fix(examples): add envmap for PBR materials in 3d tiles loader example

examples/3dtiles_loader.html

@@ -57,8 +57,12 @@
         </script>
 
         <script type="module">
-            import { AmbientLight } from 'three';
+            import {
+                AmbientLight,
+                PMREMGenerator,
+            } from 'three';
             import { MeshoptDecoder } from 'three/addons/libs/meshopt_decoder.module.js';
+            import { RoomEnvironment } from 'three/addons/environments/RoomEnvironment.js';
             import {
                 zoomToLayer,
                 fillHTMLWithPickingInfo,
@@ -106,6 +110,13 @@
             const light = new AmbientLight(0x404040, 40);
             view.scene.add(light);
 
+            // Set the environment map for all physical materials in the scene.
+            // Otherwise, mesh with only diffuse colors will appear black.
+            const environment = new RoomEnvironment();
+            const pmremGenerator = new PMREMGenerator(view.renderer);
+            view.scene.environment = pmremGenerator.fromScene(environment).texture;
+            pmremGenerator.dispose();
+
             // Setup loading screen
             setupLoadingScreen(viewerDiv, view);