public VoxelGrid(Component component, Vect3 plane1Normal = null, Vect3 plane2Normal = null, Vect3 plane3Normal = null)
{
orientedBbox = new OrientedBBox(component, plane1Normal, plane2Normal, plane3Normal);
componentOBBs[component.index] = orientedBbox;
SetupVoxelGrid();
this.CreateShellFromFaces(component);
}
public VoxelGrid(Structure structure, Vect3 plane1Normal = null, Vect3 plane2Normal = null, Vect3 plane3Normal = null)
{
orientedBbox = new OrientedBBox(structure, plane1Normal, plane2Normal, plane3Normal);
SetupVoxelGrid(structure);
foreach (Component component in structure.components)
{
CreateShellFromFaces(component);
}
}
/*
* Fills internal volume of voxels by finding points in the voxel grid captured
* by a mesh. Relies on the original meshes to perform odd/even polygon capture calculation.
*
* https://en.wikipedia.org/wiki/Point_in_polygon
*/
public void FillInternalVolume(Component component)
{
OrientedBBox componentOBB = componentOBBs[component.index];
List <Vect3> points = new List <Vect3>();
foreach (var vertex in component.vertices)
{
points.Add(vertex.coordinate);
}
VoxelSpan componentVoxelSpan = new VoxelSpan(points, this, BorderOffset);
for (int x = componentVoxelSpan.minX; x < componentVoxelSpan.maxX; x++)
{
for (int z = componentVoxelSpan.minZ; z < componentVoxelSpan.maxZ; z++)
{
for (int y = componentVoxelSpan.minY; y < componentVoxelSpan.maxY; y++)
{
if (!coordinateGrid[x][y][z] && coordinateGrid[x][Math.Max(0, y - 1)][z])
{
Vect3 globalPos = voxelStartCoordinate +
orientedBbox.localX * x * resolution +
orientedBbox.localY * y * resolution +
orientedBbox.localZ * z * resolution;
if (!componentOBB.ContainsGlobalCoordinate(globalPos, OrientedBBoxExpansionFactor))
{
continue;
}
int intersects = 0;
foreach (Face face in component.faces)
{
Vect3 triA = component.GetCoordinate(face.vertexIndices[0]);
Vect3 triB = component.GetCoordinate(face.vertexIndices[1]);
Vect3 triC = component.GetCoordinate(face.vertexIndices[2]);
// if (intersect_triangle(globalPos, Vect3.Up, triA, triB, triC))
if (rayIntersectsTriangle(globalPos, Vect3.Up, triA, triB, triC))
{
intersects++;
}
}
if ((intersects % 2) != 0)
{
int rise = 0;
while (!coordinateGrid[x][y + rise][z])
{
coordinateGrid[x][y + rise][z] = true;
rise++;
}
}
else if (intersects == 0)
{
// If there is no intersecting surface above whatsoever, this column cannot
// contain points that are inside a polygon.
break;
}
}
}
}
}
}
private void SetupVoxelGrid(Structure structure = null)
{
ComponentWiseResolutionDivider = DefaultComponentWiseResolutionDivider;
double rightLength;
double heightLength;
double depthLength;
if (resolution == 0)
{
if (structure != null)
{
double shortestSide = 0;
foreach (var component in structure.components)
{
OrientedBBox componentOBB = new OrientedBBox(component);
rightLength = (componentOBB.localMaxX - componentOBB.localOrigin).Length();
heightLength = (componentOBB.localMaxY - componentOBB.localOrigin).Length();
depthLength = (componentOBB.localMaxZ - componentOBB.localOrigin).Length();
shortestSide += Math.Min(rightLength, Math.Min(heightLength, depthLength));
componentOBBs[component.index] = componentOBB;
}
shortestSide /= structure.components.Count;
resolution = shortestSide / ComponentWiseResolutionDivider;
}
else
{
rightLength = (orientedBbox.localMaxX - orientedBbox.localOrigin).Length();
heightLength = (orientedBbox.localMaxY - orientedBbox.localOrigin).Length();
depthLength = (orientedBbox.localMaxZ - orientedBbox.localOrigin).Length();
double shortestSide = Math.Min(rightLength, Math.Min(heightLength, depthLength));
resolution = shortestSide / ComponentWiseResolutionDivider;
}
}
halfResolution = resolution / 2d;
rightLength = (orientedBbox.localMaxX - orientedBbox.localOrigin).Length();
heightLength = (orientedBbox.localMaxY - orientedBbox.localOrigin).Length();
depthLength = (orientedBbox.localMaxZ - orientedBbox.localOrigin).Length();
xBound = Convert.ToInt32(Math.Round(rightLength / resolution)) + 4 + 1;
yBound = Convert.ToInt32(Math.Round(heightLength / resolution)) + 4 + 1;
zBound = Convert.ToInt32(Math.Round(depthLength / resolution)) + 4 + 1;
voxelStartCoordinate = orientedBbox.localOrigin - (orientedBbox.localX * 2d * resolution +
orientedBbox.localY * 2d * resolution +
orientedBbox.localZ * 2d * resolution);
// Include offset to move start position to the first cube center.
voxelMiddleStartCoordinate = orientedBbox.localOrigin - (orientedBbox.localX * 1.5d * resolution +
orientedBbox.localY * 1.5d * resolution +
orientedBbox.localZ * 1.5d * resolution);
coordinateGrid = new bool[xBound][][];
for (int i = 0; i < coordinateGrid.Length; i++)
{
coordinateGrid[i] = new bool[yBound][];
for (int j = 0; j < coordinateGrid[i].Length; j++)
{
coordinateGrid[i][j] = new bool[zBound];
}
}
// Resolution offsets are based around the Voxel center. This allows faster intersection calculations.
resolutionOffsets = new List <Vect3>
{
new Vect3(-halfResolution, -halfResolution, -halfResolution),
new Vect3(-halfResolution, -halfResolution, halfResolution),
new Vect3(-halfResolution, halfResolution, -halfResolution),
new Vect3(-halfResolution, halfResolution, halfResolution),
new Vect3(halfResolution, -halfResolution, -halfResolution),
new Vect3(halfResolution, -halfResolution, halfResolution),
new Vect3(halfResolution, halfResolution, -halfResolution),
new Vect3(halfResolution, halfResolution, halfResolution)
};
}
