int CreateMarchingCube(Voxel v)
{
if (v == null)
{
return(0);
}
//allows us to track if the mesh is dirty and needs updating
//needs to be above the early exit checks, otherwise cells
//keep getting marked as dirty
v.lastMeshedValue = v.value;
//keep the meshing within the volume bounds
if (v.xID >= divisions)
{
return(0);
}
if (v.yID >= divisions)
{
return(0);
}
if (v.zID >= divisions)
{
return(0);
}
if (v.xID < 0)
{
return(0);
}
if (v.yID < 0)
{
return(0);
}
if (v.zID < 0)
{
return(0);
}
Voxel v0 = v;
//this conditions te input to the polygonize, and make sure all the neighbors have valid entries
//if all input voxels are gauranteed to not be edge voxels, this may not be necessary.
Voxel v1 = QueryVoxel(v.xID + 1, v.yID, v.zID);
if (v1 == null)
{
voxelBuffer[1].value = initialVoxelValue;
voxelBuffer[1].anchor = v.anchor + new Vector3(v.size.x, 0, 0);
v1 = voxelBuffer[1];
}
Voxel v2 = QueryVoxel(v.xID + 1, v.yID + 1, v.zID);
if (v2 == null)
{
voxelBuffer[2].value = initialVoxelValue;
voxelBuffer[2].anchor = v.anchor + new Vector3(v.size.x, v.size.y, 0);
v2 = voxelBuffer[2];
}
Voxel v3 = QueryVoxel(v.xID, v.yID + 1, v.zID);
if (v3 == null)
{
voxelBuffer[3].value = initialVoxelValue;
voxelBuffer[3].anchor = v.anchor + new Vector3(0, v.size.y, 0);
v3 = voxelBuffer[3];
}
Voxel v4 = QueryVoxel(v.xID, v.yID, v.zID + 1);
if (v4 == null)
{
voxelBuffer[4].value = initialVoxelValue;
voxelBuffer[4].anchor = v.anchor + new Vector3(0, 0, v.size.z);
v4 = voxelBuffer[4];
}
Voxel v5 = QueryVoxel(v.xID + 1, v.yID, v.zID + 1);
if (v5 == null)
{
voxelBuffer[5].value = initialVoxelValue;
voxelBuffer[5].anchor = v.anchor + new Vector3(v.size.x, 0, v.size.z);
v5 = voxelBuffer[5];
}
Voxel v6 = QueryVoxel(v.xID + 1, v.yID + 1, v.zID + 1);
if (v6 == null)
{
voxelBuffer[6].value = initialVoxelValue;
voxelBuffer[6].anchor = v.anchor + new Vector3(v.size.x, v.size.y, v.size.z);
v6 = voxelBuffer[6];
}
Voxel v7 = QueryVoxel(v.xID, v.yID + 1, v.zID + 1);
if (v7 == null)
{
voxelBuffer[7].value = initialVoxelValue;
voxelBuffer[7].anchor = v.anchor + new Vector3(0, v.size.y, v.size.z);
v7 = voxelBuffer[7];
}
int triangleStart = triangles.Count;
int createdTriangles = Polygonizer.Process(isolevel,
v0.value,
v1.value,
v2.value,
v3.value,
v4.value,
v5.value,
v6.value,
v7.value,
v0.anchor,
v1.anchor,
v2.anchor,
v3.anchor,
v4.anchor,
v5.anchor,
v6.anchor,
v7.anchor,
ref vertices, ref triangles);
//compute per vertex normal
int addedVertCount = 0;
while (normals.Count < vertices.Count)
{
normals.Add(new Vector3(0, 1, 0));
uvs.Add(new Vector2(-1, -1));
addedVertCount++;
}
for (int i = triangleStart; i < triangles.Count; i += 3)
{
v.trianglesIndicies.Add(i); //add it to each voxel this impacted?
int ia = triangles[i];
int ib = triangles[i + 1];
int ic = triangles[i + 2];
Vector3 a = vertices[ia];
Vector3 b = vertices[ib];
Vector3 c = vertices[ic];
Vector3 n = Vector3.Cross(a - b, b - c).normalized;
normals[ia] = n;
normals[ib] = n;
normals[ic] = n;
CalculateUVs(ia, ib, ic);
}
//adjust per voxel normal
return(createdTriangles);
}
/// <summary>
/// For a given voxel, execute the polygonization algorithm to generate mesh vertices, triangles, normals, and UVs.
/// </summary>
/// <param name="v">The voxel to mesh.</param>
/// <returns>Number of created triangles.</returns>
private int Polygonize(Voxel v)
{
if (v == null)
{
return(0);
}
// allows us to track if the mesh is dirty and needs updating
// needs to be above the early exit checks, otherwise voxels
// keep getting marked as dirty
v.lastMeshedValue = v.value;
// keep the meshing within the volume bounds
if (v.xID >= m_voxelResolution)
{
return(0);
}
if (v.yID >= m_voxelResolution)
{
return(0);
}
if (v.zID >= m_voxelResolution)
{
return(0);
}
if (v.xID < 0)
{
return(0);
}
if (v.yID < 0)
{
return(0);
}
if (v.zID < 0)
{
return(0);
}
Voxel v0 = v;
// this conditions te input to the polygonize, and make sure all the neighbors have valid entries
// if all input voxels are gauranteed to not be edge voxels, this may not be necessary.
// OPIMTIZATION - voxel can store meshing neighbors, rather than query each
// skip if they are null
Voxel v1 = QueryVoxel(v.xID + 1, v.yID, v.zID);
if (v1 == null)
{
return(0);
}
Voxel v2 = QueryVoxel(v.xID + 1, v.yID + 1, v.zID);
if (v2 == null)
{
return(0);
}
Voxel v3 = QueryVoxel(v.xID, v.yID + 1, v.zID);
if (v3 == null)
{
return(0);
}
Voxel v4 = QueryVoxel(v.xID, v.yID, v.zID + 1);
if (v4 == null)
{
return(0);
}
Voxel v5 = QueryVoxel(v.xID + 1, v.yID, v.zID + 1);
if (v5 == null)
{
return(0);
}
Voxel v6 = QueryVoxel(v.xID + 1, v.yID + 1, v.zID + 1);
if (v6 == null)
{
return(0);
}
Voxel v7 = QueryVoxel(v.xID, v.yID + 1, v.zID + 1);
if (v7 == null)
{
return(0);
}
int triangleStart = m_triangles.Count;
int createdTriangles = Polygonizer.Process(m_meshingIsolevel,
v0.value,
v1.value,
v2.value,
v3.value,
v4.value,
v5.value,
v6.value,
v7.value,
v0.anchor,
v1.anchor,
v2.anchor,
v3.anchor,
v4.anchor,
v5.anchor,
v6.anchor,
v7.anchor,
ref m_vertices,
ref m_triangles);
// compute per vertex normal
int addedVertCount = 0;
while (m_normals.Count < m_vertices.Count)
{
m_normals.Add(new Vector3(0, 1, 0));
m_uvs.Add(new Vector2(-1, -1));
addedVertCount++;
}
for (int i = triangleStart; i < m_triangles.Count; i += 3)
{
v.trianglesIndicies.Add(i); // add it to each voxel this impacted?
int ia = m_triangles[i];
int ib = m_triangles[i + 1];
int ic = m_triangles[i + 2];
Vector3 a = m_vertices[ia];
Vector3 b = m_vertices[ib];
Vector3 c = m_vertices[ic];
Vector3 n = Vector3.Cross(a - b, b - c).normalized;
m_normals[ia] = n;
m_normals[ib] = n;
m_normals[ic] = n;
CalculateUVs(ia, ib, ic);
}
// adjust per voxel normal
return(createdTriangles);
}