faster multi-object load, faster updates and better orthographic camera at different scales

frontend/misc/scene.ts

@@ -6,11 +6,14 @@ import {Vector3} from "three/src/math/Vector3.js"
 import {Box3} from "three/src/math/Box3.js"
 import {Matrix4} from "three/src/math/Matrix4.js"
 
+let latestModel: string | null = null;
+
 /** This class helps manage SceneManagerData. All methods are static to support reactivity... */
 export class SceneMgr {
     /** Loads a GLB model from a URL and adds it to the viewer or replaces it if the names match */
     static async loadModel(sceneUrl: Ref<string>, document: Document, name: string, url: string): Promise<Document> {
         let loadStart = performance.now();
+        latestModel = name; // To help load helpers only once per model load batch
 
         // Start merging into the current document, replacing or adding as needed
         document = await mergePartial(url, name, document);
@@ -19,8 +22,12 @@ export class SceneMgr {
 
         if (name !== extrasNameValueHelpers) {
             // Reload the helpers to fit the new model
-            // TODO: Only reload the helpers after a few milliseconds of no more models being added/removed
-            document = await this.reloadHelpers(sceneUrl, document);
+            // Only reload the helpers after a few milliseconds of no more models being added/removed
+            setTimeout(async () => {
+                if (name === latestModel) {
+                    document = await this.reloadHelpers(sceneUrl, document);
+                }
+            }, 10)
         } else {
             // Display the final fully loaded model
             let displayStart = performance.now();