Modding:WorldGen Concept

This page was last verified for Vintage Story version 1.19.

This article introduces how world generation is handled in Vintage story, and the extent to which it can be modded. It is also intended as a general introduction for modding endeavors in regards to world generation.

Terminology

Important terminology to note while reading this article:

• Chunk: An data structure that holds 32x32x32 blocks. It is of note that chunks do not span the world height.
• Chunk column: A set of chunks spanning the vertical height of the world. Given a world height of 256, a chunk column would represent 8 vertically stacked chunks
• Map chunk: A data structure that holds information on a chunk column, such as the rain height or snow accumulation
• Map Region: A data structure that holds information over an area of 16x16 chunk columns, such as weather and maps required for world generation

Concept

World generation is the process of generating necessary data about the world when the player requires it. World generation is done on a region, map chunk and chunk column basis - each acting as a meaningful subdivision of the world. Each region, map chunk and chunk column is only generated once and stores important data about that area. World generation is very modular. Almost all generated parts of the world, such as ore deposits, creatures or trees, are specified via JSON content mods. On a coding level, each stage of generation triggers an event which the base game registers handlers to. Event handlers can be registered or removed through the API to alter any part of generation.

Content modding

Using content modding, here are the various things that can be added, modified or removed from world generation. Properties relative to world generation are generally located at Vintagestory/assets/survival/worldgen

Moddable content

Item	Description
Deposits	Anything that is "deposited" in the ground on generation, such as ores or patches of blocks like gravel and chalk
Structures	Pre-defined structures, such as the ruins found throughout. The "How to use WorldEdit" page has instructions on building and exporting structures
Trees	Tree and shrub placement
Block layers	Layers of blocks found above the rock layer
Block patches	Patches of blocks, also vegetation
Geological provinces	Geological attributes and placement
Landforms	Land layout and the general arrangement of terrain

Code modding

Using code modding, it is possible to remove any specific part of world generation from the base game entirely, as well as add new functionality.

World types

There are currently three world types - "standard", "superflat", "empty". World types exist under EnumWorldGenPreset. World type has to be specified when registering event handlers for world generation.

Passes

The chunk column generation event is additionally subdivided into passes. Passes are essentially layers in the generation of a chunk column - first laying down the rock layer in one pass, and doing more general cross-chunk actions in later passes, such as flooding them with light or growing patches of grass. Passes exist under EnumWorldGenPass. The pass has to be specified when registering event handlers for chunk column generation.

Index	Name	Description	Requires neighbor chunks
0	None	Nothing generated yet	false
1	Terrain	Basic terrain, rock strata, caves, block layers	false
2	TerrainFeatures	Deposits, structures, ponds	true
3	Vegetation	Block patches, shrubbery and trees, rivulets, sunlight flooding in chunk	true
4	NeighbourSunLightFlood	Snow layer, sunlight flooding to nearby chunks	true
5	PreDone	Done generating, spawn creatures, neighbor chunks might still generate additional things	true
6	Done	Pass is not triggered as an event	-

Events

The generation of either a region (IMapRegion), map chunk (IMapChunk), or chunks contained in that chunk column (IServerChunk and IWorldChunk), triggers an event (in that order). Each of these interfaces holds some specific data about the given region. It is possible to register handlers to events, wherein access is provided for the given interface. The order in which the handlers are assigned is based on the execute order of their specific mod systems.

Accessing events

class Mod : ModSystem
{
    public override double ExecuteOrder()
    {
        // Make sure all delegates have been assigned
        return 10;
    }

    public override void StartServerSide(ICoreServerAPI api)
    {
        // Get the handler for interacting with world generation.
        IWorldGenHandler handler = api.Event.GetRegisteredWorldGenHandlers("standard");

        // Example registering events using a delegate.
        api.Event.ChunkColumnGeneration(/* Handler here */, EnumWorldGenPass.None, "standard");
        api.Event.MapChunkGeneration(/* Handler here */, "standard");
        api.Event.MapRegionGeneration(/* Handler here */, "standard");

        // Retrieving registered handlers.
        List<MapChunkGeneratorDelegate> onMapChunkGen = handler.OnMapChunkGen;
        List<ChunkColumnGenerationDelegate>[] onChunkColGen = handler.OnChunkColumnGen;
        List<MapRegionGeneratorDelegate> onMapRegionGen = handler.OnMapRegionGen;

        foreach (var deleg in onMapChunkGen)
        {
            // Printing class name of delegate instance.
            // This can be useful for finding and removing any particular event from the list.
            api.Server.LogEvent(deleg.Target.ToString());
        }
    } 
}

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