Fix GSplat LOD re-evaluation when params change via frame:ready event

examples/src/examples/gaussian-splatting/lod-streaming.example.mjs

@@ -173,6 +173,25 @@ assetListLoader.load(() => {
     };
 
     applyPreset();
+
+    // Start with lowest LOD only for fast initial load
+    const lodLevels = gs.resource?.octree?.lodLevels;
+    if (lodLevels) {
+        const worstLod = lodLevels - 1;
+        app.scene.gsplat.lodRangeMin = worstLod;
+        app.scene.gsplat.lodRangeMax = worstLod;
+    }
+
+    // When lowest LOD is fully loaded, switch to the normal quality range
+    const gsplatSystem = /** @type {any} */ (app.systems.gsplat);
+    const onFrameReady = (/** @type {any} */ camera, /** @type {any} */ layer, /** @type {boolean} */ ready, /** @type {number} */ loadingCount) => {
+        if (ready && loadingCount === 0) {
+            gsplatSystem.off('frame:ready', onFrameReady);
+            applyPreset();
+        }
+    };
+    gsplatSystem.on('frame:ready', onFrameReady);
+
     data.on('lodPreset:set', applyPreset);
 
     const applySplatBudget = () => {

src/scene/gsplat-unified/gsplat-manager.js

@@ -1530,6 +1530,13 @@ class GSplatManager {
         // fire frame:ready event
         this.fireFrameReadyEvent();
 
+        // If event listeners dirtied params (e.g. changed LOD range), ensure LOD is re-evaluated
+        if (this.scene.gsplat.dirty) {
+            for (const [, inst] of this.octreeInstances) {
+                inst.needsLodUpdate = true;
+            }
+        }
+
         // return the number of active splats for stats
         return sortedState ? sortedState.totalActiveSplats : 0;
     }