internal void PolygonizeCell(Vector3i offsetPos, Vector3i pos, ref Mesh mesh, int lod)
{
offsetPos += pos * lod;
sbyte[] density = new sbyte[8];
for (int i = 0; i < density.Length; i++)
{
density [i] = volume [offsetPos + Tables.CornerIndex [i] * lod];
}
byte caseCode = (byte)((density [0] >> 7 & 0x01)
| (density [1] >> 6 & 0x02)
| (density [2] >> 5 & 0x04)
| (density [3] >> 4 & 0x08)
| (density [4] >> 3 & 0x10)
| (density [5] >> 2 & 0x20)
| (density [6] >> 1 & 0x40)
| (density [7] & 0x80));
if ((caseCode ^ ((density [7] >> 7) & 0xFF)) != 0)
{
byte regCellClass = Tables.RegularCellClass [caseCode];
ushort[] vertexLocations = Tables.RegularVertexData [caseCode];
Tables.RegularCell c = Tables.RegularCellData [regCellClass];
long triangleCount = c.GetTriangleCount();
byte[] indexOffset = c.Indizes(); //index offsets for current cell //array with real indizes for current cell
for (int i = 0; i < c.GetVertexCount(); i++)
{
byte edge = (byte)(vertexLocations [i] & 0xFF);
byte v0 = (byte)((edge >> 4) & 0x0F); //First Corner Index
byte v1 = (byte)(edge & 0x0F); //Second Corner Index
sbyte d0 = density [v0];
sbyte d1 = density [v1];
int t = (d1 << 8) / (d1 - d0);
int u = 0x0100 - t;
Vector3 P0 = (offsetPos + Tables.CornerIndex [v0] * lod).ToVector3();
Vector3 P1 = (offsetPos + Tables.CornerIndex [v1] * lod).ToVector3();
Vector3 Q = (t * P0 + u * P1) / 256f;
vertices.Add(Q);
mappedIndizes [i] = (ushort)(vertices.Count - 1);
}
for (int t = 0; t < c.GetTriangleCount(); t++)
{
for (int i = 0; i < 3; i++)
{
triangles.Add(mappedIndizes [indexOffset [t * 3 + i]]);
}
}
}
}
internal void PolygonizeCell(Vector3i offsetPos, Vector3i pos, ref Mesh mesh, int lod)
{
Debug.Assert(lod >= 1, "Level of Detail must be greater than 1");
offsetPos += pos * lod;
byte directionMask = (byte)((pos.X > 0 ? 1 : 0) | ((pos.Z > 0 ? 1 : 0) << 1) | ((pos.Y > 0 ? 1 : 0) << 2));
sbyte[] density = new sbyte[8];
for (int i = 0; i < density.Length; i++)
{
density[i] = volume[offsetPos + Tables.CornerIndex[i] * lod];
}
byte caseCode = getCaseCode(density);
if ((caseCode ^ ((density[7] >> 7) & 0xFF)) == 0) //for this cases there is no triangulation
{
return;
}
Vector3f[] cornerNormals = new Vector3f[8];
for (int i = 0; i < 8; i++)
{
var p = offsetPos + Tables.CornerIndex[i] * lod;
float nx = (volume[p + Vector3i.UnitX] - volume[p - Vector3i.UnitX]) * 0.5f;
float ny = (volume[p + Vector3i.UnitY] - volume[p - Vector3i.UnitY]) * 0.5f;
float nz = (volume[p + Vector3i.UnitZ] - volume[p - Vector3i.UnitZ]) * 0.5f;
//cornerNormals[i] = new Vector3f(nx, ny, nz);
cornerNormals[i].X = nx;
cornerNormals[i].Y = ny;
cornerNormals[i].Z = nz;
cornerNormals[i].Normalize();
}
byte regularCellClass = Tables.RegularCellClass[caseCode];
ushort[] vertexLocations = Tables.RegularVertexData[caseCode];
Tables.RegularCell c = Tables.RegularCellData[regularCellClass];
long vertexCount = c.GetVertexCount();
long triangleCount = c.GetTriangleCount();
byte[] indexOffset = c.Indizes(); //index offsets for current cell
ushort[] mappedIndizes = new ushort[indexOffset.Length]; //array with real indizes for current cell
for (int i = 0; i < vertexCount; i++)
{
byte edge = (byte)(vertexLocations[i] >> 8);
byte reuseIndex = (byte)(edge & 0xF); //Vertex id which should be created or reused 1,2 or 3
byte rDir = (byte)(edge >> 4); //the direction to go to reach a previous cell for reusing
byte v1 = (byte)((vertexLocations[i]) & 0x0F); //Second Corner Index
byte v0 = (byte)((vertexLocations[i] >> 4) & 0x0F); //First Corner Index
sbyte d0 = density[v0];
sbyte d1 = density[v1];
//Vector3f n0 = cornerNormals[v0];
//Vector3f n1 = cornerNormals[v1];
Debug.Assert(v1 > v0);
int t = (d1 << 8) / (d1 - d0);
int u = 0x0100 - t;
float t0 = t / 256f;
float t1 = u / 256f;
int index = -1;
if (UseCache && v1 != 7 && (rDir & directionMask) == rDir)
{
Debug.Assert(reuseIndex != 0);
ReuseCell cell = cache.GetReusedIndex(pos, rDir);
index = cell.Verts[reuseIndex];
}
if (index == -1)
{
Vector3f normal = cornerNormals[v0] * t0 + cornerNormals[v1] * t1;
GenerateVertex(ref offsetPos, ref pos, mesh, lod, t, ref v0, ref v1, ref d0, ref d1, normal);
index = mesh.LatestAddedVertIndex();
}
if ((rDir & 8) != 0)
{
cache.SetReusableIndex(pos, reuseIndex, mesh.LatestAddedVertIndex());
}
mappedIndizes[i] = (ushort)index;
}
for (int t = 0; t < triangleCount; t++)
{
for (int i = 0; i < 3; i++)
{
mesh.AddIndex(mappedIndizes[c.Indizes()[t * 3 + i]]);
}
}
}
private static void PolygonizeCell(Vector3i pos, sbyte[] density, MeshBuilder mesh, int lod)
{
byte directionMask = (byte)((pos.x > 0 ? 1 : 0) | ((pos.z > 0 ? 1 : 0) << 1) | ((pos.y > 0 ? 1 : 0) << 2));
byte caseCode = GetCaseCode(density);
if ((caseCode ^ ((density[7] >> 7) & 0xFF)) == 0) //for this cases there is no triangulation
{
return;
}
byte regularCellClass = Tables.RegularCellClass[caseCode];
ushort[] vertexLocations = Tables.RegularVertexData[caseCode];
Tables.RegularCell c = Tables.RegularCellData[regularCellClass];
long vertexCount = c.GetVertexCount();
long triangleCount = c.GetTriangleCount();
byte[] indexOffset = c.GetIndices(); // index offsets for current cell
int[] mappedIndices = new int[indexOffset.Length];
for (int i = 0; i < vertexCount; ++i)
{
byte edge = (byte)(vertexLocations[i] >> 8);
byte reuseIndex = (byte)(edge & 0xF); // vertex id which should be created or reused 1,2 or 3
byte rDir = (byte)(edge >> 4); // the direction to go to reach a previous cell for reusing
byte v0 = (byte)((vertexLocations[i] >> 4) & 0x0F); // first corner index
byte v1 = (byte)((vertexLocations[i]) & 0x0F); // second corner index
sbyte d0 = density[v0];
sbyte d1 = density[v1];
Debug.Assert(v1 > v0);
int t = (d1 << 8) / (d1 - d0);
int u = 0x0100 - t;
float t0 = t / 256f;
float t1 = u / 256f;
int index = -1;
// todo: try the caching stuff later
if (index == -1)
{
Vector3 p0 = new Vector3(
pos.x + Tables.vertexOffset[v0, 0],
pos.y + Tables.vertexOffset[v0, 1],
pos.z + Tables.vertexOffset[v0, 2]);
Vector3 p1 = new Vector3(
pos.x + Tables.vertexOffset[v1, 0],
pos.y + Tables.vertexOffset[v1, 1],
pos.z + Tables.vertexOffset[v1, 2]);
mesh.AddVertex(InterpolateVoxelVector(t, p0, p1));
}
mappedIndices[i] = index;
}
}
