fxgl-voxel

name	fxgl-voxel
description	Build a voxel or Minecraft-style game in FXGL — store a chunked block grid, generate terrain, place and remove blocks by 3D picking, highlight selected voxels, manage a hotbar of block types, rebuild visible chunk geometry after edits, and save modified chunk data. Use this skill for sandbox voxel worlds, block-building prototypes, or destructible cubic terrain.
triggers	["voxel","minecraft","chunk","block world","place block","break block","chunk mesh","terrain generation"]
compatibility	Java 17+, FXGL 21.x. Requires FXGL 3D mode and builds on fxgl-scene3d.
category	fxgl/3d
tags	["fxgl","java","javafx","3d","game-types","voxel"]
metadata	{"author":"fxgl-skills","version":"1.0","fxgl-version":"21.1"}
allowed-tools	["Read","Write","Edit","Bash"]

FXGL Voxel World

Layering

Use fxgl-scene3d for the basic 3D world and picking behavior. This skill adds:

• chunked world storage
• terrain generation
• place / break interaction
• hotbar block selection
• save/load of modified chunks

Chunk Data

public record ChunkCoord(int x, int z) {}

private static final int CHUNK_SIZE = 16;
private static final int CHUNK_HEIGHT = 64;

private final Map<ChunkCoord, byte[][][]> chunks = new HashMap<>();

Represent air as 0 and solid block IDs as positive values.

Terrain Generation

private byte[][][] generateChunk(ChunkCoord coord) {
    byte[][][] data = new byte[CHUNK_SIZE][CHUNK_HEIGHT][CHUNK_SIZE];

    for (int x = 0; x < CHUNK_SIZE; x++) {
        for (int z = 0; z < CHUNK_SIZE; z++) {
            int worldX = coord.x() * CHUNK_SIZE + x;
               coord.z() * CHUNK_SIZE + z;
               () ( + noise(worldX * , worldZ * ) * );

             (   ; y <= height; y++) {
                data[x][y][z] = () (y == height ?  : );  
            }
        }
    }

     data;
}