Lots of frontend improvements like keeping camera position on changes, avoid flickering on live updates, smooth gizmo animations, proper ortho camera movement, and enabling move by tap when not selecting.

frontend/viewer/ModelViewerWrapper.vue

@@ -1,8 +1,9 @@
-<script setup lang="ts">
+<script lang="ts" setup>
 import {settings} from "../misc/settings";
 import {inject, onMounted, type Ref, ref, watch} from "vue";
-import {VList, VListItem} from "vuetify/lib/components/index.mjs";
 import {$renderer, $scene} from "@google/model-viewer/lib/model-viewer-base";
+import {$controls} from '@google/model-viewer/lib/features/controls.js';
+import {type SmoothControls} from '@google/model-viewer/lib/three-components/SmoothControls';
 import {ModelViewerElement} from '@google/model-viewer';
 import type {ModelScene} from "@google/model-viewer/lib/three-components/ModelScene";
 import {Hotspot} from "@google/model-viewer/lib/three-components/Hotspot";
@@ -19,31 +20,63 @@ BufferGeometry.prototype.disposeBoundsTree = disposeBoundsTree;
 //@ts-ignore
 Mesh.prototype.raycast = acceleratedRaycast;
 
-const emit = defineEmits<{ load: [] }>()
-
 const props = defineProps<{ src: string }>();
 
 const elem = ref<ModelViewerElement | null>(null);
 const scene = ref<ModelScene | null>(null);
 const renderer = ref<Renderer | null>(null);
+const controls = ref<SmoothControls | null>(null);
 
+
+let lastCameraTargetPosition: Vector3 | undefined = undefined;
+let lastCameraZoom: number | undefined = undefined;
+let lastCameraUrl = props.src.toString();
 onMounted(() => {
   if (!elem.value) return;
-  elem.value.addEventListener('load', async () => {
+  elem.value.addEventListener('before-render', () => {
     if (!elem.value) return;
-    // Delete the initial load banner
-    let banner = elem.value.querySelector('.initial-load-banner');
-    if (banner) banner.remove();
-    // Set the scene and renderer
+    // Extract internals of model-viewer in order to hack unsupported features
     scene.value = elem.value[$scene] as ModelScene;
     renderer.value = elem.value[$renderer] as Renderer;
-    // Emit the load event
-    emit('load')
+    controls.value = (elem.value as any)[$controls] as SmoothControls;
+    // Recover the camera position if it was set before
+    if (lastCameraTargetPosition) {
+      // console.log("RESTORING camera position?", lastCameraTargetPosition);
+      scene.value.setTarget(-lastCameraTargetPosition.x, -lastCameraTargetPosition.y, -lastCameraTargetPosition.z);
+      scene.value.jumpToGoal(); // Avoid move animation
+    }
+    (async () => {
+      let tries = 0
+      while (tries++ < 25) {
+        if (!lastCameraZoom || !elem.value?.getCameraOrbit()?.radius) break;
+        let change = lastCameraZoom - elem.value.getCameraOrbit().radius;
+        //console.log("Zooming to", lastCameraZoom, "from", elem.value.getCameraOrbit().radius, "change", change);
+        if (Math.abs(change) < 0.001) break;
+        elem.value.zoom(-Math.sign(change) * (Math.pow(Math.abs(change) + 1, 0.9) - 1)); // Arbitrary, experimental
+        elem.value.jumpCameraToGoal();
+        await elem.value.updateComplete;
+      }
+      //console.log("Ready to save!")
+      lastCameraUrl = props.src.toString();
+    })();
   });
   elem.value.addEventListener('camera-change', onCameraChange);
   elem.value.addEventListener('progress', (ev) => onProgress((ev as any).detail.totalProgress));
 });
 
+function onCameraChange() {
+  // Remember the camera position to keep it in case of scene changes
+  if (scene.value && props.src.toString() == lastCameraUrl) {  // Don't overwrite with initial unwanted positions
+    lastCameraTargetPosition = scene.value.target.position.clone();
+    lastCameraZoom = elem.value?.getCameraOrbit()?.radius;
+    //console.log("Saving camera?", lastCameraTargetPosition, lastCameraZoom);
+  }
+  // Also need to update the SVG overlay
+  for (let lineId in lines.value) {
+    onCameraChangeLine(lineId as any);
+  }
+}
+
 // Handles loading the events for <model-viewer>'s slotted progress bar
 const progressBar = ref<HTMLElement | null>(null);
 const updateBar = ref<HTMLElement | null>(null);
@@ -66,6 +99,17 @@ const onProgress = (totalProgress: number) => {
   }, 1000);
 };
 
+const poster = ref<string>("")
+const setPosterText = (newText: string) => {
+  poster.value = "data:image/svg+xml;charset=utf-8;base64," + btoa(
+      '<svg width="800" height="600" xmlns="http://www.w3.org/2000/svg" fill="gray">' +
+      '<text x="50%" y="0%" dominant-baseline="middle" text-anchor="middle" font-size="48px">' +
+      newText +
+      '</text>' +
+      '</svg>')
+}
+setPosterText("Loading...")
+
 class Line3DData {
   startHotspot: HTMLElement = document.body
   endHotspot: HTMLElement = document.body
@@ -118,13 +162,6 @@ function removeLine3D(id: number): boolean {
   return true;
 }
 
-function onCameraChange() {
-  // Need to update the SVG overlay
-  for (let lineId in lines.value) {
-    onCameraChangeLine(lineId as any);
-  }
-}
-
 let svg = ref<SVGElement | null>(null);
 
 function onCameraChangeLine(lineId: number) {
@@ -160,54 +197,47 @@ function entries(lines: { [id: number]: Line3DData }): [string, Line3DData][] {
   return Object.entries(lines);
 }
 
-defineExpose({elem, onElemReady, scene, renderer, addLine3D, removeLine3D, onProgress});
+defineExpose({elem, onElemReady, scene, renderer, controls, addLine3D, removeLine3D, onProgress, setPosterText});
 
 let {disableTap} = inject<{ disableTap: Ref<boolean> }>('disableTap')!!;
-watch(disableTap, (value) => {
-  // Rerender not auto triggered? This works anyway...
-  if (value) elem.value?.setAttribute('disable-tap', '');
-  else elem.value?.removeAttribute('disable-tap');
+watch(disableTap, (newDisableTap) => {
+  if (elem.value) elem.value.disableTap = newDisableTap;
 });
 </script>
 
 <template>
   <!-- The main 3D model viewer -->
-  <model-viewer ref="elem" style="width: 100%; height: 100%" :src="props.src" alt="The 3D model(s)" camera-controls
-                camera-orbit="30deg 75deg auto" max-camera-orbit="Infinity 180deg auto"
-                min-camera-orbit="-Infinity 0deg 5%" :disable-tap="disableTap" :exposure="settings.exposure"
-                :shadow-intensity="settings.shadowIntensity" interaction-prompt="none" :autoplay="settings.autoplay"
-                :ar="settings.arModes.length > 0" :ar-modes="settings.arModes" :skybox-image="settings.background"
-                :environment-image="settings.background">
+  <model-viewer ref="elem" :ar="settings.arModes.length > 0" :ar-modes="settings.arModes" :autoplay="settings.autoplay"
+                :environment-image="settings.background" :exposure="settings.exposure"
+                :orbit-sensitivity="settings.orbitSensitivity" :pan-sensitivity="settings.panSensitivity"
+                :poster="poster" :shadow-intensity="settings.shadowIntensity" :skybox-image="settings.background"
+                :src="props.src" :zoom-sensitivity="settings.zoomSensitivity" alt="The 3D model(s)" camera-controls
+                camera-orbit="30deg 75deg auto" interaction-prompt="none" max-camera-orbit="Infinity 180deg auto"
+                min-camera-orbit="-Infinity 0deg 5%" style="width: 100%; height: 100%">
     <slot></slot>
-    <!-- Display some information during initial load -->
-    <div class="annotation initial-load-banner">
-      Trying to load models from...
-      <v-list v-for="src in settings.preload" :key="src">
-        <v-list-item>{{ src }}</v-list-item>
-      </v-list>
-      <!-- Too much idle CPU usage: <loading></loading> -->
-    </div>
-
-    <!-- Customize the progress bar -->
-    <div class="progress-bar" slot="progress-bar" ref="progressBar">
-      <div class="update-bar" ref="updateBar"/>
+    <!-- Add a progress bar to the top of the model viewer -->
+    <div ref="progressBar" slot="progress-bar" class="progress-bar">
+      <div ref="updateBar" class="update-bar"/>
     </div>
   </model-viewer>
 
   <!-- The SVG overlay for fake 3D lines attached to the model -->
   <div class="overlay-svg-wrapper">
-    <svg ref="svg" class="overlay-svg" width="100%" height="100%" xmlns="http://www.w3.org/2000/svg">
+    <svg ref="svg" class="overlay-svg" height="100%" width="100%" xmlns="http://www.w3.org/2000/svg">
       <g v-for="[lineId, line] in entries(lines)" :key="lineId">
-        <line :x1="line.start2D[0]" :y1="line.start2D[1]" :x2="line.end2D[0]"
+        <line :x1="line.start2D[0]" :x2="line.end2D[0]" :y1="line.start2D[1]"
               :y2="line.end2D[1]" v-bind="line.lineAttrs"/>
         <g v-if="line.centerText !== undefined">
-          <rect :x="(line.start2D[0] + line.end2D[0]) / 2 - line.centerTextSize[0]/2 - 4"
-                :y="(line.start2D[1] + line.end2D[1]) / 2 - line.centerTextSize[1]/2 - 2"
-                :width="line.centerTextSize[0] + 8" :height="line.centerTextSize[1] + 4"
-                fill="gray" fill-opacity="0.75" rx="4" ry="4" stroke="black" v-if="line.centerText"/>
-          <text :x="(line.start2D[0] + line.end2D[0]) / 2" :y="(line.start2D[1] + line.end2D[1]) / 2"
-                text-anchor="middle" dominant-baseline="middle" font-size="16" fill="black"
-                :class="'line' + lineId + '_text'" v-if="line.centerText">
+          <rect v-if="line.centerText"
+                :height="line.centerTextSize[1] + 4"
+                :width="line.centerTextSize[0] + 8"
+                :x="(line.start2D[0] + line.end2D[0]) / 2 - line.centerTextSize[0]/2 - 4"
+                :y="(line.start2D[1] + line.end2D[1]) / 2 - line.centerTextSize[1]/2 - 2" fill="gray"
+                fill-opacity="0.75" rx="4" ry="4" stroke="black"/>
+          <text v-if="line.centerText" :class="'line' + lineId + '_text'"
+                :x="(line.start2D[0] + line.end2D[0]) / 2" :y="(line.start2D[1] + line.end2D[1]) / 2"
+                dominant-baseline="middle" fill="black"
+                font-size="16" text-anchor="middle">
             {{ line.centerText }}
           </text>
         </g>
@@ -242,17 +272,6 @@ watch(disableTap, (value) => {
   pointer-events: none;
 }
 
-.initial-load-banner {
-  width: 300px;
-  margin: auto;
-  margin-top: 3em;
-  overflow: hidden;
-}
-
-.initial-load-banner .v-list-item {
-  overflow: hidden;
-}
-
 .progress-bar {
   display: block;
   pointer-events: none;