/// <summary>
/// Generate a world chunk
/// </summary>
public void Setup(VoxelCache cache, Biome biome)
{
// Create lightweight voxel array. At 2 bits/voxel, Y axis shares 16 voxels per int
voxels = new uint[cache.SizeX, cache.SizeZ, cache.SizeY / 16];
cache.voxels.Remove(previousOffset);
cache.voxels.Add(offset,
new byte[cache.SizeX + 2, cache.SizeZ + 2, cache.SizeY + 2]);
// First generate the height map and dense voxel data
BuildVoxels(cache, biome);
state = ChunkState.VoxelsLoaded;
// Remove voxels from cache if chunk doesn't need a mesh
if (isEmpty || isCompletelySolid)
{
cache.voxels.Remove(offset);
}
// Reset cache
cache.ResetData();
}
/// <summary>
/// Calculate shading for all sides of a cube
/// </summary>
private float[] ComputeShade(VoxelCache cache, Biome biome, int neighbors, int x, int y, int z)
{
// Get shade contributions using a ray cast
float altShade = (float)(cache.lightVoxels[x, z, y] / 20f);
altShade = 1 - (float)Math.Pow(altShade, 1.25f);
// Get shade contributions using a ray cast
float[] shade = new float[6];
// Shade all the cube sides individually
for (int s = 0; s < shade.Length; s++)
{
// Start at full light
shade[s] = 1f;
float step = 3f / points[s].Length;
// Skipped sides that have neighbors
if ((neighbors & 1 << s) == 1)
{
continue;
}
for (int j = 0; j < points[s].Length; j++)
{
if (shade[s] <= 0.1f)
{
break;
}
bool found = false;
for (float i = 2.5f; i <= 10.5f; i += 1f)
{
if (found)
{
continue;
}
Vector3 newBlock;
int chunkIndex = 4;
newBlock.X = i * points[s][j].X + x;
newBlock.Y = i * points[s][j].Y + y;
newBlock.Z = i * points[s][j].Z + z;
int nx = (int)Math.Round(newBlock.X) - 1;
int ny = (int)Math.Round(newBlock.Y);
int nz = (int)Math.Round(newBlock.Z) - 1;
// Set the new voxel offset if ray enters another chunk
if (nx < 0)
{
chunkIndex--;
}
if (nz < 0)
{
chunkIndex -= 3;
}
if (nx >= cache.SizeX)
{
chunkIndex++;
}
if (nz >= cache.SizeZ)
{
chunkIndex += 3;
}
if (nx < 0)
{
nx += cache.SizeX;
}
if (nz < 0)
{
nz += cache.SizeZ;
}
if (nx >= cache.SizeX)
{
nx -= cache.SizeX;
}
if (nz >= cache.SizeZ)
{
nz -= cache.SizeZ;
}
// Continue if Y goes out of bounds
if (ny < 0 || ny >= cache.SizeY)
{
continue;
}
byte voxel = GetVoxel(nx, ny, nz);
if (chunkIndex != 4)
{
if (chunkIndex > 4)
{
chunkIndex--;
}
voxel = sideNeighbors[chunkIndex].GetVoxel(nx, ny, nz);
}
float falloff = 1f / i;
if (voxel != (byte)BlockType.Empty)
{
shade[s] -= (step * falloff);
found = true;
}
}
}
shade[s] = (altShade > shade[s]) ? shade[s] : altShade;
shade[s] = (shade[s] < 0.15f) ? 0.15f : shade[s];
}
return(shade);
}
/// <summary>
/// Second step in chunk generation
/// Add visible voxels to the list.
/// </summary>
private void FindVisible(VoxelCache cache, Biome biome)
{
// Assign temporary arrays for visible voxels
byte[, ,] visibleVoxels = new byte[cache.SizeX + 2, cache.SizeX + 2, cache.SizeY + 2];
byte[, ,] cacheVoxels = cache.voxels[offset];
Parallel.For(1, cache.SizeX + 1, x =>
{
for (int z = 0; z <= cache.SizeZ + 1; ++z)
{
// Get last shade for x, z location
byte shade = biome.lightMask[x, z];
bool shaded = (shade == 15);
for (int y = cache.SizeY + 1; y >= 0; --y)
{
byte voxel = cacheVoxels[x, z, y];
if (voxel != 0)
{
int neighbors = 0;
if (x == 0 || y == 0 || z == 0 ||
x == cache.SizeX + 1 || y == cache.SizeY + 1 || z == cache.SizeZ + 1)
{
visibleVoxels[x, z, y] = voxel;
}
else
{
// Immediate side neighbors
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z, y] > 0) << NeighborBlock.Middle_W;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z, y] > 0) << NeighborBlock.Middle_E;
neighbors |= Convert.ToInt32(cacheVoxels[x, z - 1, y] > 0) << NeighborBlock.Middle_N;
neighbors |= Convert.ToInt32(cacheVoxels[x, z + 1, y] > 0) << NeighborBlock.Middle_S;
// Check top and bottom
neighbors |= Convert.ToInt32(cacheVoxels[x, z, y - 1] > 0) << NeighborBlock.Bottom_Center;
neighbors |= Convert.ToInt32(cacheVoxels[x, z, y + 1] > 0) << NeighborBlock.Top_Center;
// Add to the visible list if not occluded on all sides
if (neighbors != 0x3f)
{
visibleVoxels[x, z, y] = voxel;
cache.visibleNeighbors[x - 1, z - 1, y - 1] = neighbors;
}
cache.lightVoxels[x, z, y] = shade;
shade = 8;
}
}
// Finish checking this voxel
if (y == 1)
{
biome.lightMask[x, z] = shade;
}
}
}
});
// Final voxel list is truncated
cache.voxels[offset] = visibleVoxels;
}
/// <summary>
/// Third step in chunk generation
/// Turn visible voxels into meshes
/// </summary>
private void BuildMesh(VoxelCache cache, Biome biome)
{
int nextVertex = 0;
int nextIndex = 0;
Object lockObject = new object();
// Initialize vertex and index data
VertexPositionColorNormal[] chunkVertices = new VertexPositionColorNormal[vertexMaxSize];
ushort[] chunkIndices = new ushort[indexMaxSize];
// Assign temp array
byte[, ,] cacheVoxels = cache.voxels[offset];
// Create the mesh cubes
Parallel.For(1, cache.SizeX + 1, x =>
{
for (int z = 1; z < cache.SizeZ + 1; ++z)
{
for (int y = 1; y < cache.SizeY + 1; ++y)
{
byte voxel = cacheVoxels[x, z, y];
if (nextIndex + 72 > indexMaxSize)
{
// Skip
break;
}
else if (voxel > 0)
{
int neighbors = cache.visibleNeighbors[x - 1, z - 1, y - 1];
// Get the corner and edge neighbors
// Top corners (bits 7-10)
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z - 1, y + 1] > 0) << NeighborBlock.Top_NW;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z - 1, y + 1] > 0) << NeighborBlock.Top_NE;
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z + 1, y + 1] > 0) << NeighborBlock.Top_SW;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z + 1, y + 1] > 0) << NeighborBlock.Top_SE;
// Top edges (bits 11-14)
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z, y + 1] > 0) << NeighborBlock.Top_W;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z, y + 1] > 0) << NeighborBlock.Top_E;
neighbors |= Convert.ToInt32(cacheVoxels[x, z - 1, y + 1] > 0) << NeighborBlock.Top_N;
neighbors |= Convert.ToInt32(cacheVoxels[x, z + 1, y + 1] > 0) << NeighborBlock.Top_S;
// Bottom corners (bits 15-18)
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z - 1, y - 1] > 0) << NeighborBlock.Bottom_NW;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z - 1, y - 1] > 0) << NeighborBlock.Bottom_NE;
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z + 1, y - 1] > 0) << NeighborBlock.Bottom_SW;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z + 1, y - 1] > 0) << NeighborBlock.Bottom_SE;
// Bottom edges (bits 19-22)
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z, y - 1] > 0) << NeighborBlock.Bottom_W;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z, y - 1] > 0) << NeighborBlock.Bottom_E;
neighbors |= Convert.ToInt32(cacheVoxels[x, z - 1, y - 1] > 0) << NeighborBlock.Bottom_N;
neighbors |= Convert.ToInt32(cacheVoxels[x, z + 1, y - 1] > 0) << NeighborBlock.Bottom_S;
// Middle side corners (bits 23-26)
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z - 1, y] > 0) << NeighborBlock.Middle_NW;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z - 1, y] > 0) << NeighborBlock.Middle_NE;
neighbors |= Convert.ToInt32(cacheVoxels[x - 1, z + 1, y] > 0) << NeighborBlock.Middle_SW;
neighbors |= Convert.ToInt32(cacheVoxels[x + 1, z + 1, y] > 0) << NeighborBlock.Middle_SE;
// Set the cube color and shade
uint color = biome.GetBlockColor((BlockType)voxel, (int)(x + Offset.X), y, (int)(z + Offset.Z));
float[] shade = ComputeShade(cache, biome, neighbors, x, y, z);
// Add the cube
Cube cube = new Cube(new Vector3(x, y, z), color, shade, neighbors);
lock (lockObject)
{
// Point next index value to number of vertices
int indexOffset = nextVertex;
for (int v = 0; v < cube.Vertices.Length; v++)
{
chunkVertices[nextVertex++] = cube.Vertices[v];
}
for (int i = 0; i < cube.Indices.Length; i++)
{
chunkIndices[nextIndex++] = (ushort)(indexOffset + cube.Indices[i]);
}
}
}
// Finish adding cube for this voxel
}
}
});
// Create a mesh
mesh = new MeshData();
// Create bounding box
mesh.bBox = new BoundingBox(extents[0], extents[1]);
if (nextIndex > 0)
{
// Create vertex and index buffers
mesh.vb = new VertexBuffer(
graphicsDevice,
VertexPositionColorNormal.VertexDeclaration,
nextVertex,
BufferUsage.None
);
mesh.ib = new IndexBuffer(
graphicsDevice, IndexElementSize.SixteenBits,
(ushort)nextIndex,
BufferUsage.None
);
// Set up vertex and index buffer
mesh.vb.SetData(chunkVertices, 0, nextVertex);
mesh.ib.SetData(chunkIndices, 0, nextIndex);
}
// Finished building meshes
}
/// <summary>
/// First step in voxel chunk generation
/// This could be used to get voxel data only (when mesh is not needed)
/// </summary>
private void BuildVoxels(VoxelCache cache, Biome biome)
{
// Generate the dense voxel data
Parallel.For(0, cache.SizeX + 2, x =>
{
for (int z = 0; z < cache.SizeX + 2; ++z)
{
//float slope = heightMap.CalculateSlope(x, z);
cache.heightValues[x, z] = biome.SourceHeight[x, z];
int yHeight = (int)cache.heightValues[x, z];
// Add some rivers
bool riverbed = false;
// Create an alternate height for river banks.
// Higher altitudes will have narrower streams
float maxRiverHeight = 120f;
// Create noise for the river depths
float noise = Noise.Simplex.Generate(
(float)(((offset.X + x) / (float)(noiseRes * 24f)) + 200f),
(float)(((offset.Z + z) / (float)(noiseRes * 24f)) + 200f));
noise += Noise.Simplex.Generate(
(float)(((offset.X + x) / (noiseRes * 4f)) + 200f),
(float)(((offset.Z + z) / (noiseRes * 4f)) + 200f)) / 5f;
noise += Noise.Simplex.Generate(
(float)(((offset.X + x) / (noiseRes / 2f)) + 200f),
(float)(((offset.Z + z) / (noiseRes / 2f)) + 200f)) / 50f;
noise *= MathHelper.Lerp(0, 1.5f, yHeight / maxRiverHeight);
noise = (float)Math.Pow(Math.Abs(noise), 0.7f);
// Increase humidity around river areas
float riverDepth = MathHelper.Lerp(0.8f, 0.98f,
(yHeight > maxRiverHeight) ? 1 : yHeight / maxRiverHeight);
float surfaceHeight = cache.heightValues[x, z];
// Set depth of river beds
float maxRiverBankNoise = 0.10f;
if (noise >= 0.05f && noise < maxRiverBankNoise && yHeight < maxRiverHeight)
{
surfaceHeight -= (0.03f - (noise - 0.05f)) * 50f;
surfaceHeight--;
}
// Set the water level
float riverWaterLevel = surfaceHeight - (maxRiverBankNoise - 0.05f) * 100f;
riverWaterLevel++;
if (noise < 0.05f && yHeight < maxRiverHeight)
{
riverbed = true;
surfaceHeight = (int)(yHeight * riverDepth);
surfaceHeight--;
}
// Add plateau height, first by setting a maximum height
float noise2 = Noise.Simplex.Generate(
(float)(((offset.X + x) / (float)(noiseRes * 5f)) + 200f),
(float)(((offset.Z + z) / (float)(noiseRes * 3.2f)) + 200f));
noise2 += Noise.Simplex.Generate(
(float)(((offset.X + x) / (float)(noiseRes * 1.6f)) + 200f),
(float)(((offset.Z + z) / (float)(noiseRes * 2)) + 200f)) / 5f;
float plateauRange = 50f;
int plateauHeight = (int)((noise2 / 2f + 0.5f) * plateauRange);
plateauHeight += 70;
for (int y = 0; y < cache.SizeY + 2; ++y)
{
// Get voxels from height indexes
BlockType block = BlockType.Empty;
// Add block type depending on relation to surface
if (y + offset.Y < (int)surfaceHeight)
{
block = BlockType.Surface;
}
if (riverbed && y + offset.Y < riverWaterLevel)
{
block = BlockType.Water;
}
if (y + offset.Y == (int)surfaceHeight && y + offset.Y < yHeight)
{
block = BlockType.Surface;
}
// Add actual plateau blocks here
if (y + offset.Y >= yHeight && y + offset.Y <= plateauHeight)
{
noise2 = Noise.Simplex.Generate(
(float)(((offset.X + x) / (noiseRes * 1.5f)) + 200f),
(float)(((offset.Y + y) / (noiseRes * 3f)) + 200f),
(float)(((offset.Z + z) / (noiseRes * 1.25f)) + 200f));
noise2 += Noise.Simplex.Generate(
(float)(((offset.X + x) / (noiseRes / 1.5f)) + 200f),
(float)(((offset.Y + y) / (noiseRes)) + 200f),
(float)(((offset.Z + z) / (noiseRes / 1.25f)) + 200f)) / 5f;
noise2 += Noise.Simplex.Generate(
(float)(((offset.X + x) / (noiseRes / 5f)) + 200f),
(float)(((offset.Y + y) / (noiseRes / 2f)) + 200f),
(float)(((offset.Z + z) / (noiseRes / 5f)) + 200f)) / 10f;
// Adjust plateau height around rivers
float threshold = 0.3f;
if (noise < maxRiverBankNoise * 3f)
{
noise2 *= (float)Math.Pow((noise / (maxRiverBankNoise * 3f)), 0.5);
}
if (noise2 > threshold)
{
// Inner blocks
block = BlockType.Dirt;
if (y + offset.Y == plateauHeight)
{
block = BlockType.Surface;
}
}
}
// Set upper and lower bounds
if (block != BlockType.Empty)
{
cache.voxels[offset][x, z, y] = (byte)block;
isEmpty = false;
}
else if (isCompletelySolid)
{
isCompletelySolid = false;
}
}
// Finished updating this voxel
}
});
// Add extra objects to the surface such as trees
for (int i = 0; i < 9; i++)
{
int x = i / 3 - 1;
int z = i % 3 - 1;
GenerateExtraObjects(biome, cache, x, z);
}
// Set lightweight voxel data for collisions/physics
Parallel.For(1, cache.SizeX + 1, x =>
{
for (int z = 1; z < cache.SizeZ + 1; ++z)
{
for (int y = 0; y < cache.SizeY; ++y)
{
int voxelY = y / 16;
int voxelBits = (y % 16) * 2;
uint voxel = voxels[x - 1, z - 1, voxelY];
// Add 1 to voxel data
BlockType block = (BlockType)cache.voxels[offset][x, z, y];
if (block != BlockType.Empty)
{
voxel = voxel | ((uint)1 << voxelBits);
}
voxels[x - 1, z - 1, voxelY] = voxel;
}
}
});
// Set bounding box extents
extents[0] = new Vector3(offset.X, offset.Y, offset.Z);
extents[1] = new Vector3(offset.X + cache.SizeX, offset.Y + cache.SizeY, offset.Z + cache.SizeX);
// Create temp mesh and bounding box
mesh = new MeshData();
mesh.bBox = new BoundingBox(extents[0], extents[1]);
}