3D Tiles style fixes

Source/Scene/Cesium3DTile.js

@@ -739,6 +739,7 @@ define([
 
                 // Refresh style for expired content
                 that._selectedFrame = 0;
+                that.lastStyleTime = 0;
 
                 that._contentState = Cesium3DTileContentState.READY;
                 that._contentReadyPromise.resolve(content);

Source/Scene/Cesium3DTilesetTraversal.js

@@ -137,9 +137,8 @@ define([
                 tileContent.featurePropertiesDirty = false;
                 tile.lastStyleTime = 0; // Force applying the style to this tile
                 tileset._selectedTilesToStyle.push(tile);
-            } else if ((tile._selectedFrame !== frameState.frameNumber - 1)) {
+            } else if ((tile._selectedFrame < frameState.frameNumber - 1)) {
                 // Tile is newly selected; it is selected this frame, but was not selected last frame.
-                tile.lastStyleTime = 0; // Force applying the style to this tile
                 tileset._selectedTilesToStyle.push(tile);
             }
             tile._selectedFrame = frameState.frameNumber;

Specs/Scene/Cesium3DTilesetSpec.js

@@ -1979,6 +1979,48 @@ defineSuite([
         });
     });
 
+    it('applies style when tile is selected after new style is applied', function() {
+        return Cesium3DTilesTester.loadTileset(scene, withBatchTableUrl).then(function(tileset) {
+            var feature = tileset.root.content.getFeature(0);
+            tileset.style = new Cesium3DTileStyle({color: 'color("red")'});
+            scene.renderForSpecs();
+            expect(feature.color).toEqual(Color.RED);
+
+            tileset.style = new Cesium3DTileStyle({color: 'color("blue")'});
+            scene.renderForSpecs();
+            expect(feature.color).toEqual(Color.BLUE);
+
+            viewNothing();
+            tileset.style = new Cesium3DTileStyle({color: 'color("lime")'});
+            scene.renderForSpecs();
+            expect(feature.color).toEqual(Color.BLUE); // Hasn't been selected yet
+
+            viewAllTiles();
+            scene.renderForSpecs();
+            expect(feature.color).toEqual(Color.LIME);
+
+            // Feature's show property is preserved if the style hasn't changed and the feature is newly selected
+            feature.show = false;
+            scene.renderForSpecs();
+            expect(feature.show).toBe(false);
+            viewNothing();
+            scene.renderForSpecs();
+            expect(feature.show).toBe(false);
+            viewAllTiles();
+            expect(feature.show).toBe(false);
+        });
+    });
+
+    it('does not reapply style during pick pass', function() {
+        return Cesium3DTilesTester.loadTileset(scene, withBatchTableUrl).then(function(tileset) {
+            tileset.style = new Cesium3DTileStyle({color: 'color("red")'});
+            scene.renderForSpecs();
+            expect(tileset.statistics.numberOfTilesStyled).toBe(1);
+            scene.pickForSpecs();
+            expect(tileset.statistics.numberOfTilesStyled).toBe(0);
+        });
+    });
+
     it('applies style with complex color expression to a tileset', function() {
         return Cesium3DTilesTester.loadTileset(scene, withBatchTableUrl).then(function(tileset) {
             // Each feature in the b3dm file has an id property from 0 to 9