public MarchingCubes()
{
// initialize w/ a basic sphere example
Implicit = new ImplicitSphere3d();
Bounds = new AxisAlignedBox3d(Vector3d.Zero, 8);
CubeSize = 0.25;
}
public WindingFieldImplicit(ImplicitFunction3d wf, double isoValue)
{
WindingF = wf;
IsoValue = isoValue;
}
protected virtual void compute_hollow()
{
double offset_distance = -wall_thickness;
if (cached_sdf == null ||
wall_thickness > cached_sdf_max_offset ||
grid_cell_size != cached_sdf.CellSize)
{
DMesh3 meshIn = MeshSource.GetDMeshUnsafe();
int exact_cells = (int)((wall_thickness) / grid_cell_size) + 1;
// only use spatial DS if we are computing enough cells
DMeshAABBTree3 use_spatial = GenerateClosedMeshOp.MeshSDFShouldUseSpatial(input_spatial, exact_cells, grid_cell_size, input_mesh_edge_stats.z);
MeshSignedDistanceGrid sdf = new MeshSignedDistanceGrid(meshIn, grid_cell_size, use_spatial)
{
ExactBandWidth = exact_cells
};
if (use_spatial != null)
{
sdf.NarrowBandMaxDistance = wall_thickness + grid_cell_size;
sdf.ComputeMode = MeshSignedDistanceGrid.ComputeModes.NarrowBand_SpatialFloodFill;
}
sdf.CancelF = is_invalidated;
sdf.Compute();
if (is_invalidated())
{
return;
}
cached_sdf = sdf;
cached_sdf_max_offset = wall_thickness;
cached_sdf_bounds = meshIn.CachedBounds;
}
var iso = new DenseGridTrilinearImplicit(cached_sdf.Grid, cached_sdf.GridOrigin, cached_sdf.CellSize);
ImplicitOffset3d shell_field = new ImplicitOffset3d()
{
A = iso, Offset = offset_distance
};
ImplicitFunction3d use_iso = shell_field;
if (enable_infill)
{
GridDistanceField grid_df = new GridDistanceField()
{
CellSize = infill_spacing,
Radius = infill_thickness * 0.5,
Origin = cached_sdf.GridOrigin
};
ImplicitDifference3d diff = new ImplicitDifference3d()
{
A = shell_field, B = grid_df
};
use_iso = diff;
}
MarchingCubes c = new MarchingCubes();
c.Implicit = use_iso;
c.IsoValue = 0;
c.Bounds = cached_sdf_bounds;
c.CubeSize = mesh_cell_size;
c.Bounds.Expand(offset_distance + 3 * c.CubeSize);
c.RootMode = MarchingCubes.RootfindingModes.LerpSteps;
c.RootModeSteps = 5;
c.CancelF = is_invalidated;
c.Generate();
if (is_invalidated())
{
return;
}
Reducer r = new Reducer(c.Mesh);
r.FastCollapsePass(c.CubeSize * 0.5, 3, true);
if (is_invalidated())
{
return;
}
//r.ReduceToTriangleCount(c.Mesh.TriangleCount / 5);
//if (is_invalidated())
// return;
if (min_component_volume > 0)
{
MeshEditor.RemoveSmallComponents(c.Mesh, min_component_volume, min_component_volume);
}
if (is_invalidated())
{
return;
}
c.Mesh.AttachMetadata("is_partial", new object());
ResultMesh = c.Mesh;
}
