I’m trying to generate Terrain using the marching cubes algorithm and some 3D noise. For optimization purposes i’m trying to split the world into chunks. My problem now is that the edges create little holes between the chunks.
Here is my code
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class NoiseTerrain : MonoBehaviour
{
[Range(1, 30)]
public int chunkresolution = 11;
public int chunksize = 1;
Noise noise = new Noise();
[Range(0, 1)]
public float threshhold = 0.6f;
public Vector3 offset = new Vector3(0, 0, 5);
TriAngulationTable tri = new TriAngulationTable();
[Range(0.01f, 10f)]
public float frequenzy = 2f;
public float amplitude = 1f;
int[,,] noisevalues;
public Material mat;
List<Vector3> verticeslist = new List<Vector3>(); //only for debugging make class list after finising
List<int> triangleslist = new List<int>(); //same here
public float accuracy;
int x = 0;
int y = 0;
int z = 0;
private float density(Vector3 point1)
{
return (noise.Evaluate(point1 / (chunkresolution - 1) * frequenzy + gameObject.transform.position/chunksize) + 1 )/2;
}
private void triangulate(int[,,] noisevalues)
{
string binary = "";
binary += noisevalues[x + 1, y, z + 1].ToString();
binary += noisevalues[x, y, z + 1].ToString(); ;
binary += noisevalues[x, y, z].ToString();
binary += noisevalues[x + 1, y, z].ToString();
binary += noisevalues[x + 1, y + 1, z + 1].ToString();
binary += noisevalues[x, y + 1, z + 1].ToString();
binary += noisevalues[x, y + 1, z].ToString();
binary += noisevalues[x + 1, y + 1, z].ToString();
int verticescount = 0;
for (int i = 0; i < 16; i++)
{
int index = tri.triTable[System.Convert.ToInt32(binary, 2), i];
if (index != -1)
{
Vector3 point1 = (tri.edgetable[index, 0] + new Vector3(x, y, z));
Vector3 point2 = (tri.edgetable[index, 1] + new Vector3(x,y,z));
float v1 = density(point1);
float v2 = density(point2);
float t = (threshhold-v1) / (v2-v1);
Vector3 newp;
newp = point1 + t * (point2-point1);
//newp = (point1 + point2) / 2;
verticeslist.Add(newp / (chunkresolution-1));
verticescount++;
/* GameObject sphere = GameObject.CreatePrimitive(PrimitiveType.Sphere);
sphere.transform.position = newp / (chunkresolution - 1) + gameObject.transform.position;
sphere.transform.localScale = new Vector3(0.01f, 0.01f, 0.01f);*/
}
}
for (int i = 0; i < verticescount; i++)
{
triangleslist.Add(verticeslist.Count - verticescount + i);
}
}
private void Update()
{
int[,,] noisevalues = new int[chunkresolution, chunkresolution, chunkresolution];
triangleslist.Clear();
verticeslist.Clear();
if (gameObject.GetComponent<MeshRenderer>() == null) { gameObject.AddComponent<MeshRenderer>(); }
if (gameObject.GetComponent<MeshFilter>() == null) { gameObject.AddComponent<MeshFilter>(); }
//filling the 3d array with the noisevalues
for (int x = 0; x < chunkresolution ; x++) //by adding the minus the borders are rendered
{
for (int y = 0; y < chunkresolution; y++)
{
for (int z = 0; z < chunkresolution; z++)
{
float noisevalue = density(new Vector3(x, y, z));
if ( noisevalue > threshhold)
{
noisevalues[x, y, z] = 1;
/* GameObject sphere = GameObject.CreatePrimitive(PrimitiveType.Sphere);
sphere.transform.position = new Vector3(x, y, z) / (chunkresolution - 1) + gameObject.transform.position;
sphere.transform.localScale = new Vector3(0.01f, 0.01f, 0.01f);*/
}
else
{
noisevalues[x, y, z] = 0;
}
}
}
}
for (z = 0; z < chunkresolution - 1; z++)
{
for (y = 0; y < chunkresolution - 1; y++)
{
for (x = 0; x < chunkresolution - 1; x++)
{
triangulate(noisevalues);
}
}
}
Mesh mesh = new Mesh();
mesh.Clear();
//if mesh gets to
mesh.indexFormat = UnityEngine.Rendering.IndexFormat.UInt32;
Vector3[] verticesarray = new Vector3[verticeslist.Count];
int[] trianglesarray = new int[triangleslist.Count];
verticesarray = verticeslist.ToArray();
trianglesarray = triangleslist.ToArray();
mesh.vertices = verticesarray;
mesh.triangles = trianglesarray;
mesh.RecalculateNormals();
gameObject.GetComponent<MeshFilter>().mesh = mesh;
gameObject.transform.localScale = new Vector3(chunksize, chunksize, chunksize);
gameObject.GetComponent<MeshRenderer>().material = mat;
}
}
. I might be completely wrong because i did not fully understand your response, meshes do connect occasionally. If I just draw a flat surface they match perfectly. Only if i change the points position using a noise function the chunks dont add up correctly. Maybe you can see this in the picture. I made sure that all my meshes have exactly the size 1. So i dont know where i should fit another small mesh between two chunks.