Written for GDScript
Based on my own Marching Cubes table generation algorithm from ~2018.
Labelling (used whilst working out the algorithm again -- hasn't been cleaned up)
The output format is as follows:
{ edgeCount, e1, e2, ..., eN, edgeCount, e1, ..., eN, -1 };
Where edgeCount refers to how many edge indices follow in the array.
An array row may feature 0 or more { edgeCount, e1, e2, ..., eN }, for as many times as needed.
-1 marks the end of the array (terminator).
Generates the following table:
const s_edgeLookup = [
[ -1, ],
[ 3, 0, 4, 3, -1, ],
[ 3, 0, 1, 5, -1, ],
[ 4, 1, 5, 4, 3, -1, ],
[ 3, 1, 2, 6, -1, ],
[ 3, 0, 4, 3, 3, 1, 2, 6, -1, ],
[ 4, 0, 2, 6, 5, -1, ],
[ 5, 2, 6, 5, 4, 3, -1, ],
[ 3, 2, 3, 7, -1, ],
[ 4, 0, 4, 7, 2, -1, ],
[ 3, 0, 1, 5, 3, 2, 3, 7, -1, ],
[ 5, 1, 5, 4, 7, 2, -1, ],
[ 4, 1, 3, 7, 6, -1, ],
[ 5, 0, 4, 7, 6, 1, -1, ],
[ 5, 0, 3, 7, 6, 5, -1, ],
[ 4, 7, 6, 5, 4, -1, ],
[ 3, 9, 8, 5, -1, ],
[ 3, 0, 4, 3, 3, 9, 8, 5, -1, ],
[ 4, 0, 1, 9, 8, -1, ],
[ 5, 1, 9, 8, 4, 3, -1, ],
[ 3, 1, 2, 6, 3, 9, 8, 5, -1, ],
[ 3, 0, 4, 3, 3, 1, 2, 6, 3, 9, 8, 5, -1, ],
[ 5, 0, 2, 6, 9, 8, -1, ],
[ 6, 2, 6, 9, 8, 4, 3, -1, ],
[ 3, 2, 3, 7, 3, 9, 8, 5, -1, ],
[ 4, 0, 4, 7, 2, 3, 9, 8, 5, -1, ],
[ 4, 0, 1, 9, 8, 3, 2, 3, 7, -1, ],
[ 6, 1, 9, 8, 4, 7, 2, -1, ],
[ 4, 1, 3, 7, 6, 3, 9, 8, 5, -1, ],
[ 5, 0, 4, 7, 6, 1, 3, 9, 8, 5, -1, ],
[ 6, 0, 3, 7, 6, 9, 8, -1, ],
[ 5, 7, 6, 9, 8, 4, -1, ],
[ 3, 8, 11, 4, -1, ],
[ 4, 0, 8, 11, 3, -1, ],
[ 3, 0, 1, 5, 3, 8, 11, 4, -1, ],
[ 5, 1, 5, 8, 11, 3, -1, ],
[ 3, 1, 2, 6, 3, 8, 11, 4, -1, ],
[ 4, 0, 8, 11, 3, 3, 1, 2, 6, -1, ],
[ 4, 0, 2, 6, 5, 3, 8, 11, 4, -1, ],
[ 6, 2, 6, 5, 8, 11, 3, -1, ],
[ 3, 2, 3, 7, 3, 8, 11, 4, -1, ],
[ 5, 0, 8, 11, 7, 2, -1, ],
[ 3, 0, 1, 5, 3, 2, 3, 7, 3, 8, 11, 4, -1, ],
[ 6, 1, 5, 8, 11, 7, 2, -1, ],
[ 4, 1, 3, 7, 6, 3, 8, 11, 4, -1, ],
[ 6, 0, 8, 11, 7, 6, 1, -1, ],
[ 5, 0, 3, 7, 6, 5, 3, 8, 11, 4, -1, ],
[ 5, 8, 11, 7, 6, 5, -1, ],
[ 4, 5, 9, 11, 4, -1, ],
[ 5, 0, 5, 9, 11, 3, -1, ],
[ 5, 0, 1, 9, 11, 4, -1, ],
[ 4, 1, 9, 11, 3, -1, ],
[ 3, 1, 2, 6, 4, 5, 9, 11, 4, -1, ],
[ 5, 0, 5, 9, 11, 3, 3, 1, 2, 6, -1, ],
[ 6, 0, 2, 6, 9, 11, 4, -1, ],
[ 5, 2, 6, 9, 11, 3, -1, ],
[ 3, 2, 3, 7, 4, 5, 9, 11, 4, -1, ],
[ 6, 0, 5, 9, 11, 7, 2, -1, ],
[ 5, 0, 1, 9, 11, 4, 3, 2, 3, 7, -1, ],
[ 5, 1, 9, 11, 7, 2, -1, ],
[ 4, 1, 3, 7, 6, 4, 5, 9, 11, 4, -1, ],
[ 7, 0, 5, 9, 11, 7, 6, 1, -1, ],
[ 7, 0, 3, 7, 6, 9, 11, 4, -1, ],
[ 4, 9, 11, 7, 6, -1, ],
[ 3, 11, 10, 7, -1, ],
[ 3, 0, 4, 3, 3, 11, 10, 7, -1, ],
[ 3, 0, 1, 5, 3, 11, 10, 7, -1, ],
[ 4, 1, 5, 4, 3, 3, 11, 10, 7, -1, ],
[ 3, 1, 2, 6, 3, 11, 10, 7, -1, ],
[ 3, 0, 4, 3, 3, 1, 2, 6, 3, 11, 10, 7, -1, ],
[ 4, 0, 2, 6, 5, 3, 11, 10, 7, -1, ],
[ 5, 2, 6, 5, 4, 3, 3, 11, 10, 7, -1, ],
[ 4, 2, 3, 11, 10, -1, ],
[ 5, 0, 4, 11, 10, 2, -1, ],
[ 3, 0, 1, 5, 4, 2, 3, 11, 10, -1, ],
[ 6, 1, 5, 4, 11, 10, 2, -1, ],
[ 5, 1, 3, 11, 10, 6, -1, ],
[ 6, 0, 4, 11, 10, 6, 1, -1, ],
[ 6, 0, 3, 11, 10, 6, 5, -1, ],
[ 5, 11, 10, 6, 5, 4, -1, ],
[ 3, 9, 8, 5, 3, 11, 10, 7, -1, ],
[ 3, 0, 4, 3, 3, 9, 8, 5, 3, 11, 10, 7, -1, ],
[ 4, 0, 1, 9, 8, 3, 11, 10, 7, -1, ],
[ 5, 1, 9, 8, 4, 3, 3, 11, 10, 7, -1, ],
[ 3, 1, 2, 6, 3, 9, 8, 5, 3, 11, 10, 7, -1, ],
[ 3, 0, 4, 3, 3, 1, 2, 6, 3, 9, 8, 5, 3, 11, 10, 7, -1, ],
[ 5, 0, 2, 6, 9, 8, 3, 11, 10, 7, -1, ],
[ 6, 2, 6, 9, 8, 4, 3, 3, 11, 10, 7, -1, ],
[ 4, 2, 3, 11, 10, 3, 9, 8, 5, -1, ],
[ 5, 0, 4, 11, 10, 2, 3, 9, 8, 5, -1, ],
[ 4, 0, 1, 9, 8, 4, 2, 3, 11, 10, -1, ],
[ 7, 1, 9, 8, 4, 11, 10, 2, -1, ],
[ 5, 1, 3, 11, 10, 6, 3, 9, 8, 5, -1, ],
[ 6, 0, 4, 11, 10, 6, 1, 3, 9, 8, 5, -1, ],
[ 7, 0, 3, 11, 10, 6, 9, 8, -1, ],
[ 6, 11, 10, 6, 9, 8, 4, -1, ],
[ 4, 8, 10, 7, 4, -1, ],
[ 5, 0, 8, 10, 7, 3, -1, ],
[ 3, 0, 1, 5, 4, 8, 10, 7, 4, -1, ],
[ 6, 1, 5, 8, 10, 7, 3, -1, ],
[ 3, 1, 2, 6, 4, 8, 10, 7, 4, -1, ],
[ 5, 0, 8, 10, 7, 3, 3, 1, 2, 6, -1, ],
[ 4, 0, 2, 6, 5, 4, 8, 10, 7, 4, -1, ],
[ 7, 2, 6, 5, 8, 10, 7, 3, -1, ],
[ 5, 2, 3, 4, 8, 10, -1, ],
[ 4, 0, 8, 10, 2, -1, ],
[ 3, 0, 1, 5, 5, 2, 3, 4, 8, 10, -1, ],
[ 5, 1, 5, 8, 10, 2, -1, ],
[ 6, 1, 3, 4, 8, 10, 6, -1, ],
[ 5, 0, 8, 10, 6, 1, -1, ],
[ 7, 0, 3, 4, 8, 10, 6, 5, -1, ],
[ 4, 8, 10, 6, 5, -1, ],
[ 5, 5, 9, 10, 7, 4, -1, ],
[ 6, 0, 5, 9, 10, 7, 3, -1, ],
[ 6, 0, 1, 9, 10, 7, 4, -1, ],
[ 5, 1, 9, 10, 7, 3, -1, ],
[ 3, 1, 2, 6, 5, 5, 9, 10, 7, 4, -1, ],
[ 6, 0, 5, 9, 10, 7, 3, 3, 1, 2, 6, -1, ],
[ 7, 0, 2, 6, 9, 10, 7, 4, -1, ],
[ 6, 2, 6, 9, 10, 7, 3, -1, ],
[ 6, 2, 3, 4, 5, 9, 10, -1, ],
[ 5, 0, 5, 9, 10, 2, -1, ],
[ 7, 0, 1, 9, 10, 2, 3, 4, -1, ],
[ 4, 1, 9, 10, 2, -1, ],
[ 7, 1, 3, 4, 5, 9, 10, 6, -1, ],
[ 6, 0, 5, 9, 10, 6, 1, -1, ],
[ 3, 0, 3, 4, 3, 9, 10, 6, -1, ],
[ 3, 9, 10, 6, -1, ],
[ 3, 10, 9, 6, -1, ],
[ 3, 0, 4, 3, 3, 10, 9, 6, -1, ],
[ 3, 0, 1, 5, 3, 10, 9, 6, -1, ],
[ 4, 1, 5, 4, 3, 3, 10, 9, 6, -1, ],
[ 4, 1, 2, 10, 9, -1, ],
[ 3, 0, 4, 3, 4, 1, 2, 10, 9, -1, ],
[ 5, 0, 2, 10, 9, 5, -1, ],
[ 6, 2, 10, 9, 5, 4, 3, -1, ],
[ 3, 2, 3, 7, 3, 10, 9, 6, -1, ],
[ 4, 0, 4, 7, 2, 3, 10, 9, 6, -1, ],
[ 3, 0, 1, 5, 3, 2, 3, 7, 3, 10, 9, 6, -1, ],
[ 5, 1, 5, 4, 7, 2, 3, 10, 9, 6, -1, ],
[ 5, 1, 3, 7, 10, 9, -1, ],
[ 6, 0, 4, 7, 10, 9, 1, -1, ],
[ 6, 0, 3, 7, 10, 9, 5, -1, ],
[ 5, 7, 10, 9, 5, 4, -1, ],
[ 4, 6, 10, 8, 5, -1, ],
[ 3, 0, 4, 3, 4, 6, 10, 8, 5, -1, ],
[ 5, 0, 1, 6, 10, 8, -1, ],
[ 6, 1, 6, 10, 8, 4, 3, -1, ],
[ 5, 1, 2, 10, 8, 5, -1, ],
[ 3, 0, 4, 3, 5, 1, 2, 10, 8, 5, -1, ],
[ 4, 0, 2, 10, 8, -1, ],
[ 5, 2, 10, 8, 4, 3, -1, ],
[ 3, 2, 3, 7, 4, 6, 10, 8, 5, -1, ],
[ 4, 0, 4, 7, 2, 4, 6, 10, 8, 5, -1, ],
[ 5, 0, 1, 6, 10, 8, 3, 2, 3, 7, -1, ],
[ 7, 1, 6, 10, 8, 4, 7, 2, -1, ],
[ 6, 1, 3, 7, 10, 8, 5, -1, ],
[ 7, 0, 4, 7, 10, 8, 5, 1, -1, ],
[ 5, 0, 3, 7, 10, 8, -1, ],
[ 4, 7, 10, 8, 4, -1, ],
[ 3, 8, 11, 4, 3, 10, 9, 6, -1, ],
[ 4, 0, 8, 11, 3, 3, 10, 9, 6, -1, ],
[ 3, 0, 1, 5, 3, 8, 11, 4, 3, 10, 9, 6, -1, ],
[ 5, 1, 5, 8, 11, 3, 3, 10, 9, 6, -1, ],
[ 4, 1, 2, 10, 9, 3, 8, 11, 4, -1, ],
[ 4, 0, 8, 11, 3, 4, 1, 2, 10, 9, -1, ],
[ 5, 0, 2, 10, 9, 5, 3, 8, 11, 4, -1, ],
[ 7, 2, 10, 9, 5, 8, 11, 3, -1, ],
[ 3, 2, 3, 7, 3, 8, 11, 4, 3, 10, 9, 6, -1, ],
[ 5, 0, 8, 11, 7, 2, 3, 10, 9, 6, -1, ],
[ 3, 0, 1, 5, 3, 2, 3, 7, 3, 8, 11, 4, 3, 10, 9, 6, -1, ],
[ 6, 1, 5, 8, 11, 7, 2, 3, 10, 9, 6, -1, ],
[ 5, 1, 3, 7, 10, 9, 3, 8, 11, 4, -1, ],
[ 7, 0, 8, 11, 7, 10, 9, 1, -1, ],
[ 6, 0, 3, 7, 10, 9, 5, 3, 8, 11, 4, -1, ],
[ 6, 8, 11, 7, 10, 9, 5, -1, ],
[ 5, 5, 6, 10, 11, 4, -1, ],
[ 6, 0, 5, 6, 10, 11, 3, -1, ],
[ 6, 0, 1, 6, 10, 11, 4, -1, ],
[ 5, 1, 6, 10, 11, 3, -1, ],
[ 6, 1, 2, 10, 11, 4, 5, -1, ],
[ 7, 0, 5, 1, 2, 10, 11, 3, -1, ],
[ 5, 0, 2, 10, 11, 4, -1, ],
[ 4, 2, 10, 11, 3, -1, ],
[ 3, 2, 3, 7, 5, 5, 6, 10, 11, 4, -1, ],
[ 7, 0, 5, 6, 10, 11, 7, 2, -1, ],
[ 6, 0, 1, 6, 10, 11, 4, 3, 2, 3, 7, -1, ],
[ 6, 1, 6, 10, 11, 7, 2, -1, ],
[ 7, 1, 3, 7, 10, 11, 4, 5, -1, ],
[ 3, 0, 5, 1, 3, 10, 11, 7, -1, ],
[ 6, 0, 3, 7, 10, 11, 4, -1, ],
[ 3, 10, 11, 7, -1, ],
[ 4, 7, 11, 9, 6, -1, ],
[ 3, 0, 4, 3, 4, 7, 11, 9, 6, -1, ],
[ 3, 0, 1, 5, 4, 7, 11, 9, 6, -1, ],
[ 4, 1, 5, 4, 3, 4, 7, 11, 9, 6, -1, ],
[ 5, 1, 2, 7, 11, 9, -1, ],
[ 3, 0, 4, 3, 5, 1, 2, 7, 11, 9, -1, ],
[ 6, 0, 2, 7, 11, 9, 5, -1, ],
[ 7, 2, 7, 11, 9, 5, 4, 3, -1, ],
[ 5, 2, 3, 11, 9, 6, -1, ],
[ 6, 0, 4, 11, 9, 6, 2, -1, ],
[ 3, 0, 1, 5, 5, 2, 3, 11, 9, 6, -1, ],
[ 7, 1, 5, 4, 11, 9, 6, 2, -1, ],
[ 4, 1, 3, 11, 9, -1, ],
[ 5, 0, 4, 11, 9, 1, -1, ],
[ 5, 0, 3, 11, 9, 5, -1, ],
[ 4, 11, 9, 5, 4, -1, ],
[ 5, 6, 7, 11, 8, 5, -1, ],
[ 3, 0, 4, 3, 5, 6, 7, 11, 8, 5, -1, ],
[ 6, 0, 1, 6, 7, 11, 8, -1, ],
[ 7, 1, 6, 7, 11, 8, 4, 3, -1, ],
[ 6, 1, 2, 7, 11, 8, 5, -1, ],
[ 3, 0, 4, 3, 6, 1, 2, 7, 11, 8, 5, -1, ],
[ 5, 0, 2, 7, 11, 8, -1, ],
[ 6, 2, 7, 11, 8, 4, 3, -1, ],
[ 6, 2, 3, 11, 8, 5, 6, -1, ],
[ 7, 0, 4, 11, 8, 5, 6, 2, -1, ],
[ 7, 0, 1, 6, 2, 3, 11, 8, -1, ],
[ 3, 1, 6, 2, 3, 11, 8, 4, -1, ],
[ 5, 1, 3, 11, 8, 5, -1, ],
[ 6, 0, 4, 11, 8, 5, 1, -1, ],
[ 4, 0, 3, 11, 8, -1, ],
[ 3, 11, 8, 4, -1, ],
[ 5, 8, 9, 6, 7, 4, -1, ],
[ 6, 0, 8, 9, 6, 7, 3, -1, ],
[ 3, 0, 1, 5, 5, 8, 9, 6, 7, 4, -1, ],
[ 7, 1, 5, 8, 9, 6, 7, 3, -1, ],
[ 6, 1, 2, 7, 4, 8, 9, -1, ],
[ 7, 0, 8, 9, 1, 2, 7, 3, -1, ],
[ 7, 0, 2, 7, 4, 8, 9, 5, -1, ],
[ 3, 2, 7, 3, 3, 8, 9, 5, -1, ],
[ 6, 2, 3, 4, 8, 9, 6, -1, ],
[ 5, 0, 8, 9, 6, 2, -1, ],
[ 3, 0, 1, 5, 6, 2, 3, 4, 8, 9, 6, -1, ],
[ 6, 1, 5, 8, 9, 6, 2, -1, ],
[ 5, 1, 3, 4, 8, 9, -1, ],
[ 4, 0, 8, 9, 1, -1, ],
[ 6, 0, 3, 4, 8, 9, 5, -1, ],
[ 3, 8, 9, 5, -1, ],
[ 4, 5, 6, 7, 4, -1, ],
[ 5, 0, 5, 6, 7, 3, -1, ],
[ 5, 0, 1, 6, 7, 4, -1, ],
[ 4, 1, 6, 7, 3, -1, ],
[ 5, 1, 2, 7, 4, 5, -1, ],
[ 6, 0, 5, 1, 2, 7, 3, -1, ],
[ 4, 0, 2, 7, 4, -1, ],
[ 3, 2, 7, 3, -1, ],
[ 5, 2, 3, 4, 5, 6, -1, ],
[ 4, 0, 5, 6, 2, -1, ],
[ 6, 0, 1, 6, 2, 3, 4, -1, ],
[ 3, 1, 6, 2, -1, ],
[ 4, 1, 3, 4, 5, -1, ],
[ 3, 0, 5, 1, -1, ],
[ 3, 0, 3, 4, -1, ],
[ -1, ],
];const s_edgeSides : Array[int] = [
0, 1, 1, 2, 2, 3, 3, 0,
0, 5, 1, 4, 2, 7, 3, 6,
4, 5, 7, 4, 6, 7, 5, 6,
];
const s_vertexPositions : Array[Vector3i] = [
Vector3i(0, 0, 0),
Vector3i(1, 0, 0),
Vector3i(1, 1, 0),
Vector3i(0, 1, 0),
Vector3i(1, 0, 1),
Vector3i(0, 0, 1),
Vector3i(0, 1, 1),
Vector3i(1, 1, 1),
];
@export var m_size : Vector3i = Vector3i(2, 2, 2);
var m_grid : Array[float] = [];
var m_cap : float = 0.0;
####################################################################################
func _ready() -> void:
seed(SEED_HERE);
var noiseMap : FastNoiseLite = FastNoiseLite.new();
const noiseScale : float = 2.5;
## CHUNK INITIAL GENERATION
m_grid.resize(m_size.x * m_size.y * m_size.z);
var v : Vector3i;
var i : int = 0;
var noise : float;
for z in range(m_size.z):
v.z = z;
for y in range(m_size.y):
v.y = y ;
for x in range(m_size.x):
v.x = x;
noise = noiseMap.get_noise_2d((v.x as float) * noiseScale, (v.z as float) * noiseScale) + (2 - (v.y * 0.1));
m_grid[i] = clampf(noise, -1, 1);
i += 1;
updateMesh();
####################################################################################
## GENERAL ALGORITHM STARTS HERE
func updateMesh() -> void:
var vertices : PackedVector3Array = PackedVector3Array();
var indices : PackedInt32Array = PackedInt32Array();
var lookupIndex : int;
var lookupReadIndex : int;
var readCount : int;
## MESH DATA GENERATION
var v : Vector3i;
for x : int in range(m_size.x):
v.x = x;
for y : int in range(m_size.y):
v.y = y;
for z : int in range(m_size.z):
v.z = z;
# Get s_edgeLookup index.
lookupIndex = 0;
for i : int in range(len(s_vertexPositions)):
lookupIndex += (1 << i) if isWeightEnabled(v + s_vertexPositions[i]) else 0;
lookupReadIndex = 0;
while (s_edgeLookup[lookupIndex][lookupReadIndex] != -1):
# Read from s_edgeLookup table.
readCount = s_edgeLookup[lookupIndex][lookupReadIndex];
lookupReadIndex += 1;
if (readCount < 3):
continue;
# Triangle vertices.
var baseIndex : int = vertices.size();
var edge : int;
for i : int in range(readCount):
edge = s_edgeLookup[lookupIndex][lookupReadIndex + i];
vertices.push_back(getEdgePosition(edge, v));
lookupReadIndex += readCount;
# Triangle indices.
indices.append(baseIndex + 0);
indices.append(baseIndex + 1);
indices.append(baseIndex + 2);
for i : int in range(3, readCount):
indices.append(baseIndex + 0);
indices.append(baseIndex + i - 1);
indices.append(baseIndex + i);
## MESH UPLOAD
# Validation check.
if (vertices.size() < 2):
$Mesh.mesh = null;
$Collider.shape = null;
return;
# Clear mesh.
if ($Mesh.mesh is not ArrayMesh):
$Mesh.mesh = ArrayMesh.new();
$Mesh.mesh.clear_surfaces();
# Setup mesh.
var arrays = [];
arrays.resize(Mesh.ARRAY_MAX);
arrays[Mesh.ARRAY_VERTEX] = vertices;
arrays[Mesh.ARRAY_INDEX] = indices;
# Commit mesh.
$Mesh.mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arrays);
# Normals.
var surface_tool = SurfaceTool.new()
surface_tool.create_from($Mesh.mesh, 0)
surface_tool.generate_normals()
$Mesh.mesh = surface_tool.commit()
# Collider.
var collisionVertices : PackedVector3Array = PackedVector3Array();
for i in indices:
collisionVertices.append(vertices[i]);
var collider : ConcavePolygonShape3D = ConcavePolygonShape3D.new();
collider.set_faces(collisionVertices);
$Collider.shape = collider;
####################################################################################
func getWeight(pos : Vector3i) -> float:
# Border check
if (pos.x < 0 || pos.x >= m_size.x ||
pos.y < 0 || pos.y >= m_size.y ||
pos.z < 0 || pos.z >= m_size.z):
return 1.0; # (Default fill)
# Get weight.
var index : int = pos.x + (pos.y * m_size.x) + (pos.z * m_size.x * m_size.y);
return m_grid[index];
func isWeightEnabled(pos : Vector3i) -> bool:
return getWeight(pos) > m_cap;
func getEdgePosition(edgeIndex : int, pos : Vector3i) -> Vector3:
var v0 : int = s_edgeSides[(edgeIndex * 2) + 0];
var v1 : int = s_edgeSides[(edgeIndex * 2) + 1];
var p0 : Vector3i = pos + s_vertexPositions[v0];
var p1 : Vector3i = pos + s_vertexPositions[v1];
var w0 : float = getWeight(p0);
var w1 : float = getWeight(p1);
var w : float = (m_cap - w0) / (w1 - w0);
return (p0 as Vector3).lerp(p1 as Vector3, w);