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; } }
public static void test_marching_cubes_implicits() { DMesh3 mesh = TestUtil.LoadTestInputMesh("bunny_solid.obj"); MeshTransforms.Translate(mesh, -mesh.CachedBounds.Center); double meshCellsize = mesh.CachedBounds.MaxDim / 32; MeshSignedDistanceGrid levelSet = new MeshSignedDistanceGrid(mesh, meshCellsize); levelSet.ExactBandWidth = 3; levelSet.UseParallel = true; levelSet.ComputeMode = MeshSignedDistanceGrid.ComputeModes.NarrowBandOnly; levelSet.Compute(); var meshIso = new DenseGridTrilinearImplicit(levelSet.Grid, levelSet.GridOrigin, levelSet.CellSize); ImplicitOffset3d offsetMeshIso = new ImplicitOffset3d() { A = meshIso, Offset = 2.0 }; double r = 15.0; ImplicitSphere3d sphere1 = new ImplicitSphere3d() { Origin = Vector3d.Zero, Radius = r }; ImplicitSphere3d sphere2 = new ImplicitSphere3d() { Origin = r * Vector3d.AxisX, Radius = r }; ImplicitAxisAlignedBox3d aabox1 = new ImplicitAxisAlignedBox3d() { AABox = new AxisAlignedBox3d(r * 0.5 * Vector3d.One, r, r * 0.75, r * 0.5) }; ImplicitBox3d box1 = new ImplicitBox3d() { Box = new Box3d(new Frame3f(r * 0.5 * Vector3d.One, Vector3d.One.Normalized), new Vector3d(r, r * 0.75, r * 0.5)) }; ImplicitLine3d line1 = new ImplicitLine3d() { Segment = new Segment3d(Vector3d.Zero, r * Vector3d.One), Radius = 3.0 }; ImplicitHalfSpace3d half1 = new ImplicitHalfSpace3d() { Origin = Vector3d.Zero, Normal = Vector3d.One.Normalized }; ImplicitUnion3d union = new ImplicitUnion3d() { A = sphere1, B = line1 }; ImplicitDifference3d difference = new ImplicitDifference3d() { A = meshIso, B = aabox1 }; ImplicitIntersection3d intersect = new ImplicitIntersection3d() { A = meshIso, B = half1 }; ImplicitNaryUnion3d nunion = new ImplicitNaryUnion3d() { Children = new List <BoundedImplicitFunction3d>() { offsetMeshIso, sphere1, sphere2 } }; ImplicitNaryDifference3d ndifference = new ImplicitNaryDifference3d() { A = offsetMeshIso, BSet = new List <BoundedImplicitFunction3d>() { sphere1, sphere2 } }; ImplicitBlend3d blend = new ImplicitBlend3d() { A = sphere1, B = sphere2 }; BoundedImplicitFunction3d root = intersect; AxisAlignedBox3d bounds = root.Bounds(); int numcells = 64; MarchingCubes c = new MarchingCubes(); c.RootMode = MarchingCubes.RootfindingModes.LerpSteps; c.RootModeSteps = 5; c.Implicit = root; c.Bounds = bounds; c.CubeSize = bounds.MaxDim / numcells; c.Bounds.Expand(3 * c.CubeSize); c.Generate(); MeshNormals.QuickCompute(c.Mesh); TestUtil.WriteTestOutputMesh(c.Mesh, "marching_cubes_implicit.obj"); }
public virtual void Generate() { AxisAlignedBox3d graphBox = Graph.CachedBounds; graphBox.Expand(2 * PostRadius); double cellSize = (SamplerCellSizeHint == 0) ? (PostRadius / 5) : SamplerCellSizeHint; ImplicitFieldSampler3d sampler = new ImplicitFieldSampler3d(graphBox, cellSize); ActualCellSize = cellSize; // sample segments into graph ImplicitLine3d line = new ImplicitLine3d() { Radius = PostRadius }; foreach (int eid in Graph.EdgeIndices()) { Index2i ev = Graph.GetEdgeV(eid); Vector3d v0 = Graph.GetVertex(ev.a); Vector3d v1 = Graph.GetVertex(ev.b); double r = PostRadius; int upper_vid = (v0.y > v1.y) ? ev.a : ev.b; if (TipVertices.Contains(upper_vid)) { r = TipRadius; } line.Segment = new Segment3d(v0, v1); line.Radius = r; sampler.Sample(line, line.Radius / 2); } foreach (int vid in GroundVertices) { Vector3d v = Graph.GetVertex(vid); sampler.Sample(new ImplicitSphere3d() { Origin = v - (PostRadius / 2) * Vector3d.AxisY, Radius = GroundRadius }); } ImplicitHalfSpace3d cutPlane = new ImplicitHalfSpace3d() { Origin = Vector3d.Zero, Normal = Vector3d.AxisY }; ImplicitDifference3d cut = new ImplicitDifference3d() { A = sampler.ToImplicit(), B = cutPlane }; MarchingCubes mc = new MarchingCubes() { Implicit = cut, Bounds = graphBox, CubeSize = PostRadius / 3 }; 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.CancelF = this.Cancelled; mc.Generate(); ResultMesh = mc.Mesh; }