void generate_mesh(DenseGrid3f supportGrid, DenseGridTrilinearImplicit distanceField)
{
DenseGridTrilinearImplicit volume = new DenseGridTrilinearImplicit(
supportGrid, GridOrigin, CellSize);
BoundedImplicitFunction3d inputF = volume;
if (SubtractMesh)
{
BoundedImplicitFunction3d sub = distanceField;
if (SubtractMeshOffset > 0)
{
sub = new ImplicitOffset3d()
{
A = distanceField, Offset = SubtractMeshOffset
}
}
;
ImplicitDifference3d subtract = new ImplicitDifference3d()
{
A = volume, B = sub
};
inputF = subtract;
}
ImplicitHalfSpace3d cutPlane = new ImplicitHalfSpace3d()
{
Origin = Vector3d.Zero, Normal = Vector3d.AxisY
};
ImplicitDifference3d cut = new ImplicitDifference3d()
{
A = inputF, B = cutPlane
};
MarchingCubes mc = new MarchingCubes()
{
Implicit = cut, Bounds = grid_bounds, CubeSize = CellSize
};
mc.Bounds.Min.y = -2 * mc.CubeSize;
mc.Bounds.Min.x -= 2 * mc.CubeSize; mc.Bounds.Min.z -= 2 * mc.CubeSize;
mc.Bounds.Max.x += 2 * mc.CubeSize; mc.Bounds.Max.z += 2 * mc.CubeSize;
mc.Generate();
SupportMesh = mc.Mesh;
}
}
void fill_vertical_spans(DenseGrid3f supportGrid, DenseGridTrilinearImplicit distanceField)
{
int ni = supportGrid.ni, nj = supportGrid.nj, nk = supportGrid.nk;
float dx = (float)CellSize;
Vector3f origin = this.GridOrigin;
// sweep values down, column by column
for (int k = 0; k < nk; ++k)
{
for (int i = 0; i < ni; ++i)
{
bool in_support = false;
for (int j = nj - 1; j >= 0; j--)
{
float fcur = supportGrid[i, j, k];
if (fcur >= 0)
{
Vector3d cell_center = get_cell_center(i, j, k);
if (in_support)
{
bool is_inside = distanceField.Value(ref cell_center) < 0;
if (is_inside)
{
supportGrid[i, j, k] = -3;
in_support = false;
}
else
{
supportGrid[i, j, k] = -1;
}
}
}
else
{
in_support = true;
}
}
}
}
}
void process_version2(DenseGrid3f supportGrid, DenseGridTrilinearImplicit distanceField)
{
int ni = supportGrid.ni, nj = supportGrid.nj, nk = supportGrid.nk;
float dx = (float)CellSize;
Vector3f origin = this.GridOrigin;
// sweep values down layer by layer
DenseGrid2f prev = supportGrid.get_slice(nj - 1, 1);
DenseGrid2f tmp = new DenseGrid2f(prev);
Bitmap3 bmp = new Bitmap3(new Vector3i(ni, nj, nk));
for (int j = nj - 2; j >= 0; j--) {
// skeletonize prev layer
DenseGrid2i prev_skel = binarize(prev, 0.0f);
skeletonize(prev_skel, null, 2);
//dilate_loners(prev_skel, null, 2);
if (j == 0) {
dilate(prev_skel, null, true);
dilate(prev_skel, null, true);
}
for (int k = 1; k < nk - 1; ++k) {
for (int i = 1; i < ni - 1; ++i)
bmp[new Vector3i(i,j,k)] = (prev_skel[i, k] == 1) ? true : false;
}
smooth(prev, tmp, 0.5f, 5);
DenseGrid2f cur = supportGrid.get_slice(j, 1);
cur.set_min(prev);
for (int k = 1; k < nk - 1; ++k) {
for (int i = 1; i < ni - 1; ++i) {
float skelf = prev_skel[i, k] > 0 ? -1.0f : int.MaxValue;
cur[i, k] = Math.Min(cur[i, k], skelf);
if (cur[i, k] < 0) {
Vector3d cell_center = new Vector3f(i * dx, j * dx, k * dx) + origin;
if (distanceField.Value(ref cell_center) < -CellSize)
cur[i, k] = 1;
}
}
}
for (int k = 1; k < nk - 1; ++k) {
for (int i = 1; i < ni - 1; ++i) {
if (is_loner(prev_skel, i, k)) {
foreach (Vector2i d in gIndices.GridOffsets8) {
float f = 1.0f / (float)Math.Sqrt(d.x*d.x + d.y*d.y);
cur[i + d.x, k + d.y] += -0.25f * f;
}
}
}
}
for (int k = 1; k < nk - 1; ++k) {
for (int i = 1; i < ni - 1; ++i) {
supportGrid[i, j, k] = cur[i, k];
}
}
prev.swap(cur);
}
VoxelSurfaceGenerator gen = new VoxelSurfaceGenerator() { Voxels = bmp };
gen.Generate();
Util.WriteDebugMesh(gen.Meshes[0], "c:\\scratch\\binary.obj");
}
void process_version1(DenseGrid3f supportGrid, DenseGridTrilinearImplicit distanceField)
{
int ni = supportGrid.ni, nj = supportGrid.nj, nk = supportGrid.nk;
float dx = (float)CellSize;
Vector3f origin = this.GridOrigin;
// sweep values down, column by column
for (int k = 0; k < nk; ++k) {
for (int i = 0; i < ni; ++i) {
bool in_support = false;
for (int j = nj - 1; j >= 0; j--) {
float fcur = supportGrid[i, j, k];
if (fcur >= 0) {
Vector3d cell_center = new Vector3f(i * dx, j * dx, k * dx) + origin;
if (in_support) {
bool is_inside = distanceField.Value(ref cell_center) < 0;
if (is_inside) {
supportGrid[i, j, k] = -3;
in_support = false;
} else {
supportGrid[i, j, k] = -1;
}
}
} else {
in_support = true;
}
}
}
}
// skeletonize each layer
// todo: would be nice to skeletonize the 3D volume.. ?
DenseGrid3i binary = new DenseGrid3i(ni, nj, nk, 0);
foreach (Vector3i idx in binary.Indices())
binary[idx] = (supportGrid[idx] < 0) ? 1 : 0;
for (int j = 0; j < nj; ++j)
skeletonize_layer(binary, j);
// debug thing
//VoxelSurfaceGenerator voxgen = new VoxelSurfaceGenerator() {
// Voxels = binary.get_bitmap()
//};
//voxgen.Generate();
//Util.WriteDebugMesh(voxgen.makemesh(), "c:\\scratch\\binary.obj");
// for skeleton voxels, we add some power
for (int j = 0; j < nj; ++j) {
for (int k = 1; k < nk - 1; ++k) {
for (int i = 1; i < ni - 1; ++i) {
if (binary[i, j, k] > 0)
supportGrid[i, j, k] = -3;
//else
// supportGrid[i, j, k] = 1; // clear non-skeleton voxels
}
}
}
// power up the ground-plane voxels
for (int k = 0; k < nk; ++k) {
for (int i = 0; i < ni; ++i) {
if (supportGrid[i, 0, k] < 0)
supportGrid[i, 0, k] = -5;
}
}
#if true
DenseGrid3f smoothed = new DenseGrid3f(supportGrid);
float nbr_weight = 0.5f;
for (int iter = 0; iter < 15; ++iter) {
// add some mass to skeleton voxels
for (int j = 0; j < nj; ++j) {
for (int k = 1; k < nk - 1; ++k) {
for (int i = 1; i < ni - 1; ++i) {
if (binary[i, j, k] > 0)
supportGrid[i, j, k] = supportGrid[i, j, k] - nbr_weight / 25.0f;
}
}
}
for (int j = 0; j < nj; ++j) {
for (int k = 1; k < nk - 1; ++k) {
for (int i = 1; i < ni - 1; ++i) {
int neg = 0;
float avg = 0, w = 0;
for (int n = 0; n < 8; ++n) {
int xi = i + gIndices.GridOffsets8[n].x;
int zi = k + gIndices.GridOffsets8[n].y;
float f = supportGrid[xi, j, zi];
if (f < 0) neg++;
avg += nbr_weight * f;
w += nbr_weight;
}
if (neg > -1) {
avg += supportGrid[i, j, k];
w += 1.0f;
smoothed[i, j, k] = avg / w;
} else {
smoothed[i, j, k] = supportGrid[i, j, k];
}
}
}
}
supportGrid.swap(smoothed);
}
#endif
// hard-enforce that skeleton voxels stay inside
//for (int j = 0; j < nj; ++j) {
// for (int k = 1; k < nk - 1; ++k) {
// for (int i = 1; i < ni - 1; ++i) {
// if (binary[i, j, k] > 0)
// supportGrid[i, j, k] = Math.Min(supportGrid[i, j, k], - 1);
// }
// }
//}
}
void generate_support(Vector3f origin, float dx,
int ni, int nj, int nk,
DenseGrid3f supportGrid)
{
supportGrid.resize(ni, nj, nk);
supportGrid.assign(1); // sentinel
if (DebugPrint) System.Console.WriteLine("start");
bool CHECKERBOARD = false;
System.Console.WriteLine("Computing SDF");
// compute unsigned SDF
MeshSignedDistanceGrid sdf = new MeshSignedDistanceGrid(Mesh, CellSize) {
ComputeSigns = true, ExactBandWidth = 3,
/*,ComputeMode = MeshSignedDistanceGrid.ComputeModes.FullGrid*/ };
sdf.CancelF = Cancelled;
sdf.Compute();
if (Cancelled())
return;
var distanceField = new DenseGridTrilinearImplicit(sdf.Grid, sdf.GridOrigin, sdf.CellSize);
double angle = MathUtil.Clamp(OverhangAngleDeg, 0.01, 89.99);
double cos_thresh = Math.Cos(angle * MathUtil.Deg2Rad);
System.Console.WriteLine("Marking overhangs");
// Compute narrow-band distances. For each triangle, we find its grid-coord-bbox,
// and compute exact distances within that box. The intersection_count grid
// is also filled in this computation
double ddx = (double)dx;
double ox = (double)origin[0], oy = (double)origin[1], oz = (double)origin[2];
Vector3d va = Vector3d.Zero, vb = Vector3d.Zero, vc = Vector3d.Zero;
foreach (int tid in Mesh.TriangleIndices()) {
if (tid % 100 == 0 && Cancelled())
break;
Mesh.GetTriVertices(tid, ref va, ref vb, ref vc);
Vector3d normal = MathUtil.Normal(ref va, ref vb, ref vc);
if (normal.Dot(-Vector3d.AxisY) < cos_thresh)
continue;
// real ijk coordinates of va/vb/vc
double fip = (va[0] - ox) / ddx, fjp = (va[1] - oy) / ddx, fkp = (va[2] - oz) / ddx;
double fiq = (vb[0] - ox) / ddx, fjq = (vb[1] - oy) / ddx, fkq = (vb[2] - oz) / ddx;
double fir = (vc[0] - ox) / ddx, fjr = (vc[1] - oy) / ddx, fkr = (vc[2] - oz) / ddx;
// clamped integer bounding box of triangle plus exact-band
int exact_band = 0;
int i0 = MathUtil.Clamp(((int)MathUtil.Min(fip, fiq, fir)) - exact_band, 0, ni - 1);
int i1 = MathUtil.Clamp(((int)MathUtil.Max(fip, fiq, fir)) + exact_band + 1, 0, ni - 1);
int j0 = MathUtil.Clamp(((int)MathUtil.Min(fjp, fjq, fjr)) - exact_band, 0, nj - 1);
int j1 = MathUtil.Clamp(((int)MathUtil.Max(fjp, fjq, fjr)) + exact_band + 1, 0, nj - 1);
int k0 = MathUtil.Clamp(((int)MathUtil.Min(fkp, fkq, fkr)) - exact_band, 0, nk - 1);
int k1 = MathUtil.Clamp(((int)MathUtil.Max(fkp, fkq, fkr)) + exact_band + 1, 0, nk - 1);
// don't put into y=0 plane
if (j0 == 0)
j0 = 1;
// compute distance for each tri inside this bounding box
// note: this can be very conservative if the triangle is large and on diagonal to grid axes
for (int k = k0; k <= k1; ++k) {
for (int j = j0; j <= j1; ++j) {
for (int i = i0; i <= i1; ++i) {
Vector3d gx = new Vector3d((float)i * dx + origin[0], (float)j * dx + origin[1], (float)k * dx + origin[2]);
float d = (float)MeshSignedDistanceGrid.point_triangle_distance(ref gx, ref va, ref vb, ref vc);
// vertical checkerboard pattern (eg 'tips')
if (CHECKERBOARD) {
int zz = (k % 2 == 0) ? 1 : 0;
if (i % 2 == zz)
continue;
}
if (d < dx / 2) {
if (j > 1) {
supportGrid[i, j, k] = SUPPORT_TIP_TOP;
supportGrid[i, j - 1, k] = SUPPORT_TIP_BASE;
} else {
supportGrid[i, j, k] = SUPPORT_TIP_BASE;
}
}
}
}
}
}
if (Cancelled())
return;
//process_version1(supportGrid, distanceField);
//process_version2(supportGrid, distanceField);
generate_graph(supportGrid, distanceField);
//Util.WriteDebugMesh(MakeDebugGraphMesh(), "c:\\scratch\\__LAST_GRAPH_INIT.obj");
postprocess_graph();
//Util.WriteDebugMesh(MakeDebugGraphMesh(), "c:\\scratch\\__LAST_GRAPH_OPT.obj");
}
void generate_graph(DenseGrid3f supportGrid, DenseGridTrilinearImplicit distanceField)
{
int ni = supportGrid.ni, nj = supportGrid.nj, nk = supportGrid.nk;
float dx = (float)CellSize;
Vector3f origin = this.GridOrigin;
// parameters for initializing cost grid
float MODEL_SPACE = 0.01f; // needs small positive so that points on triangles count as inside (eg on ground plane)
//float MODEL_SPACE = 2.0f*(float)CellSize;
float CRAZY_DISTANCE = 99999.0f;
bool UNIFORM_DISTANCE = true;
float MAX_DIST = 10 * (float)CellSize;
// parameters for sorting seeds
Vector3i center_idx = new Vector3i(ni / 2, 0, nk / 2); // middle
//Vector3i center_idx = new Vector3i(0, 0, 0); // corner
bool reverse_per_layer = true;
DenseGrid3f costGrid = new DenseGrid3f(supportGrid);
foreach ( Vector3i ijk in costGrid.Indices() ) {
Vector3d cell_center = new Vector3f(ijk.x * dx, ijk.y * dx, ijk.z * dx) + origin;
float f = (float)distanceField.Value(ref cell_center);
if (f <= MODEL_SPACE)
f = CRAZY_DISTANCE;
else if (UNIFORM_DISTANCE)
f = 1.0f;
else if (f > MAX_DIST)
f = MAX_DIST;
costGrid[ijk] = f;
}
// Find seeds on each layer, sort, and add to accumulated bottom-up seeds list.
// This sorting has an *enormous* effect on the support generation.
List<Vector3i> seeds = new List<Vector3i>();
List<Vector3i> layer_seeds = new List<Vector3i>();
for (int j = 0; j < nj; ++j) {
layer_seeds.Clear();
for (int k = 0; k < nk; ++k) {
for (int i = 0; i < ni; ++i) {
if (supportGrid[i, j, k] == SUPPORT_TIP_BASE)
layer_seeds.Add(new Vector3i(i, j, k));
}
}
layer_seeds.Sort((a, b) => {
Vector3i pa = a; pa.y = 0;
Vector3i pb = b; pb.y = 0;
int sa = (pa-center_idx).LengthSquared, sb = (pb-center_idx).LengthSquared;
return sa.CompareTo(sb);
});
// reversing sort order is intresting?
if(reverse_per_layer)
layer_seeds.Reverse();
seeds.AddRange(layer_seeds);
}
HashSet<Vector3i> seed_indices = new HashSet<Vector3i>(seeds);
// gives very different results...
if (ProcessBottomUp == false)
seeds.Reverse();
// for linear index a, is this a node we allow in graph? (ie graph bounds)
Func<int, bool> node_filter_f = (a) => {
Vector3i ai = costGrid.to_index(a);
// why not y check??
return ai.x > 0 && ai.z > 0 && ai.x != ni - 1 && ai.y != nj - 1 && ai.z != nk - 1;
};
// distance from linear index a to linear index b
// this defines the cost field we want to find shortest path through
Func<int, int, float> node_dist_f = (a, b) => {
Vector3i ai = costGrid.to_index(a), bi = costGrid.to_index(b);
if (bi.y >= ai.y) // b.y should always be a.y-1
return float.MaxValue;
float sg = supportGrid[bi];
// don't connect to tips
//if (sg == SUPPORT_TIP_BASE || sg == SUPPORT_TIP_TOP)
// return float.MaxValue;
if (sg == SUPPORT_TIP_TOP)
return float.MaxValue;
if (sg < 0)
return -999999; // if b is already used, we will terminate there, so this is a good choice
// otherwise cost is sqr-grid-distance + costGrid value (which is basically distance to surface)
float c = costGrid[b];
float f = (float)(Math.Sqrt((bi - ai).LengthSquared) * CellSize);
//float f = 0;
return c + f;
};
// which linear-index nbrs to consider for linear index a
Func<int, IEnumerable<int>> neighbour_f = (a) => {
Vector3i ai = costGrid.to_index(a);
return down_neighbours(ai, costGrid);
};
// when do we terminate
Func<int, bool> terminate_f = (a) => {
Vector3i ai = costGrid.to_index(a);
// terminate if we hit existing support path
if (seed_indices.Contains(ai) == false && supportGrid[ai] < 0)
return true;
// terminate if we hit ground plane
if (ai.y == 0)
return true;
return false;
};
DijkstraGraphDistance dijkstra = new DijkstraGraphDistance(ni * nj * nk, false,
node_filter_f, node_dist_f, neighbour_f);
dijkstra.TrackOrder = true;
List<int> path = new List<int>();
Graph = new DGraph3();
Dictionary<Vector3i, int> CellToGraph = new Dictionary<Vector3i, int>();
TipVertices = new HashSet<int>();
TipBaseVertices = new HashSet<int>();
GroundVertices = new HashSet<int>();
// seeds are tip-base points
for (int k = 0; k < seeds.Count; ++k) {
// add seed point (which is a tip-base vertex) as seed for dijkstra prop
int seed = costGrid.to_linear(seeds[k]);
dijkstra.Reset();
dijkstra.AddSeed(seed, 0);
// compute to termination (ground, existing node, etc)
int base_node = dijkstra.ComputeToNode(terminate_f);
if (base_node < 0)
base_node = dijkstra.GetOrder().Last();
// extract the path
path.Clear();
dijkstra.GetPathToSeed(base_node, path);
int N = path.Count;
// first point on path is termination point.
// create vertex for it if we have not yet
Vector3i basept_idx = supportGrid.to_index(path[0]);
int basept_vid;
if ( CellToGraph.TryGetValue(basept_idx, out basept_vid) == false ) {
Vector3d curv = get_cell_center(basept_idx);
if (basept_idx.y == 0) {
curv.y = 0;
}
basept_vid = Graph.AppendVertex(curv);
if (basept_idx.y == 0) {
GroundVertices.Add(basept_vid);
}
CellToGraph[basept_idx] = basept_vid;
}
int cur_vid = basept_vid;
// now walk up path and create vertices as necessary
for (int i = 0; i < N; ++i) {
int idx = path[i];
if ( supportGrid[idx] >= 0 )
supportGrid[idx] = SUPPORT_GRID_USED;
if ( i > 0 ) {
Vector3i next_idx = supportGrid.to_index(path[i]);
int next_vid;
if (CellToGraph.TryGetValue(next_idx, out next_vid) == false) {
Vector3d nextv = get_cell_center(next_idx);
next_vid = Graph.AppendVertex(nextv);
CellToGraph[next_idx] = next_vid;
}
Graph.AppendEdge(cur_vid, next_vid);
cur_vid = next_vid;
}
}
// seed was tip-base so we should always get back there. Then we
// explicitly add tip-top and edge to it.
if ( supportGrid[path[N-1]] == SUPPORT_TIP_BASE ) {
Vector3i vec_idx = supportGrid.to_index(path[N-1]);
TipBaseVertices.Add(CellToGraph[vec_idx]);
Vector3i tip_idx = vec_idx + Vector3i.AxisY;
int tip_vid;
if (CellToGraph.TryGetValue(tip_idx, out tip_vid) == false) {
Vector3d tipv = get_cell_center(tip_idx);
tip_vid = Graph.AppendVertex(tipv);
CellToGraph[tip_idx] = tip_vid;
Graph.AppendEdge(cur_vid, tip_vid);
TipVertices.Add(tip_vid);
}
}
}
/*
* Snap tips to surface
*/
gParallel.ForEach(TipVertices, (tip_vid) => {
bool snapped = false;
Vector3d v = Graph.GetVertex(tip_vid);
Frame3f hitF;
// try shooting ray straight up. if that hits, and point is close, we use it
if (MeshQueries.RayHitPointFrame(Mesh, MeshSpatial, new Ray3d(v, Vector3d.AxisY), out hitF)) {
if (v.Distance(hitF.Origin) < 2 * CellSize) {
v = hitF.Origin;
snapped = true;
}
}
// if that failed, try straight down
if (!snapped) {
if (MeshQueries.RayHitPointFrame(Mesh, MeshSpatial, new Ray3d(v, -Vector3d.AxisY), out hitF)) {
if (v.Distance(hitF.Origin) < CellSize) {
v = hitF.Origin;
snapped = true;
}
}
}
// if it missed, or hit pt was too far, find nearest point and try that
if (!snapped) {
hitF = MeshQueries.NearestPointFrame(Mesh, MeshSpatial, v);
if (v.Distance(hitF.Origin) < 2 * CellSize) {
v = hitF.Origin;
snapped = true;
}
// can this ever fail? tips should always be within 2 cells...
}
if (snapped)
Graph.SetVertex(tip_vid, v);
});
}
void generate_support(Vector3f origin, float dx,
int ni, int nj, int nk,
DenseGrid3f supportGrid)
{
supportGrid.resize(ni, nj, nk);
supportGrid.assign(1); // sentinel
bool CHECKERBOARD = false;
// compute unsigned SDF
int exact_band = 1;
if (SubtractMesh && SubtractMeshOffset > 0)
{
int offset_band = (int)(SubtractMeshOffset / CellSize) + 1;
exact_band = Math.Max(exact_band, offset_band);
}
sdf = new MeshSignedDistanceGrid(Mesh, CellSize)
{
ComputeSigns = true, ExactBandWidth = exact_band
};
sdf.CancelF = this.CancelF;
sdf.Compute();
if (CancelF())
{
return;
}
var distanceField = new DenseGridTrilinearImplicit(sdf.Grid, sdf.GridOrigin, sdf.CellSize);
double angle = MathUtil.Clamp(OverhangAngleDeg, 0.01, 89.99);
double cos_thresh = Math.Cos(angle * MathUtil.Deg2Rad);
// Compute narrow-band distances. For each triangle, we find its grid-coord-bbox,
// and compute exact distances within that box. The intersection_count grid
// is also filled in this computation
double ddx = (double)dx;
double ox = (double)origin[0], oy = (double)origin[1], oz = (double)origin[2];
Vector3d va = Vector3d.Zero, vb = Vector3d.Zero, vc = Vector3d.Zero;
foreach (int tid in Mesh.TriangleIndices())
{
if (tid % 100 == 0 && CancelF())
{
break;
}
Mesh.GetTriVertices(tid, ref va, ref vb, ref vc);
Vector3d normal = MathUtil.Normal(ref va, ref vb, ref vc);
if (normal.Dot(-Vector3d.AxisY) < cos_thresh)
{
continue;
}
// real ijk coordinates of va/vb/vc
double fip = (va[0] - ox) / ddx, fjp = (va[1] - oy) / ddx, fkp = (va[2] - oz) / ddx;
double fiq = (vb[0] - ox) / ddx, fjq = (vb[1] - oy) / ddx, fkq = (vb[2] - oz) / ddx;
double fir = (vc[0] - ox) / ddx, fjr = (vc[1] - oy) / ddx, fkr = (vc[2] - oz) / ddx;
// clamped integer bounding box of triangle plus exact-band
int extra_band = 0;
int i0 = MathUtil.Clamp(((int)MathUtil.Min(fip, fiq, fir)) - extra_band, 0, ni - 1);
int i1 = MathUtil.Clamp(((int)MathUtil.Max(fip, fiq, fir)) + extra_band + 1, 0, ni - 1);
int j0 = MathUtil.Clamp(((int)MathUtil.Min(fjp, fjq, fjr)) - extra_band, 0, nj - 1);
int j1 = MathUtil.Clamp(((int)MathUtil.Max(fjp, fjq, fjr)) + extra_band + 1, 0, nj - 1);
int k0 = MathUtil.Clamp(((int)MathUtil.Min(fkp, fkq, fkr)) - extra_band, 0, nk - 1);
int k1 = MathUtil.Clamp(((int)MathUtil.Max(fkp, fkq, fkr)) + extra_band + 1, 0, nk - 1);
// don't put into y=0 plane
//if (j0 == 0)
// j0 = 1;
// compute distance for each tri inside this bounding box
// note: this can be very conservative if the triangle is large and on diagonal to grid axes
for (int k = k0; k <= k1; ++k)
{
for (int j = j0; j <= j1; ++j)
{
for (int i = i0; i <= i1; ++i)
{
Vector3d gx = new Vector3d((float)i * dx + origin[0], (float)j * dx + origin[1], (float)k * dx + origin[2]);
float d = (float)MeshSignedDistanceGrid.point_triangle_distance(ref gx, ref va, ref vb, ref vc);
// vertical checkerboard pattern (eg 'tips')
if (CHECKERBOARD)
{
int zz = (k % 2 == 0) ? 1 : 0;
if (i % 2 == zz)
{
continue;
}
}
if (d < dx / 2)
{
supportGrid[i, j, k] = SUPPORT_TIP_TOP;
}
}
}
}
}
if (CancelF())
{
return;
}
fill_vertical_spans(supportGrid, distanceField);
generate_mesh(supportGrid, distanceField);
}
