Cesium3DTilesetStatistics improvements

CHANGES.md

@@ -17,6 +17,7 @@
 - Improved performance of `scene.drillPick`. [#12916](https://github.com/CesiumGS/cesium/pull/12916)
 - Improved performance when removing primitives. [#3018](https://github.com/CesiumGS/cesium/pull/3018)
 - Improved performance of terrain Quadtree handling of custom data [#12907](https://github.com/CesiumGS/cesium/pull/12907)
+- Improved rendering performance when a 3D tileset is loaded [#12974](https://github.com/CesiumGS/cesium/pull/12974)
 
 ## 1.134.1 - 2025-10-10
 

packages/engine/Source/Scene/Cesium3DTileset.js

@@ -269,11 +269,13 @@ function Cesium3DTileset(options) {
   this._addHeightCallbacks = [];
 
   this._statistics = new Cesium3DTilesetStatistics();
-  this._statisticsLast = new Cesium3DTilesetStatistics();
+  this._statisticsLast = Cesium3DTilesetStatistics.snapshot(this._statistics);
   this._statisticsPerPass = new Array(Cesium3DTilePass.NUMBER_OF_PASSES);
 
   for (let i = 0; i < Cesium3DTilePass.NUMBER_OF_PASSES; ++i) {
-    this._statisticsPerPass[i] = new Cesium3DTilesetStatistics();
+    this._statisticsPerPass[i] = Cesium3DTilesetStatistics.snapshot(
+      this._statistics,
+    );
   }
 
   this._requestedTilesInFlight = [];
@@ -3285,7 +3287,7 @@ function raiseLoadProgressEvent(tileset, frameState) {
   const lastNumberOfPendingRequest = statisticsLast.numberOfPendingRequests;
   const lastNumberOfTilesProcessing = statisticsLast.numberOfTilesProcessing;
 
-  Cesium3DTilesetStatistics.clone(statistics, statisticsLast);
+  Cesium3DTilesetStatistics.snapshot(statistics, statisticsLast);
 
   const progressChanged =
     numberOfPendingRequests !== lastNumberOfPendingRequest ||
@@ -3371,7 +3373,7 @@ function detectModelMatrixChanged(tileset, frameState) {
  * @private
  * @param {Cesium3DTileset} tileset
  * @param {FrameState} frameState
- * @param {Cesium3DTilesetStatistics} passStatistics
+ * @param {Cesium3DTilesetStatisticsSnapshot} passStatistics
  * @param {object} passOptions
  * @returns {boolean}
  */
@@ -3408,7 +3410,7 @@ function update(tileset, frameState, passStatistics, passOptions) {
   updateTiles(tileset, frameState, passOptions);
 
   // Update pass statistics
-  Cesium3DTilesetStatistics.clone(statistics, passStatistics);
+  Cesium3DTilesetStatistics.snapshot(statistics, passStatistics);
 
   if (passOptions.isRender) {
     const credits = tileset._credits;

packages/engine/Source/Scene/Cesium3DTilesetStatistics.js

@@ -4,7 +4,7 @@ import Model3DTileContent from "./Model/Model3DTileContent.js";
 /**
  * @private
  */
-function Cesium3DTilesetStatistics() {
+function Cesium3DTilesetStatisticsSnapshot() {
   // Rendering statistics
   this.selected = 0;
   this.visited = 0;
@@ -30,10 +30,17 @@ function Cesium3DTilesetStatistics() {
   // Memory statistics
   this.geometryByteLength = 0;
   this.texturesByteLength = 0;
-  this.texturesReferenceCounterById = {};
   this.batchTableByteLength = 0; // batch textures and any binary metadata properties not otherwise accounted for
 }
 
+/**
+ * @private
+ */
+function Cesium3DTilesetStatistics() {
+  Cesium3DTilesetStatisticsSnapshot.call(this);
+  this.texturesReferenceCounterById = new Map();
+}
+
 Cesium3DTilesetStatistics.prototype.clear = function () {
   this.selected = 0;
   this.visited = 0;
@@ -100,12 +107,12 @@ Cesium3DTilesetStatistics.prototype.incrementLoadCounts = function (content) {
     const textureIds = content.getTextureIds();
     for (const textureId of textureIds) {
       const referenceCounter =
-        this.texturesReferenceCounterById[textureId] ?? 0;
+        this.texturesReferenceCounterById.get(textureId) ?? 0;
       if (referenceCounter === 0) {
         const textureByteLength = content.getTextureByteLengthById(textureId);
         this.texturesByteLength += textureByteLength;
       }
-      this.texturesReferenceCounterById[textureId] = referenceCounter + 1;
+      this.texturesReferenceCounterById.set(textureId, referenceCounter + 1);
     }
   }
 
@@ -146,13 +153,13 @@ Cesium3DTilesetStatistics.prototype.decrementLoadCounts = function (content) {
     // total textures byte length
     const textureIds = content.getTextureIds();
     for (const textureId of textureIds) {
-      const referenceCounter = this.texturesReferenceCounterById[textureId];
+      const referenceCounter = this.texturesReferenceCounterById.get(textureId);
       if (referenceCounter === 1) {
-        delete this.texturesReferenceCounterById[textureId];
+        this.texturesReferenceCounterById.delete(textureId);
         const textureByteLength = content.getTextureByteLengthById(textureId);
         this.texturesByteLength -= textureByteLength;
       } else {
-        this.texturesReferenceCounterById[textureId] = referenceCounter - 1;
+        this.texturesReferenceCounterById.set(textureId, referenceCounter - 1);
       }
     }
   }
@@ -166,7 +173,15 @@ Cesium3DTilesetStatistics.prototype.decrementLoadCounts = function (content) {
   }
 };
 
-Cesium3DTilesetStatistics.clone = function (statistics, result) {
+/**
+ * @param {Cesium3DTilesetStatistics} statistics
+ * @param {Cesium3DTilesetStatisticsSnapshot} result
+ * @returns {Cesium3DTilesetStatisticsSnapshot}
+ */
+Cesium3DTilesetStatistics.snapshot = function (
+  statistics,
+  result = new Cesium3DTilesetStatisticsSnapshot(),
+) {
   result.selected = statistics.selected;
   result.visited = statistics.visited;
   result.numberOfCommands = statistics.numberOfCommands;
@@ -187,9 +202,18 @@ Cesium3DTilesetStatistics.clone = function (statistics, result) {
     statistics.numberOfTilesCulledWithChildrenUnion;
   result.geometryByteLength = statistics.geometryByteLength;
   result.texturesByteLength = statistics.texturesByteLength;
-  result.texturesReferenceCounterById = {
-    ...statistics.texturesReferenceCounterById,
-  };
   result.batchTableByteLength = statistics.batchTableByteLength;
+
+  return result;
+};
+
+Cesium3DTilesetStatistics.clone = function (
+  statistics,
+  result = new Cesium3DTilesetStatistics(),
+) {
+  Cesium3DTilesetStatistics.snapshot(statistics, result);
+  result.texturesReferenceCounterById = new Map(
+    statistics.texturesReferenceCounterById,
+  );
 };
 export default Cesium3DTilesetStatistics;