Base zoom speed on browser refresh rate

packages/engine/Source/Core/FpsTracker.js

@@ -0,0 +1,40 @@
+import destroyObject from "../Core/destroyObject.js";
+import getTimestamp from "../Core/getTimestamp.js";
+
+/**
+ * @private
+ */
+function FpsTracker(options) {
+  this._timeStamps = [];
+}
+
+/**
+ * Calculates average fps based on timeStamps of recently rendered frames
+ */
+FpsTracker.prototype.getAverageFps = function () {
+  if (this._timeStamps.length !== 10) {
+    return;
+  }
+  const elapsedTime = (this._timeStamps[0] - this._timeStamps[9]) / 9;
+  const fps = 1 / (elapsedTime / 1000);
+  return fps;
+};
+
+/**
+ * Adds the timestamp for the current frame to the queue
+ */
+FpsTracker.prototype.updateFrameTimeStamp = function () {
+  const time = getTimestamp();
+  this._timeStamps.unshift(time);
+  if (this._timeStamps.length > 10) {
+    this._timeStamps.pop();
+  }
+};
+
+/**
+ * Destroys the WebGL resources held by this object.
+ */
+FpsTracker.prototype.destroy = function () {
+  return destroyObject(this);
+};
+export default FpsTracker;

packages/engine/Source/Scene/Scene.js

@@ -77,6 +77,7 @@ import View from "./View.js";
 import DebugInspector from "./DebugInspector.js";
 import VoxelCell from "./VoxelCell.js";
 import VoxelPrimitive from "./VoxelPrimitive.js";
+import FpsTracker from "../Core/FpsTracker.js";
 
 const requestRenderAfterFrame = function (scene) {
   return function () {
@@ -162,6 +163,7 @@ function Scene(options) {
   this._frameState.scene3DOnly = defaultValue(options.scene3DOnly, false);
   this._removeCreditContainer = !hasCreditContainer;
   this._creditContainer = creditContainer;
+  this._fpsTracker = new FpsTracker();
 
   this._canvas = canvas;
   this._context = context;
@@ -4096,6 +4098,7 @@ Scene.prototype.render = function (time) {
       1.0
     );
     updateFrameNumber(this, frameNumber, time);
+    this._fpsTracker.updateFrameTimeStamp();
     frameState.newFrame = true;
   }
 

packages/engine/Source/Scene/ScreenSpaceCameraController.js

@@ -573,7 +573,15 @@ function handleZoom(
   const maxHeight = object.maximumZoomDistance;
 
   const minDistance = distanceMeasure - minHeight;
-  let zoomRate = zoomFactor * minDistance;
+
+  let fpsMultiplier = 1;
+  const fps = object._scene._fpsTracker.getAverageFps();
+  if (fps) {
+    fpsMultiplier = 30 / fps;
+  }
+
+  let zoomRate = zoomFactor * minDistance * fpsMultiplier;
+
   zoomRate = CesiumMath.clamp(
     zoomRate,
     object._minimumZoomRate,