Update IFCLoader

[agviegas]

Latest updates from IFC.js, which are a lot. Some of them are:

• Faster query of spatial tree for the scene.
• Faster property fetch.
• More geometry support.
• Bigger files support (improved WASM memory allocation).
• Faster picking. We have made three-mesh-bvh completely optional. The users can select and get all the information of all the objects without that library, although for bigger models they can optionally use it to enhance the selection speed. Users can use it with just one line.

[mrdoob]

Thanks!

[mrdoob]

IFCLoader returns a single Mesh now then?

[agviegas]

To be precise, it retuns a single mesh and an API to work with that mesh.

In the beginning we were generating an object3d containing one mesh per item in the IFC file, but we found that this was already too laggy in medium sized files. The solution we came up with was generating only one single mesh (with one group per material), which dramatically increased the performance. That's the reason why we provide an API; to be able to access the individual elements, highlight them, get their properties, etc. That way, users can both have big models at 60 fps and still be able to work with individual items, as if they were separate meshes.

[mrdoob]

I see...

How about making IFCLoader return a IFCModel that extends Mesh then?

Then we can just do:

scene.add( model );

[agviegas]

We don't mind, but we would like a firm decision before changing the API and documentation again 😅 We have already made the API accessible from the IfcModel instances, not only from the IfcLoader. If we make the IfcLoader return an IfcMesh, should we provide each IfcMesh with all the methods of the API? For example: IfcMesh.getExpressID() .

[mrdoob]

Yes, sorry...

When I suggested returning a Group instead of a Scene I was not aware that the the Scene had only one child.

We could follow GLTFLoader approach which returns an object:

loader.load( 'foo.ifc', function ( ifc /* { manager : IFCManager, mesh : Mesh } */ ) {

    const mesh = ifc.mesh;
    scene.add( ifc.mesh );

    const manager = ifc.manager;
    const id = manager.getExpressId( mesh.geometry );

} );

This approach would also be backwards compatible.

[agviegas]

No worries! Sounds good, we'll do that 👌

[agviegas]

Does this look correct?

export class IFCModel extends Mesh {
    modelID = modelIdCounter++;
    mesh = this;

    constructor(geometry: BufferGeometry, materials: Material | Material[], public ifcManager: IFCManager) {
        super(geometry, materials);
    }
}

You can add IFCModels directly to the scene, and also call the IFC methods directly from them through their ifcManager property. The mesh property is to maintain the back/compatibility until we release the next major version.

[mrdoob]

This seems safer?

export class IFCModel extends Mesh {
    modelID = modelIdCounter++;
    mesh = this;
    manager = null;

    setIFCManager( manager ) {
        this.manager = manager;
    }
}