/// <summary>
/// Method for mesh decimation
/// </summary>
/// <param name="meshStore">mesh data</param>
/// <param name="targetTriangleCount">target triangle count for decimation</param>
public static void Decimate(ref MeshStore meshStore, int targetTriangleCount)
{
// extract origin mesh data and create mesh instance
Vector3d[] vertices = new Vector3d[meshStore.Vertexes.Count / 3];
for (int i = 0, j = 0; i < meshStore.Vertexes.Count; i += 3, ++j)
{
vertices[j] = new Vector3d(meshStore.Vertexes[i], meshStore.Vertexes[i + 1], meshStore.Vertexes[i + 2]);
}
Mesh sourceMesh = new Mesh(vertices, meshStore.Indexes.ToArray());
// decimate mesh
var algorithm = MeshDecimation.CreateAlgorithm(Algorithm.Default);
algorithm.Verbose = true;
Mesh destMesh = MeshDecimation.DecimateMesh(algorithm, sourceMesh, targetTriangleCount);
// change meshstore
meshStore.Indexes = destMesh.Indices.ToList();
List <double> newVertices = new List <double>();
foreach (Vector3d vec in destMesh.Vertices)
{
newVertices.Add(vec.x);
newVertices.Add(vec.y);
newVertices.Add(vec.z);
}
meshStore.Vertexes = newVertices;
}
/// <summary>
/// Extract Geometries from IFC file.
/// </summary>
/// <param name="model">IfcStore model.</param>
/// <param name="geometries">Geometries data.</param>
/// <param name="modelBoundingBox">Bounding box of the ifc model.</param>
public static void ExtractGeometries(IfcStore model, ref Dictionary <string, GeometryStore> geometries, ref XbimRect3D modelBoundingBox)
{
// context is used to extract geometry data
var context = new Xbim3DModelContext(model);
var meter = context.Model.ModelFactors.OneMeter;
context.CreateContext();
// start to extract geometry data
var instances = context.ShapeInstances();
XbimColourMap colorMap = new XbimColourMap();
foreach (var instance in instances) // each instance is a mesh
{
MeshStore meshStore = new MeshStore();
// get the color of this mesh
var ss = model.Instances[instance.StyleLabel] as IIfcSurfaceStyle;
XbimColour color = XbimColour.DefaultColour;
if (ss != null)
{
var texture = XbimTexture.Create(ss);
color = texture.ColourMap.FirstOrDefault();
}
else
{
var styleId = instance.StyleLabel > 0 ? instance.StyleLabel : instance.IfcTypeId;
var theType = model.Metadata.GetType((short)styleId);
color = colorMap[theType.Name];
}
meshStore.Color = string.Format("{0},{1},{2},{3}", (int)(color.Red * 255), (int)(color.Green * 255), (int)(color.Blue * 255), color.Alpha * 255);
var geometry = context.ShapeGeometry(instance);
var data = (geometry as IXbimShapeGeometryData).ShapeData;
// multiple geometry may belong to one product, like frame and glass belong to a ifcwindow
var product = model.Instances[instance.IfcProductLabel] as IIfcProduct;
if (!geometries.ContainsKey(product.GlobalId))
{
geometries.Add(product.GlobalId, new GeometryStore(product.GlobalId, product.Name));
}
var geometryStore = geometries[product.GlobalId];
// reading the real geometry data
using (var stream = new MemoryStream(data))
{
using (var reader = new BinaryReader(stream))
{
// triangle the instance and transform it to the correct position
var mesh = reader.ReadShapeTriangulation();
mesh = mesh.Transform(instance.Transformation);
// geometry data
var verticesData = new List <double>();
var normalsData = new List <double>();
var indexesData = new List <int>();
// bouding box for instance.
double minX = double.MaxValue, minY = double.MaxValue, minZ = double.MaxValue,
maxX = double.MinValue, maxY = double.MinValue, maxZ = double.MinValue;
var faces = mesh.Faces as List <XbimFaceTriangulation>;
foreach (var face in faces)
{
foreach (var indice in face.Indices)
{
indexesData.Add(indice);
}
foreach (var normal in face.Normals)
{
normalsData.Add(normal.Normal.X);
normalsData.Add(normal.Normal.Y);
normalsData.Add(normal.Normal.Z);
}
}
var vertices = mesh.Vertices as List <XbimPoint3D>;
foreach (var point in vertices)
{
double x = point.X / meter, y = point.Y / meter, z = point.Z / meter;
verticesData.Add(x); // convert to meter
verticesData.Add(y);
verticesData.Add(z);
// update bounding box
minX = Math.Min(minX, x);
minY = Math.Min(minY, y);
minZ = Math.Min(minZ, z);
maxX = Math.Max(maxX, x);
maxY = Math.Max(maxY, y);
maxZ = Math.Max(maxZ, z);
}
if (minX == double.MaxValue || minY == double.MaxValue || minZ == double.MaxValue ||
maxX == double.MinValue || maxY == double.MinValue || maxZ == double.MinValue)
{
throw new Exception("Invalid Boundingbox");
}
// do not trust instance.BoundingBox, it seems to be wrong.
XbimRect3D bbox = new XbimRect3D(minX, minY, minZ, maxX - minX, maxY - minY, maxZ - minZ);
// update boundingbox of current geometryStore
geometryStore.BoundBox = GeometryStore.Union(geometryStore.BoundBox, bbox);
// update boundingbox of ifc model
modelBoundingBox = GeometryStore.Union(modelBoundingBox, bbox);
meshStore.Vertexes = verticesData;
meshStore.Normals = normalsData;
meshStore.Indexes = indexesData;
}
}
geometryStore.Meshes.Add(meshStore);
}
}
