Availability from bvh

CHANGES.md

@@ -3,13 +3,17 @@ Change Log
 
 ### 1.52 - 2018-12-03
 
+##### Breaking Changes :mega:
+* `TerrainProviders` that implement `availability` must now also implement the `loadTileDataAvailability` method.
+
 ##### Additions :tada:
 * Added functions to get the most detailed height of 3D Tiles on-screen or off-screen. [#7115](https://github.com/AnalyticalGraphicsInc/cesium/pull/7115)
     * Added `Scene.sampleHeightMostDetailed`, an asynchronous version of `Scene.sampleHeight` that uses the maximum level of detail for 3D Tiles.
     * Added `Scene.clampToHeightMostDetailed`, an asynchronous version of `Scene.clampToHeight` that uses the maximum level of detail for 3D Tiles.
 * Added support for high dynamic range rendering. It is enabled by default when supported, but can be disabled with `Scene.highDynamicRange`. [#7017](https://github.com/AnalyticalGraphicsInc/cesium/pull/7017)
 * Added `Scene.invertClassificationSupported` for checking if invert classification is supported.
 * Added `computeLineSegmentLineSegmentIntersection` to `Intersections2D`. [#7228](https://github.com/AnalyticalGraphicsInc/Cesium/pull/7228)
+* Added ability to load availability progressively from a quantized mesh extension instead of upfront. This will speed up load time and reduce memory usage. [#7196](https://github.com/AnalyticalGraphicsInc/cesium/pull/7196)
 * Added the ability to apply styles to 3D Tilesets that don't contain features. [#7255](https://github.com/AnalyticalGraphicsInc/Cesium/pull/7255)
 
 ##### Fixes :wrench:

Source/Core/EllipsoidTerrainProvider.js

@@ -189,5 +189,17 @@ define([
         return undefined;
     };
 
+    /**
+     * Makes sure we load availability data for a tile
+     *
+     * @param {Number} x The X coordinate of the tile for which to request geometry.
+     * @param {Number} y The Y coordinate of the tile for which to request geometry.
+     * @param {Number} level The level of the tile for which to request geometry.
+     * @returns {undefined|Promise} Undefined if nothing need to be loaded or a Promise that resolves when all required tiles are loaded
+     */
+    EllipsoidTerrainProvider.prototype.loadTileDataAvailability = function(x, y, level) {
+        return undefined;
+    };
+
     return EllipsoidTerrainProvider;
 });

Source/Core/GoogleEarthEnterpriseTerrainProvider.js

@@ -580,6 +580,18 @@ define([
         return false;
     };
 
+    /**
+     * Makes sure we load availability data for a tile
+     *
+     * @param {Number} x The X coordinate of the tile for which to request geometry.
+     * @param {Number} y The Y coordinate of the tile for which to request geometry.
+     * @param {Number} level The level of the tile for which to request geometry.
+     * @returns {undefined|Promise} Undefined if nothing need to be loaded or a Promise that resolves when all required tiles are loaded
+     */
+    GoogleEarthEnterpriseTerrainProvider.prototype.loadTileDataAvailability = function(x, y, level) {
+        return undefined;
+    };
+
     //
     // Functions to handle imagery packets
     //

Source/Core/TerrainProvider.js

@@ -227,5 +227,15 @@ define([
      */
     TerrainProvider.prototype.getTileDataAvailable = DeveloperError.throwInstantiationError;
 
+    /**
+     * Makes sure we load availability data for a tile
+     *
+     * @param {Number} x The X coordinate of the tile for which to request geometry.
+     * @param {Number} y The Y coordinate of the tile for which to request geometry.
+     * @param {Number} level The level of the tile for which to request geometry.
+     * @returns {undefined|Promise} Undefined if nothing need to be loaded or a Promise that resolves when all required tiles are loaded
+     */
+    TerrainProvider.prototype.loadTileDataAvailability = DeveloperError.throwInstantiationError;
+
     return TerrainProvider;
 });

Source/Core/VRTheWorldTerrainProvider.js

@@ -355,5 +355,17 @@ define([
         return undefined;
     };
 
+    /**
+     * Makes sure we load availability data for a tile
+     *
+     * @param {Number} x The X coordinate of the tile for which to request geometry.
+     * @param {Number} y The Y coordinate of the tile for which to request geometry.
+     * @param {Number} level The level of the tile for which to request geometry.
+     * @returns {undefined|Promise} Undefined if nothing need to be loaded or a Promise that resolves when all required tiles are loaded
+     */
+    VRTheWorldTerrainProvider.prototype.loadTileDataAvailability = function(x, y, level) {
+        return undefined;
+    };
+
     return VRTheWorldTerrainProvider;
 });

Source/Core/sampleTerrainMostDetailed.js

@@ -1,15 +1,19 @@
 define([
         '../ThirdParty/when',
+        './Cartesian2',
         './defined',
         './DeveloperError',
         './sampleTerrain'
     ], function(
         when,
+        Cartesian2,
         defined,
         DeveloperError,
         sampleTerrain) {
     'use strict';
 
+    var scratchCartesian2 = new Cartesian2();
+
     /**
      * Initiates a sampleTerrain() request at the maximum available tile level for a terrain dataset.
      *
@@ -43,36 +47,70 @@ define([
         }
         //>>includeEnd('debug');
 
-        return terrainProvider.readyPromise.then(function() {
-            var byLevel = [];
+        return terrainProvider.readyPromise
+            .then(function() {
+                var byLevel = [];
+                var maxLevels = [];
 
-            var availability = terrainProvider.availability;
+                var availability = terrainProvider.availability;
 
-            //>>includeStart('debug', pragmas.debug);
-            if (!defined(availability)) {
-                throw new DeveloperError('sampleTerrainMostDetailed requires a terrain provider that has tile availability.');
-            }
-            //>>includeEnd('debug');
+                //>>includeStart('debug', pragmas.debug);
+                if (!defined(availability)) {
+                    throw new DeveloperError('sampleTerrainMostDetailed requires a terrain provider that has tile availability.');
+                }
+                //>>includeEnd('debug');
 
-            for (var i = 0; i < positions.length; ++i) {
-                var position = positions[i];
-                var maxLevel = availability.computeMaximumLevelAtPosition(position);
+                var promises = [];
+                for (var i = 0; i < positions.length; ++i) {
+                    var position = positions[i];
+                    var maxLevel = availability.computeMaximumLevelAtPosition(position);
+                    maxLevels[i] = maxLevel;
+                    if (maxLevel === 0) {
+                        // This is a special case where we have a parent terrain and we are requesting
+                        // heights from an area that isn't covered by the top level terrain at all.
+                        // This will essentially trigger the loading of the parent terrains root tile
+                        terrainProvider.tilingScheme.positionToTileXY(position, 1, scratchCartesian2);
+                        var promise = terrainProvider.loadTileDataAvailability(scratchCartesian2.x, scratchCartesian2.y, 1);
+                        if (defined(promise)) {
+                            promises.push(promise);
+                        }
+                    }
 
-                var atLevel = byLevel[maxLevel];
-                if (!defined(atLevel)) {
-                    byLevel[maxLevel] = atLevel = [];
+                    var atLevel = byLevel[maxLevel];
+                    if (!defined(atLevel)) {
+                        byLevel[maxLevel] = atLevel = [];
+                    }
+                    atLevel.push(position);
                 }
-                atLevel.push(position);
-            }
 
-            return when.all(byLevel.map(function(positionsAtLevel, index) {
-                if (defined(positionsAtLevel)) {
-                    return sampleTerrain(terrainProvider, index, positionsAtLevel);
-                }
-            })).then(function() {
-                return positions;
+                return when.all(promises)
+                    .then(function() {
+                        return when.all(byLevel.map(function(positionsAtLevel, index) {
+                            if (defined(positionsAtLevel)) {
+                                return sampleTerrain(terrainProvider, index, positionsAtLevel);
+                            }
+                        }));
+                    })
+                    .then(function() {
+                        var changedPositions = [];
+                        for (var i = 0; i < positions.length; ++i) {
+                            var position = positions[i];
+                            var maxLevel = availability.computeMaximumLevelAtPosition(position);
+
+                            if (maxLevel !== maxLevels[i]) {
+                                // Now that we loaded the max availability, a higher level has become available
+                                changedPositions.push(position);
+                            }
+                        }
+
+                        if (changedPositions.length > 0) {
+                            return sampleTerrainMostDetailed(terrainProvider, changedPositions);
+                        }
+                    })
+                    .then(function() {
+                        return positions;
+                    });
             });
-        });
     }
 
     return sampleTerrainMostDetailed;

Specs/Core/CesiumTerrainProviderSpec.js

@@ -89,6 +89,10 @@ defineSuite([
         };
     }
 
+    function returnMetadataAvailabilityTileJson() {
+        return returnTileJson('Data/CesiumTerrainTileJson/MetadataAvailability.tile.json');
+    }
+
     function waitForTile(level, x, y, requestNormals, requestWaterMask, f) {
         var terrainProvider = new CesiumTerrainProvider({
             url : 'made/up/url',
@@ -652,6 +656,33 @@ defineSuite([
             });
         });
 
+        it('provides QuantizedMeshTerrainData with Metadata availability', function() {
+            Resource._Implementations.loadWithXhr = function(url, responseType, method, data, headers, deferred, overrideMimeType) {
+                Resource._DefaultImplementations.loadWithXhr('Data/CesiumTerrainTileJson/tile.metadataavailability.terrain', responseType, method, data, headers, deferred);
+            };
+
+            returnMetadataAvailabilityTileJson();
+
+            var terrainProvider = new CesiumTerrainProvider({
+                url : 'made/up/url'
+            });
+
+            return pollToPromise(function() {
+                return terrainProvider.ready;
+            }).then(function() {
+                expect(terrainProvider.hasMetadata).toBe(true);
+                expect(terrainProvider._layers[0].availabilityLevels).toBe(10);
+                expect(terrainProvider.availability.isTileAvailable(0,0,0)).toBe(true);
+                expect(terrainProvider.availability.isTileAvailable(0,1,0)).toBe(true);
+                expect(terrainProvider.availability.isTileAvailable(1,0,0)).toBe(false);
+
+                return terrainProvider.requestTileGeometry(0, 0, 0);
+            }).then(function(loadedData) {
+                expect(loadedData).toBeInstanceOf(QuantizedMeshTerrainData);
+                expect(terrainProvider.availability.isTileAvailable(1,0,0)).toBe(true);
+            });
+        });
+
         it('returns undefined if too many requests are already in progress', function() {
             var baseUrl = 'made/up/url';
 
@@ -726,6 +757,29 @@ defineSuite([
             });
         });
 
+        it('getTileDataAvailable() with Metadata availability', function() {
+            Resource._Implementations.loadWithXhr = function(url, responseType, method, data, headers, deferred, overrideMimeType) {
+                Resource._DefaultImplementations.loadWithXhr('Data/CesiumTerrainTileJson/tile.metadataavailability.terrain', responseType, method, data, headers, deferred);
+            };
+
+            returnMetadataAvailabilityTileJson();
+
+            var terrainProvider = new CesiumTerrainProvider({
+                url : 'made/up/url'
+            });
+
+            return pollToPromise(function() {
+                return terrainProvider.ready;
+            }).then(function() {
+                expect(terrainProvider.getTileDataAvailable(0,0,0)).toBe(true);
+                expect(terrainProvider.getTileDataAvailable(0,0,1)).toBeUndefined();
+
+                return terrainProvider.requestTileGeometry(0, 0, 0);
+            }).then(function() {
+                expect(terrainProvider.getTileDataAvailable(0,0,1)).toBe(true);
+            });
+        });
+
         it('supports a query string in the base URL', function() {
             Resource._Implementations.loadWithXhr = function(url, responseType, method, data, headers, deferred, overrideMimeType) {
                 // Just return any old file, as long as its big enough

Specs/Data/CesiumTerrainTileJson/MetadataAvailability.tile.json

@@ -0,0 +1 @@
+{"attribution":"","bounds":[-180,-90,180,90],"bvhlevels":6,"description":"","extensions":["bvh","metadata","octvertexnormals"],"format":"quantized-mesh-1.0","maxzoom":8,"metadataAvailability":10,"minzoom":0,"name":"","projection":"EPSG:4326","scheme":"tms","tiles":["{z}/{x}/{y}.terrain?v={version}"],"version":"1.33.0"}