Merge pull request #9678 from CesiumGS/revert-9657-revert-9652-distan…

…ce-camera-fix

Update TileBoundingRegion.distanceToCamera to use OBB distance in 3D

CHANGES.md

@@ -6,6 +6,7 @@
 
 ##### Fixes :wrench:
 
+- Fixed an issue in `TileBoundingRegion.distanceToCamera` that caused incorrect results when the camera was on the opposite site of the globe. [#9678](https://github.com/CesiumGS/cesium/pull/9678)
 - Fixes an error with removing a CZML datasource when the clock interval has a duration of zero. [#9637](https://github.com/CesiumGS/cesium/pull/9637)
 - Fixed the ability to set a material's image to `undefined` and `Material.DefaultImageId`. [#9644](https://github.com/CesiumGS/cesium/pull/9644)
 - Fixed the calculation of `OrientedBoundingBox.distancedSquaredTo` such that they handle `halfAxes` with magnitudes near zero. [#9670](https://github.com/CesiumGS/cesium/pull/9670)

Source/Scene/TileBoundingRegion.js

@@ -4,6 +4,7 @@ import Cartographic from "../Core/Cartographic.js";
 import Check from "../Core/Check.js";
 import ColorGeometryInstanceAttribute from "../Core/ColorGeometryInstanceAttribute.js";
 import defaultValue from "../Core/defaultValue.js";
+import defined from "../Core/defined.js";
 import Ellipsoid from "../Core/Ellipsoid.js";
 import GeometryInstance from "../Core/GeometryInstance.js";
 import IntersectionTests from "../Core/IntersectionTests.js";
@@ -299,39 +300,30 @@ var negativeUnitY = new Cartesian3(0.0, -1.0, 0.0);
 var negativeUnitZ = new Cartesian3(0.0, 0.0, -1.0);
 var vectorScratch = new Cartesian3();
 
-/**
- * Gets the distance from the camera to the closest point on the tile.  This is used for level of detail selection.
- *
- * @param {FrameState} frameState The state information of the current rendering frame.
- * @returns {Number} The distance from the camera to the closest point on the tile, in meters.
- */
-TileBoundingRegion.prototype.distanceToCamera = function (frameState) {
-  //>>includeStart('debug', pragmas.debug);
-  Check.defined("frameState", frameState);
-  //>>includeEnd('debug');
+function distanceToCameraRegion(tileBB, frameState) {
   var camera = frameState.camera;
   var cameraCartesianPosition = camera.positionWC;
   var cameraCartographicPosition = camera.positionCartographic;
 
   var result = 0.0;
-  if (!Rectangle.contains(this.rectangle, cameraCartographicPosition)) {
-    var southwestCornerCartesian = this.southwestCornerCartesian;
-    var northeastCornerCartesian = this.northeastCornerCartesian;
-    var westNormal = this.westNormal;
-    var southNormal = this.southNormal;
-    var eastNormal = this.eastNormal;
-    var northNormal = this.northNormal;
+  if (!Rectangle.contains(tileBB.rectangle, cameraCartographicPosition)) {
+    var southwestCornerCartesian = tileBB.southwestCornerCartesian;
+    var northeastCornerCartesian = tileBB.northeastCornerCartesian;
+    var westNormal = tileBB.westNormal;
+    var southNormal = tileBB.southNormal;
+    var eastNormal = tileBB.eastNormal;
+    var northNormal = tileBB.northNormal;
 
     if (frameState.mode !== SceneMode.SCENE3D) {
       southwestCornerCartesian = frameState.mapProjection.project(
-        Rectangle.southwest(this.rectangle),
+        Rectangle.southwest(tileBB.rectangle),
         southwestCornerScratch
       );
       southwestCornerCartesian.z = southwestCornerCartesian.y;
       southwestCornerCartesian.y = southwestCornerCartesian.x;
       southwestCornerCartesian.x = 0.0;
       northeastCornerCartesian = frameState.mapProjection.project(
-        Rectangle.northeast(this.rectangle),
+        Rectangle.northeast(tileBB.rectangle),
         northeastCornerScratch
       );
       northeastCornerCartesian.z = northeastCornerCartesian.y;
@@ -389,8 +381,8 @@ TileBoundingRegion.prototype.distanceToCamera = function (frameState) {
   var maximumHeight;
   if (frameState.mode === SceneMode.SCENE3D) {
     cameraHeight = cameraCartographicPosition.height;
-    minimumHeight = this.minimumHeight;
-    maximumHeight = this.maximumHeight;
+    minimumHeight = tileBB.minimumHeight;
+    maximumHeight = tileBB.maximumHeight;
   } else {
     cameraHeight = cameraCartesianPosition.x;
     minimumHeight = 0.0;
@@ -406,6 +398,30 @@ TileBoundingRegion.prototype.distanceToCamera = function (frameState) {
   }
 
   return Math.sqrt(result);
+}
+
+/**
+ * Gets the distance from the camera to the closest point on the tile.  This is used for level of detail selection.
+ *
+ * @param {FrameState} frameState The state information of the current rendering frame.
+ * @returns {Number} The distance from the camera to the closest point on the tile, in meters.
+ */
+TileBoundingRegion.prototype.distanceToCamera = function (frameState) {
+  //>>includeStart('debug', pragmas.debug);
+  Check.defined("frameState", frameState);
+  //>>includeEnd('debug');
+
+  var regionResult = distanceToCameraRegion(this, frameState);
+  if (
+    frameState.mode === SceneMode.SCENE3D &&
+    defined(this._orientedBoundingBox)
+  ) {
+    var obbResult = Math.sqrt(
+      this._orientedBoundingBox.distanceSquaredTo(frameState.camera.positionWC)
+    );
+    return Math.max(regionResult, obbResult);
+  }
+  return regionResult;
 };
 
 /**