/// <summary>
/// foreach edge [vid,b] connected to junction vertex vid, remove, add new vertex c,
/// and then add new edge [b,c]. Optionally move c a bit back along edge from vid.
/// </summary>
public static void DisconnectJunction(DGraph3 graph, int vid, double shrinkFactor = 1.0)
{
Vector3d v = graph.GetVertex(vid);
int[] nbr_verts = graph.VtxVerticesItr(vid).ToArray();
for (int k = 0; k < nbr_verts.Length; ++k)
{
int eid = graph.FindEdge(vid, nbr_verts[k]);
graph.RemoveEdge(eid, true);
if (graph.IsVertex(nbr_verts[k]))
{
Vector3d newpos = Vector3d.Lerp(graph.GetVertex(nbr_verts[k]), v, shrinkFactor);
int newv = graph.AppendVertex(newpos);
graph.AppendEdge(nbr_verts[k], newv);
}
}
}
protected void compute_full(IEnumerable <int> Triangles, bool bIsFullMeshHint = false)
{
Graph = new DGraph3();
if (WantGraphEdgeInfo)
{
GraphEdges = new DVector <GraphEdgeInfo>();
}
Vertices = new Dictionary <Vector3d, int>();
// multithreaded precomputation of per-vertex values
double[] vertex_values = null;
if (PrecomputeVertexValues)
{
vertex_values = new double[Mesh.MaxVertexID];
IEnumerable <int> verts = Mesh.VertexIndices();
if (bIsFullMeshHint == false)
{
MeshVertexSelection vertices = new MeshVertexSelection(Mesh);
vertices.SelectTriangleVertices(Triangles);
verts = vertices;
}
gParallel.ForEach(verts, (vid) => {
vertex_values[vid] = ValueF(Mesh.GetVertex(vid));
});
VertexValueF = (vid) => { return(vertex_values[vid]); };
}
foreach (int tid in Triangles)
{
Vector3dTuple3 tv = new Vector3dTuple3();
Mesh.GetTriVertices(tid, ref tv.V0, ref tv.V1, ref tv.V2);
Index3i triVerts = Mesh.GetTriangle(tid);
Vector3d f = (VertexValueF != null) ?
new Vector3d(VertexValueF(triVerts.a), VertexValueF(triVerts.b), VertexValueF(triVerts.c))
: new Vector3d(ValueF(tv.V0), ValueF(tv.V1), ValueF(tv.V2));
// round f to 0 within epsilon?
if (f.x < 0 && f.y < 0 && f.z < 0)
{
continue;
}
if (f.x > 0 && f.y > 0 && f.z > 0)
{
continue;
}
Index3i triEdges = Mesh.GetTriEdges(tid);
if (f.x * f.y * f.z == 0)
{
int z0 = (f.x == 0) ? 0 : ((f.y == 0) ? 1 : 2);
int i1 = (z0 + 1) % 3, i2 = (z0 + 2) % 3;
if (f[i1] * f[i2] > 0)
{
continue; // single-vertex-crossing case, skip here and let other edges catch it
}
if (f[i1] == 0 || f[i2] == 0)
{
// on-edge case
int z1 = f[i1] == 0 ? i1 : i2;
if ((z0 + 1) % 3 != z1)
{
int tmp = z0; z0 = z1; z1 = tmp; // catch reverse-orientation cases
}
int e0 = add_or_append_vertex(Mesh.GetVertex(triVerts[z0]));
int e1 = add_or_append_vertex(Mesh.GetVertex(triVerts[z1]));
int graph_eid = Graph.AppendEdge(e0, e1, (int)TriangleCase.OnEdge);
if (graph_eid >= 0 && WantGraphEdgeInfo)
{
add_on_edge(graph_eid, tid, triEdges[z0], new Index2i(e0, e1));
}
}
else
{
// edge/vertex case
Util.gDevAssert(f[i1] * f[i2] < 0);
int vert_vid = add_or_append_vertex(Mesh.GetVertex(triVerts[z0]));
int i = i1, j = i2;
if (triVerts[j] < triVerts[i])
{
int tmp = i; i = j; j = tmp;
}
Vector3d cross = find_crossing(tv[i], tv[j], f[i], f[j]);
int cross_vid = add_or_append_vertex(cross);
add_edge_pos(triVerts[i], triVerts[j], cross);
int graph_eid = Graph.AppendEdge(vert_vid, cross_vid, (int)TriangleCase.EdgeVertex);
if (graph_eid >= 0 && WantGraphEdgeInfo)
{
add_edge_vert(graph_eid, tid, triEdges[(z0 + 1) % 3], triVerts[z0], new Index2i(vert_vid, cross_vid));
}
}
}
else
{
Index3i cross_verts = Index3i.Min;
int less_than = 0;
for (int tei = 0; tei < 3; ++tei)
{
int i = tei, j = (tei + 1) % 3;
if (f[i] < 0)
{
less_than++;
}
if (f[i] * f[j] > 0)
{
continue;
}
if (triVerts[j] < triVerts[i])
{
int tmp = i; i = j; j = tmp;
}
Vector3d cross = find_crossing(tv[i], tv[j], f[i], f[j]);
cross_verts[tei] = add_or_append_vertex(cross);
add_edge_pos(triVerts[i], triVerts[j], cross);
}
int e0 = (cross_verts.a == int.MinValue) ? 1 : 0;
int e1 = (cross_verts.c == int.MinValue) ? 1 : 2;
if (e0 == 0 && e1 == 2) // preserve orientation order
{
e0 = 2; e1 = 0;
}
// preserving orientation does not mean we get a *consistent* orientation across faces.
// To do that, we need to assign "sides". Either we have 1 less-than-0 or 1 greater-than-0 vtx.
// Arbitrary decide that we want loops oriented like bdry loops would be if we discarded less-than side.
// In that case, when we are "cutting off" one vertex, orientation would end up flipped
if (less_than == 1)
{
int tmp = e0; e0 = e1; e1 = tmp;
}
int ev0 = cross_verts[e0];
int ev1 = cross_verts[e1];
// [RMS] if function is garbage, we can end up w/ case where both crossings
// happen at same vertex, even though values are not the same (eg if
// some values are double.MaxValue). We will just fail in these cases.
if (ev0 != ev1)
{
Util.gDevAssert(ev0 != int.MinValue && ev1 != int.MinValue);
int graph_eid = Graph.AppendEdge(ev0, ev1, (int)TriangleCase.EdgeEdge);
if (graph_eid >= 0 && WantGraphEdgeInfo)
{
add_edge_edge(graph_eid, tid, new Index2i(triEdges[e0], triEdges[e1]), new Index2i(ev0, ev1));
}
}
}
}
Vertices = null;
}
protected void compute_full(IEnumerable <int> Triangles)
{
Graph = new DGraph3();
if (WantGraphEdgeInfo)
{
GraphEdges = new DVector <GraphEdgeInfo>();
}
Vertices = new Dictionary <Vector3d, int>();
foreach (int tid in Triangles)
{
Vector3dTuple3 tv = new Vector3dTuple3();
Mesh.GetTriVertices(tid, ref tv.V0, ref tv.V1, ref tv.V2);
Vector3d f = new Vector3d(ValueF(tv.V0), ValueF(tv.V1), ValueF(tv.V2));
// round f to 0 within epsilon?
if (f.x < 0 && f.y < 0 && f.z < 0)
{
continue;
}
if (f.x > 0 && f.y > 0 && f.z > 0)
{
continue;
}
Index3i triVerts = Mesh.GetTriangle(tid);
Index3i triEdges = Mesh.GetTriEdges(tid);
if (f.x * f.y * f.z == 0)
{
int z0 = (f.x == 0) ? 0 : ((f.y == 0) ? 1 : 2);
int i1 = (z0 + 1) % 3, i2 = (z0 + 2) % 3;
if (f[i1] * f[i2] > 0)
{
continue; // single-vertex-crossing case, skip here and let other edges catch it
}
if (f[i1] == 0 || f[i2] == 0)
{
// on-edge case
int z1 = f[i1] == 0 ? i1 : i2;
int e0 = add_or_append_vertex(Mesh.GetVertex(triVerts[z0]));
int e1 = add_or_append_vertex(Mesh.GetVertex(triVerts[z1]));
int graph_eid = Graph.AppendEdge(e0, e1, (int)TriangleCase.OnEdge);
if (WantGraphEdgeInfo)
{
add_on_edge(graph_eid, tid, triEdges[z0]);
}
}
else
{
// edge/vertex case
Util.gDevAssert(f[i1] * f[i2] < 0);
int vert_vid = add_or_append_vertex(Mesh.GetVertex(triVerts[z0]));
int i = i1, j = i2;
if (triVerts[j] < triVerts[i])
{
int tmp = i; i = j; j = tmp;
}
Vector3d cross = find_crossing(tv[i], tv[j], f[i], f[j]);
int cross_vid = add_or_append_vertex(cross);
int graph_eid = Graph.AppendEdge(vert_vid, cross_vid, (int)TriangleCase.EdgeVertex);
if (WantGraphEdgeInfo)
{
add_edge_edge(graph_eid, tid, new Index2i(triEdges[(z0 + 1) % 3], triVerts[z0]));
}
}
}
else
{
Index3i cross_verts = Index3i.Min;
for (int ti = 0; ti < 3; ++ti)
{
int i = ti, j = (ti + 1) % 3;
if (f[i] * f[j] > 0)
{
continue;
}
if (triVerts[j] < triVerts[i])
{
int tmp = i; i = j; j = tmp;
}
Vector3d cross = find_crossing(tv[i], tv[j], f[i], f[j]);
cross_verts[ti] = add_or_append_vertex(cross);
}
int e0 = (cross_verts.a == int.MinValue) ? 1 : 0;
int e1 = (cross_verts.c == int.MinValue) ? 1 : 2;
int ev0 = cross_verts[e0];
int ev1 = cross_verts[e1];
Util.gDevAssert(ev0 != int.MinValue && ev1 != int.MinValue);
int graph_eid = Graph.AppendEdge(ev0, ev1, (int)TriangleCase.EdgeEdge);
if (WantGraphEdgeInfo)
{
add_edge_edge(graph_eid, tid, new Index2i(triEdges[e0], triEdges[e1]));
}
}
}
Vertices = null;
}
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);
});
}