public static List <Envelope> SliceAtHeight(MeshElement meshElement, double cutHeight, Boolean showDebugGeometry)
{
var bbox = new BBox3(TransformedVertices(meshElement.Mesh.Vertices, meshElement.Transform));
var bottom = bbox.Min.Z;
var top = bbox.Max.Z;
var solids = new List <Elements.Geometry.Solids.SolidOperation>();
var solid = new Elements.Geometry.Solids.Solid();
foreach (var face in meshElement.Mesh.Triangles)
{
var vertices = TransformedVertices(face.Vertices, meshElement.Transform);
solid.AddFace(new Polygon(vertices));
}
solids.Add(new Elements.Geometry.Solids.ConstructedSolid(solid));
var rep = new Representation(solids);
var env = new Envelope(Polygon.Rectangle(new Vector3(bbox.Min.X, bbox.Min.Y), new Vector3(bbox.Max.X, bbox.Max.Y)), bottom, top - bottom, Vector3.ZAxis, 0, new Transform(), _debugMaterial, rep, false, Guid.NewGuid(), "");
return(SliceAtHeight(env, cutHeight, showDebugGeometry));
}
public static List <Envelope> SliceAtHeight(Envelope envelope, double cutHeight, Boolean showDebugGeometry)
{
var debugMaterial = new Material("DebugSolid", new Color(1, 0, 0, 1));
var plane = new Plane(new Vector3(0, 0, cutHeight), Vector3.ZAxis);
var top = envelope.Elevation + envelope.Height;
var envelopesForBlockage = new List <Envelope>();
var newUpperSolids = new List <Elements.Geometry.Solids.SolidOperation>();
Polygon slice = null;
foreach (var solidOp in envelope.Representation.SolidOperations)
{
var intersections = new List <Vector3>();
var newUpperSolid = new Elements.Geometry.Solids.Solid();
foreach (var face in solidOp.Solid.Faces)
{
var polygon = face.Value.Outer.ToPolygon();
if (solidOp.LocalTransform != null)
{
polygon = (Polygon)polygon.Transformed(solidOp.LocalTransform);
}
if (envelope.Transform != null)
{
polygon = (Polygon)polygon.Transformed(envelope.Transform);
}
var faceIntersections = new List <Vector3>();
foreach (var segment in polygon.Segments())
{
if (segment.Intersects(plane, out var intersection))
{
intersections.Add(intersection);
faceIntersections.Add(intersection);
}
}
if (faceIntersections.Count == 0)
{
if (polygon.Centroid().Z > cutHeight)
{
newUpperSolid.AddFace(polygon);
}
}
else if (faceIntersections.Count > 1)
{
faceIntersections = faceIntersections.OrderBy(p => p.X).ThenBy(p => p.Y).ToList();
var splitLine = new Polyline(faceIntersections);
var splits = polygon.Split(splitLine);
foreach (var split in splits)
{
if (split.Centroid().Z > cutHeight)
{
newUpperSolid.AddFace(split);
}
}
}
}
if (intersections.Count >= 3)
{
slice = ConvexHull.FromPoints(intersections);
slice = slice.Project(new Plane(new Vector3(), Vector3.ZAxis));
}
else if (intersections.Count > 0)
{
Console.WriteLine($"Failed to intersect polygon for East Midtown: Found {intersections.Count} point");
}
newUpperSolids.Add(new Elements.Geometry.Solids.ConstructedSolid(newUpperSolid));
}
if (slice != null)
{
var extrude1 = new Elements.Geometry.Solids.Extrude(slice, cutHeight, Vector3.ZAxis, false);
var rep1 = new Representation(new List <Elements.Geometry.Solids.SolidOperation>()
{
extrude1
});
var env1 = new Envelope(slice, 0, cutHeight, Vector3.ZAxis, 0, new Transform(), _debugMaterial, rep1, false, Guid.NewGuid(), "");
envelopesForBlockage.Add(env1);
var rep2 = new Representation(newUpperSolids);
var env2 = new Envelope(slice, 0, cutHeight, Vector3.ZAxis, 0, new Transform(), _debugMaterial, rep2, false, Guid.NewGuid(), "");
envelopesForBlockage.Add(env2);
if (showDebugGeometry)
{
Model.AddElement(env1);
Model.AddElement(env2);
}
}
return(envelopesForBlockage);
}