3D Tiles Traversal cleanup

CHANGES.md

@@ -15,6 +15,12 @@ Change Log
 * Added optional `width` and `height` to `Scene.drillPick` for specifying a search area.
 
 ##### Fixes :wrench:
+* Several performance improvements and fixes to the 3D Tiles traversal code. [#6390](https://github.com/AnalyticalGraphicsInc/cesium/pull/6390)
+    * Improved load performance when `skipLevelOfDetail` is false.
+    * Fixed a bug that caused some skipped tiles to load when `skipLevelOfDetail` is true.
+    * Fixed pick statistics in the 3D Tiles Inspector.
+    * Fixed drawing of debug labels for external tilesets.
+    * Fixed drawing of debug outlines for empty tiles.
 * The Geocoder widget now takes terrain altitude into account when calculating its final destination.
 * The Viewer widget now takes terrain altitude into account when zooming or flying to imagery layers.
 * Fixed `getPickRay` in 2D. [#2480](https://github.com/AnalyticalGraphicsInc/cesium/issues/2480)

Source/Core/ManagedArray.js

@@ -74,21 +74,32 @@ define([
      * Sets the element at an index. Resizes the array if index is greater than the length of the array.
      *
      * @param {Number} index The index to set.
-     * @param {*} value The value to set at index.
+     * @param {*} element The element to set at index.
      */
-    ManagedArray.prototype.set = function(index, value) {
+    ManagedArray.prototype.set = function(index, element) {
         //>>includeStart('debug', pragmas.debug);
         Check.typeOf.number('index', index);
         //>>includeEnd('debug');
 
         if (index >= this.length) {
             this.length = index + 1;
         }
-        this._array[index] = value;
+        this._array[index] = element;
+    };
+
+    /**
+     * Returns the last element in the array without modifying the array.
+     *
+     * @returns {*} The last element in the array.
+     */
+    ManagedArray.prototype.peek = function() {
+        return this._array[this._length - 1];
     };
 
     /**
      * Push an element into the array.
+     *
+     * @param {*} element The element to push.
      */
     ManagedArray.prototype.push = function(element) {
         var index = this.length++;

Source/Scene/Batched3DModel3DTileContent.js

@@ -482,8 +482,7 @@ define([
         // If any commands were pushed, add derived commands
         var commandEnd = frameState.commandList.length;
         if ((commandStart < commandEnd) && (frameState.passes.render || frameState.passes.pick) && !defined(tileset.classificationType)) {
-            var finalResolution = this._tile._finalResolution;
-            this._batchTable.addDerivedCommands(frameState, commandStart, finalResolution);
+            this._batchTable.addDerivedCommands(frameState, commandStart);
         }
    };
 

Source/Scene/Cesium3DTile.js

@@ -2,6 +2,7 @@ define([
         '../Core/BoundingSphere',
         '../Core/Cartesian3',
         '../Core/Color',
+        '../Core/ColorGeometryInstanceAttribute',
         '../Core/CullingVolume',
         '../Core/defaultValue',
         '../Core/defined',
@@ -24,7 +25,6 @@ define([
         '../Core/Resource',
         '../Core/RuntimeError',
         '../ThirdParty/when',
-        './Cesium3DTileChildrenVisibility',
         './Cesium3DTileContentFactory',
         './Cesium3DTileContentState',
         './Cesium3DTileOptimizationHint',
@@ -38,6 +38,7 @@ define([
         BoundingSphere,
         Cartesian3,
         Color,
+        ColorGeometryInstanceAttribute,
         CullingVolume,
         defaultValue,
         defined,
@@ -60,7 +61,6 @@ define([
         Resource,
         RuntimeError,
         when,
-        Cesium3DTileChildrenVisibility,
         Cesium3DTileContentFactory,
         Cesium3DTileContentState,
         Cesium3DTileOptimizationHint,
@@ -235,19 +235,6 @@ define([
          */
         this.hasEmptyContent = hasEmptyContent;
 
-        /**
-         * When <code>true</code>, the tile's content is renderable.
-         * <p>
-         * This is <code>false</code> until the tile's content is loaded.
-         * </p>
-         *
-         * @type {Boolean}
-         * @readonly
-         *
-         * @private
-         */
-        this.hasRenderableContent = false;
-
         /**
          * When <code>true</code>, the tile's content points to an external tileset.
          * <p>
@@ -262,14 +249,16 @@ define([
         this.hasTilesetContent = false;
 
         /**
-         * The corresponding node in the cache replacement list.
+         * The node in the tileset's LRU cache, used to determine when to unload a tile's content.
+         *
+         * See {@link Cesium3DTilesetCache}
          *
          * @type {DoublyLinkedListNode}
          * @readonly
          *
          * @private
          */
-        this.replacementNode = undefined;
+        this.cacheNode = undefined;
 
         var expire = header.expire;
         var expireDuration;
@@ -295,15 +284,6 @@ define([
          */
         this.expireDate = expireDate;
 
-        /**
-         * Marks if the tile is selected this frame.
-         *
-         * @type {Boolean}
-         *
-         * @private
-         */
-        this.selected = false;
-
         /**
          * The time when a style was last applied to this tile.
          *
@@ -334,22 +314,27 @@ define([
 
         // Members that are updated every frame for tree traversal and rendering optimizations:
         this._distanceToCamera = 0;
-        this._visibilityPlaneMask = 0;
-        this._childrenVisibility = Cesium3DTileChildrenVisibility.VISIBLE;
-        this._lastSelectedFrameNumber = -1;
+        this._centerZDepth = 0;
         this._screenSpaceError = 0;
-        this._screenSpaceErrorComputedFrame = -1;
+        this._visibilityPlaneMask = 0;
+        this._visible = false;
+        this._inRequestVolume = false;
+
         this._finalResolution = true;
         this._depth = 0;
-        this._centerZDepth = 0;
         this._stackLength = 0;
-        this._selectedFrame = -1;
         this._selectionDepth = 0;
-        this._lastSelectionDepth = undefined;
-        this._requestedFrame = undefined;
-        this._lastVisitedFrame = undefined;
+
+        this._updatedVisibilityFrame = 0;
+        this._touchedFrame = 0;
+        this._visitedFrame = 0;
+        this._selectedFrame = 0;
+        this._requestedFrame = 0;
         this._ancestorWithContent = undefined;
-        this._ancestorWithLoadedContent = undefined;
+        this._ancestorWithContentAvailable = undefined;
+        this._refines = false;
+        this._shouldSelect = false;
+        this._priority = 0.0;
         this._isClipped = true;
         this._clippingPlanesState = 0; // encapsulates (_isClipped, clippingPlanes.enabled) and number/function
 
@@ -467,13 +452,13 @@ define([
          */
         contentAvailable : {
             get : function() {
-                return this.contentReady || (defined(this._expiredContent) && this._contentState !== Cesium3DTileContentState.FAILED);
+                return (this.contentReady && !this.hasEmptyContent && !this.hasTilesetContent) || (defined(this._expiredContent) && !this.contentFailed);
             }
         },
 
         /**
-         * Determines if the tile is ready to render. <code>true</code> if the tile
-         * is ready to render; otherwise, <code>false</code>.
+         * Determines if the tile's content is ready. This is automatically <code>true</code> for
+         * tile's with empty content.
          *
          * @memberof Cesium3DTile.prototype
          *
@@ -522,6 +507,23 @@ define([
             }
         },
 
+        /**
+         * Determines if the tile's content failed to load.  <code>true</code> if the tile's
+         * content failed to load; otherwise, <code>false</code>.
+         *
+         * @memberof Cesium3DTile.prototype
+         *
+         * @type {Boolean}
+         * @readonly
+         *
+         * @private
+         */
+        contentFailed : {
+            get : function() {
+                return this._contentState === Cesium3DTileContentState.FAILED;
+            }
+        },
+
         /**
          * Gets the promise that will be resolved when the tile's content is ready to process.
          * This happens after the content is downloaded but before the content is ready
@@ -618,7 +620,7 @@ define([
 
     function createPriorityFunction(tile) {
         return function() {
-            return tile._distanceToCamera;
+            return tile._priority;
         };
     }
 
@@ -690,7 +692,6 @@ define([
 
             if (defined(contentFactory)) {
                 content = contentFactory(tileset, that, that._contentResource, arrayBuffer, 0);
-                that.hasRenderableContent = true;
             } else {
                 // The content may be json instead
                 content = Cesium3DTileContentFactory.json(tileset, that, that._contentResource, arrayBuffer, 0);
@@ -710,7 +711,7 @@ define([
                 updateExpireDate(that);
 
                 // Refresh style for expired content
-                that.lastStyleTime = 0;
+                that._selectedFrame = 0;
 
                 that._contentState = Cesium3DTileContentState.READY;
                 that._contentReadyPromise.resolve(content);
@@ -735,7 +736,7 @@ define([
      * @private
      */
     Cesium3DTile.prototype.unloadContent = function() {
-        if (!this.hasRenderableContent) {
+        if (this.hasEmptyContent || this.hasTilesetContent) {
             return;
         }
 
@@ -744,8 +745,6 @@ define([
         this._contentReadyToProcessPromise = undefined;
         this._contentReadyPromise = undefined;
 
-        this.replacementNode = undefined;
-
         this.lastStyleTime = 0;
         this.clippingPlanesDirty = (this._clippingPlanesState === 0);
         this._clippingPlanesState = 0;
@@ -859,7 +858,7 @@ define([
      * Computes the distance from the center of the tile's bounding volume to the camera.
      *
      * @param {FrameState} frameState The frame state.
-     * @returns {Number} The distance, in meters, or zero if the camera is inside the bounding volume.
+     * @returns {Number} The distance, in meters.
      *
      * @private
      */
@@ -1032,14 +1031,24 @@ define([
 
     function applyDebugSettings(tile, tileset, frameState) {
         var hasContentBoundingVolume = defined(tile._header.content) && defined(tile._header.content.boundingVolume);
+        var empty = tile.hasEmptyContent || tile.hasTilesetContent;
 
         var showVolume = tileset.debugShowBoundingVolume || (tileset.debugShowContentBoundingVolume && !hasContentBoundingVolume);
         if (showVolume) {
+            var color;
+            if (!tile._finalResolution) {
+                color = Color.YELLOW;
+            } else if (empty) {
+                color = Color.DARKGRAY;
+            } else {
+                color = Color.WHITE;
+            }
             if (!defined(tile._debugBoundingVolume)) {
-                var color = tile._finalResolution ? (hasContentBoundingVolume ? Color.WHITE : Color.RED) : Color.YELLOW;
                 tile._debugBoundingVolume = tile._boundingVolume.createDebugVolume(color);
             }
             tile._debugBoundingVolume.update(frameState);
+            var attributes = tile._debugBoundingVolume.getGeometryInstanceAttributes('outline');
+            attributes.color = ColorGeometryInstanceAttribute.toValue(color, attributes.color);
         } else if (!showVolume && defined(tile._debugBoundingVolume)) {
             tile._debugBoundingVolume = tile._debugBoundingVolume.destroy();
         }

Source/Scene/Cesium3DTileBatchTable.js

@@ -1241,10 +1241,11 @@ define([
         OPAQUE_AND_TRANSLUCENT : 2
     };
 
-    Cesium3DTileBatchTable.prototype.addDerivedCommands = function(frameState, commandStart, finalResolution) {
+    Cesium3DTileBatchTable.prototype.addDerivedCommands = function(frameState, commandStart) {
         var commandList = frameState.commandList;
         var commandEnd = commandList.length;
         var tile = this._content._tile;
+        var finalResolution = tile._finalResolution;
         var tileset = tile._tileset;
         var bivariateVisibilityTest = tileset._skipLevelOfDetail && tileset._hasMixedContent && frameState.context.stencilBuffer;
         var styleCommandsNeeded = getStyleCommandsNeeded(this);
@@ -1276,9 +1277,8 @@ define([
                     }
                     tileset._backfaceCommands.push(derivedCommands.zback);
                 }
-                if (!defined(derivedCommands.stencil) || tile._selectionDepth !== tile._lastSelectionDepth) {
+                if (!defined(derivedCommands.stencil) || tile._selectionDepth !== getLastSelectionDepth(derivedCommands.stencil)) {
                     derivedCommands.stencil = deriveStencilCommand(derivedCommands.originalCommand, tile._selectionDepth);
-                    tile._lastSelectionDepth = tile._selectionDepth;
                 }
                 updateDerivedCommand(derivedCommands.stencil, command);
             }
@@ -1423,6 +1423,10 @@ define([
         return derivedCommand;
     }
 
+    function getLastSelectionDepth(stencilCommand) {
+        return stencilCommand.renderState.stencilTest.reference >>> 4;
+    }
+
     function getTranslucentRenderState(renderState) {
         var rs = clone(renderState, true);
         rs.cull.enabled = false;

Source/Scene/Cesium3DTileStyleEngine.js

@@ -65,7 +65,7 @@ define([
         var length = tiles.length;
         for (var i = 0; i < length; ++i) {
             var tile = tiles[i];
-            if (tile.selected && (tile.lastStyleTime !== lastStyleTime)) {
+            if (tile.lastStyleTime !== lastStyleTime) {
                 // Apply the style to this tile if it wasn't already applied because:
                 //   1) the user assigned a new style to the tileset
                 //   2) this tile is now visible, but it wasn't visible when the style was first assigned