add clearAssets method to viewer

android/src/main/cpp/filament_android.cpp

@@ -194,5 +194,9 @@ extern "C" {
   void remove_asset(void* viewer, void* asset) {
     ((FilamentViewer*)viewer)->removeAsset((SceneAsset*)asset);
   }
+
+  void clear_assets(void* viewer) {
+    ((FilamentViewer*)viewer)->clearAssets();
+  }
   
 }

android/src/main/kotlin/app/polyvox/filament/FilamentInterop.kt

@@ -64,6 +64,8 @@ interface FilamentInterop : Library {
 
     fun remove_asset(viewer:Pointer, asset:Pointer);
 
+    fun clear_assets(viewer:Pointer);
+
     fun remove_skybox(viewer:Pointer);
 
     fun remove_ibl(viewer:Pointer);

android/src/main/kotlin/app/polyvox/filament/FilamentView.kt

@@ -331,6 +331,10 @@ PlatformView  {
               _lib.remove_asset(_viewer!!, Pointer(call.arguments as Long))
               result.success("OK");
             } 
+            "clearAssets" -> {
+              _lib.clear_assets(_viewer!!)
+              result.success("OK");
+            } 
             "playAnimation" -> {
               val args = call.arguments as ArrayList<Any?>
               _lib.play_animation(Pointer(args[0] as Long), args[1] as Int, args[2] as Boolean)