make getHeight pick in 3D mode

Source/Core/TerrainMesh.js

@@ -202,13 +202,14 @@ TerrainMesh.prototype.pickRay = function (
 
   const hasOctree = !!this._octreeTrianglePicking;
   const canUseOctree =
+    hasOctree &&
     // 3d mode only
     mode === SceneMode.SCENE3D /* 3d mode only*/ &&
     // the octree is baked for default terrain exaggeration, so we can only trust its result when we're
     //  not using terrain exaggeration
     this.encoding.exaggeration === 1;
 
-  if (hasOctree && canUseOctree) {
+  if (canUseOctree) {
     newPickValue = this._octreeTrianglePicking.rayIntersect(
       ray,
       cullBackFaces,
@@ -217,7 +218,10 @@ TerrainMesh.prototype.pickRay = function (
     );
   }
 
-  if (!window.disableDefaultPickStrategy) {
+  if (!window.disableDefaultPickStrategy || !canUseOctree) {
+    // if we've not elected to disable the default pick strategy entirely;
+    //  or we can't use the octree, so we have no other choice, then
+    //  use the default pick strategy
     oldPickValue = this._defaultPickStrategy.rayIntersect(
       ray,
       cullBackFaces,

Source/Scene/Globe.js

@@ -775,7 +775,7 @@ Globe.prototype.pickWorldCoordinates = function (
   for (i = 0; i < length; ++i) {
     intersection = sphereIntersections[i].pick(
       ray,
-      scene.frameState,
+      scene.mode,
       scene.mapProjection,
       cullBackFaces,
       result
@@ -938,8 +938,9 @@ Globe.prototype.getHeight = function (cartographic) {
 
   const intersection = tile.data.pick(
     ray,
-    // why is mode passed as undefined? I'm not sure, it's always been this way
-    undefined,
+    // If you're asking for globe "height", you're probably expecting the answer
+    //  with respect to 3D mode, not whatever mode the scene is currently in
+    SceneMode.SCENE3D,
     projection,
     false,
     scratchGetHeightIntersection