WebCAD/src/Add-on/loadfbx.ts

import { LoadingManager, Mesh, MeshNormalMaterial } from "three";
import { FBXLoader } from "three/examples/jsm/loaders/FBXLoader";
import { app } from "../ApplicationServices/Application";
import { FileSystem } from "../Common/FileSystem";
import { Command, CommandWrap } from "../Editor/CommandMachine";
import { GetBox, MoveMatrix } from "../Geometry/GeUtils";

export class Fbx implements Command
{
    async exec()
    {
        FileSystem.ChooseFile({
            filter: ".fbx", callback: async (files) =>
            {
                CommandWrap(() =>
                {
                    let m = new MeshNormalMaterial();

                    for (let i = 0; i < files.length; i++)
                    {
                        let f = files.item(i);
                        let reader = new FileReader();

                        // Closure to capture the file information.
                        reader.onload = (ev) =>
                        {
                            let manager = new LoadingManager();
                            let loader = new FBXLoader(manager);
                            let obj = loader.parse(reader.result as string, "");

                            obj.traverse(o =>
                            {
                                if (o.type === "Mesh")
                                {
                                    (<Mesh>o).material = m;
                                }
                            })

                            let box = GetBox(obj);
                            let mp = box.min.clone().negate();
                            obj.applyMatrix(MoveMatrix(mp));

                            obj.matrixWorldNeedsUpdate = true;

                            app.Viewer.Scene.add(obj);
                        }
                        // Read in the image file as a data URL.
                        reader.readAsArrayBuffer(f);
                    }
                }, "fbx");
            }
        });
    }
}