/// <summary>
/// Exports a gltf file from a meshed model
/// </summary>
/// <param name="model">The model needs to have the geometry meshes already cached</param>
/// <param name="exclude">The types of elements that are going to be omitted (e.g. ifcSpaces).</param>
/// <param name="EntityLebels">Only entities in the collection are exported; if null exports the whole model</param>
/// <returns></returns>
public gltf.Gltf BuildInstancedScene(IModel model, XbimMatrix3D overallTransform, List <Type> exclude = null, HashSet <int> EntityLebels = null)
{
Init();
Dictionary <int, ShapeComponentIds> geometries = new Dictionary <int, ShapeComponentIds>();
// this needs a previously meshed xbim file.
//
var s = new Stopwatch();
s.Start();
int iCnt = 0;
Random r = new Random();
var excludedTypes = DefaultExclusions(model, exclude);
using (var geomStore = model.GeometryStore)
using (var geomReader = geomStore.BeginRead())
{
// process the materials and styles
var sstyleIds = geomReader.StyleIds;
foreach (var styleId in sstyleIds)
{
PrepareStyleMaterial(model, styleId);
}
int productLabel = 0;
var shapeInstances = GetShapeInstancesToRender(geomReader, excludedTypes, EntityLebels);
// foreach (var shapeInstance in shapeInstances.OrderBy(x=>x.IfcProductLabel))
gltf.Mesh targetMesh = null;
foreach (var shapeInstance in shapeInstances.OrderBy(x => x.IfcProductLabel))
{
if (CustomFilter != null)
{
var skip = CustomFilter(shapeInstance.IfcProductLabel, model);
if (skip)
{
continue;
}
}
// we start with a shape instance and then load its geometry.
// a product (e.g. wall or window) in the scene returns:
// - a node
// - pointing to a mesh, with a transform
// - 1 mesh
// - with as many mesh primitives as needed to render the different parts
// - pointers to the a material and accessors as needed
// - 3 accessors per primitive
// - vertices, normals, indices
// - bufferviews can be reused by different accessors
// - data in the buffer, of course
if (productLabel != shapeInstance.IfcProductLabel)
{
// need new product
// create node
var nodeIndex = _nodes.Count;
var entity = model.Instances[shapeInstance.IfcProductLabel] as IIfcProduct;
if (entity == null)
{ // fire error here.
}
var tnode = new gltf.Node();
tnode.Name = entity.Name + $" #{entity.EntityLabel}";
// instance transformation needs to be expressed in meters
//
var inModelTransf = XbimMatrix3D.Copy(shapeInstance.Transformation);
inModelTransf.OffsetX /= model.ModelFactors.OneMeter;
inModelTransf.OffsetY /= model.ModelFactors.OneMeter;
inModelTransf.OffsetZ /= model.ModelFactors.OneMeter;
// overalltransform is already expressed in meters
var tMat = XbimMatrix3D.Multiply(inModelTransf, overallTransform);
tnode.Matrix = tMat.ToFloatArray();
// create mesh
var meshIndex = _meshes.Count;
targetMesh = new gltf.Mesh
{
Name = $"Instance {productLabel}"
};
// link node to mesh
tnode.Mesh = meshIndex;
// add all to lists
_nodes.Add(tnode);
_meshes.Add(targetMesh);
}
// now the geometry
//
IXbimShapeGeometryData shapeGeom = geomReader.ShapeGeometry(shapeInstance.ShapeGeometryLabel);
if (shapeGeom.Format != (byte)XbimGeometryType.PolyhedronBinary)
{
continue;
}
// work out colour id;
// the colour is associated with the instance, not the geometry.
// positives are styles, negatives are types
var colId = shapeInstance.StyleLabel > 0
? shapeInstance.StyleLabel
: shapeInstance.IfcTypeId * -1;
int materialIndex;
if (!styleDic.TryGetValue(colId, out materialIndex))
{
// if the style is not available we build one by ExpressType
materialIndex = PrepareTypeMaterial(model, shapeInstance.IfcTypeId);
styleDic.Add(colId, materialIndex);
}
// note: at a first investigation it looks like the shapeInstance.Transformation is the same for all shapes of the same product
if (shapeGeom.ReferenceCount > 1)
{
// retain the information to reuse the map multiple times
//
// if g is not found in the dictionary then build it and add it
ShapeComponentIds components;
if (!geometries.TryGetValue(shapeGeom.ShapeLabel, out components))
{
// mesh
var xbimMesher = new XbimMesher();
xbimMesher.AddMesh(shapeGeom.ShapeData);
components = AddGeom(
xbimMesher.PositionsAsSingleList(model.ModelFactors.OneMeter),
xbimMesher.Indices,
xbimMesher.NormalsAsSingleList()
);
geometries.Add(shapeGeom.ShapeLabel, components);
}
if (components != null)
{
// var arr = GetTransformInMeters(model, shapeInstance);
AddComponentsToMesh(targetMesh, components, materialIndex);
}
}
else
{
// repeat the geometry only once
//
var xbimMesher = new XbimMesher();
xbimMesher.AddMesh(shapeGeom.ShapeData);
// var trsf = GetTransformInMeters(model, shapeInstance);
var components = AddGeom(
xbimMesher.PositionsAsSingleList(model.ModelFactors.OneMeter),
xbimMesher.Indices,
xbimMesher.NormalsAsSingleList()
);
AddComponentsToMesh(targetMesh, components, materialIndex);
}
iCnt++;
if (iCnt % 100 == 0)
{
Debug.WriteLine($"added {iCnt} elements in {s.ElapsedMilliseconds}ms.");
}
}
}
Debug.WriteLine($"added {iCnt} elements in {s.ElapsedMilliseconds}ms.");
return(Build());
}