hmmmm> if you specify "eased" on 3d noise, it'll ease your 3d noise
<hmmmm> if you specify "noeased" on 3d noise or leave nothing at all, it'll be regular 3d noise
<hmmmm> let's say you want absolute noise but you don't want to specify eased or not eased
<hmmmm> you'd specify defaults instead
<hmmmm> flags = "defaults, absvalue" would make the noise eased or not eased based on if it's being used for 2d or 3d noise

///////////////////

'easing' is a 'smoothing' of noise, the lack of eased 3D noise in mgv7 is what creates the gridlike effect and spikyness, especially noticeable on a map overview.
Mgv5 3D noise is 'eased' so is smooth and blobby.

'absvalue' uses the absolute value of each octave of noise before combining them.
Combined with eased noise it tends to create convex forms, it looks 'bubbly' like a cumulus cloud.
Combined with uneased noise creates mountainlike forms almost like intersecting pyramids.