/// <summary>
/// Sets the density value at a given point, if it is inside the chunk.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="z"></param>
/// <param name="value"></param>
public void SetValueAtPoint(int x, int y, int z, float value)
{
if (0 <= x && x < VoxelUtilities.pointsPerAxis && 0 <= y && y < VoxelUtilities.pointsPerAxis && 0 <= z && z < VoxelUtilities.pointsPerAxis)
{
points[VoxelUtilities.GetIndex(x, y, z)] = Mathf.Clamp01(value);
}
}
/// <summary>
/// Adds to the density value at a given point, if it is inside the chunk.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="z"></param>
/// <param name="amount"></param>
public void AddValueAtPoint(int x, int y, int z, float amount)
{
if (0 <= x && x < VoxelUtilities.pointsPerAxis && 0 <= y && y < VoxelUtilities.pointsPerAxis && 0 <= z && z < VoxelUtilities.pointsPerAxis)
{
points[VoxelUtilities.GetIndex(x, y, z)] += amount;
}
}
/// <summary>
/// Returns the density value at a given point. If the point is outside the chunk,
/// then we return 1 (i.e solid). TODO: Allow Chunks to retrieve values from neigh-
/// bouring chunks.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="z"></param>
/// <returns>Density value at the specified point.</returns>
public float GetValueAtPoint(int x, int y, int z)
{
if (0 <= x && x < VoxelUtilities.pointsPerAxis && 0 <= y && y < VoxelUtilities.pointsPerAxis && 0 <= z && z < VoxelUtilities.pointsPerAxis)
{
return(points[VoxelUtilities.GetIndex(x, y, z)]);
}
else
{
return(1f);
}
}
/// <summary>
/// Generates the initial density values representing the terrain.
/// </summary>
void GetPoints()
{
points = new float[VoxelUtilities.pointsPerAxis * VoxelUtilities.pointsPerAxis * VoxelUtilities.pointsPerAxis];
//for (int z = 6; z < pointsPerAxis - 6; z++)
//{
// for (int y = 14; y < pointsPerAxis -1; y++)
// {
// for (int x = 6; x < pointsPerAxis - 6; x++)
// {
// points[z * pointsPerAxisSqr + y * pointsPerAxis + x] = y < pointsPerAxis - 3 ? 0 : 1f;
// }
// }
//}
points[VoxelUtilities.GetIndex(8, 14, 8)] = 1f;
}
/// <summary>
/// Runs on a worker thread. This method applies the Marching Cubes algorithm to
/// extract a surface at the specified ISO-value.
/// </summary>
/// <param name="isoValue"></param>
/// <returns>Returns prepared MeshData.</returns>
VoxelUtilities.MeshData GenerateChunk(float isoValue = 0.5f)
{
// If points have not been generated, or the points are to be reset,
// then call the GetPoints method.
if (!pointsHaveBeenGenerated)
{
GetPoints();
pointsHaveBeenGenerated = true;
}
// A list to store the Triangles
List <VoxelUtilities.Triangle> triangles = new List <VoxelUtilities.Triangle>();
// March through the 3D density values grid.
for (int z = 0; z < VoxelUtilities.chunkSize; z++)
{
for (int y = 0; y < VoxelUtilities.chunkSize; y++)
{
for (int x = 0; x < VoxelUtilities.chunkSize; x++)
{
// Get the vertices and values at the 8 corners of the cube.
VoxelUtilities.CubeCorner[] cubeCorners =
{
VoxelUtilities.GetCubeCorner(x, y, z, points),
VoxelUtilities.GetCubeCorner(x + 1, y, z, points),
VoxelUtilities.GetCubeCorner(x + 1, y, z + 1, points),
VoxelUtilities.GetCubeCorner(x, y, z + 1, points),
VoxelUtilities.GetCubeCorner(x, y + 1, z, points),
VoxelUtilities.GetCubeCorner(x + 1, y + 1, z, points),
VoxelUtilities.GetCubeCorner(x + 1, y + 1, z + 1, points),
VoxelUtilities.GetCubeCorner(x, y + 1, z + 1, points)
};
// Calculate the configuration number (256 possibilities)
int configNumber = 0;
for (int i = 0; i < 8; i++)
{
if (cubeCorners[i].value > isoValue)
{
configNumber |= (int)Mathf.Pow(2, i);
}
}
// Add triangles according to the predefined triangulation for the specified configuration
for (int i = 0; VoxelUtilities.triangulation[configNumber][i] != -1; i += 3)
{
int a0 = VoxelUtilities.cornerIndexAFromEdge[VoxelUtilities.triangulation[configNumber][i]];
int b0 = VoxelUtilities.cornerIndexBFromEdge[VoxelUtilities.triangulation[configNumber][i]];
int a1 = VoxelUtilities.cornerIndexAFromEdge[VoxelUtilities.triangulation[configNumber][i + 1]];
int b1 = VoxelUtilities.cornerIndexBFromEdge[VoxelUtilities.triangulation[configNumber][i + 1]];
int a2 = VoxelUtilities.cornerIndexAFromEdge[VoxelUtilities.triangulation[configNumber][i + 2]];
int b2 = VoxelUtilities.cornerIndexBFromEdge[VoxelUtilities.triangulation[configNumber][i + 2]];
VoxelUtilities.Triangle tri;
tri.a = VoxelUtilities.InterpolateVerts(cubeCorners[a0], cubeCorners[b0], isoValue);
tri.b = VoxelUtilities.InterpolateVerts(cubeCorners[a1], cubeCorners[b1], isoValue);
tri.c = VoxelUtilities.InterpolateVerts(cubeCorners[a2], cubeCorners[b2], isoValue);
tri.color = Color.white;
triangles.Add(tri);
}
}
}
}
// Prepare MeshData from the triangles List
int triangleCount = triangles.Count;
List <Vector3> vertices = new List <Vector3>();
List <Color> colors = new List <Color>();
int[] tris = new int[triangleCount * 3];
////Smooth shading
//Dictionary<Vector3, int> vertexToIndex = new Dictionary<Vector3, int>();
for (int i = 0; i < triangleCount; i++)
{
for (int j = 0; j < 3; j++)
{
////Smooth shading
//Vector3 vertex = triangles[i][j];
//Color color = triangles[i].color;
//if (vertexToIndex.ContainsKey(vertex))
//{
// tris[i * 3 + j] = vertexToIndex[vertex];
//} else
//{
// vertices.Add(vertex);
// colors.Add(color);
// int index = vertexToIndex.Count;
// vertexToIndex.Add(vertex, index);
// tris[i * 3 + j] = index;
//}
// Flat shading
tris[i * 3 + j] = i * 3 + j;
vertices.Add(triangles[i][j]);
colors.Add(triangles[i].color);
}
}
VoxelUtilities.MeshData meshData;
meshData.vertices = vertices.ToArray();
meshData.colors = colors.ToArray();
meshData.triangles = tris;
return(meshData);
}
