rename setLayerEnabled to setLayerVisibility, add setVisibilityLayer method

thermion_dart/lib/thermion_dart/viewer/ffi/thermion_dart.g.dart

@@ -1155,10 +1155,18 @@ external void get_bounding_box_to_out(
 
 @ffi.Native<ffi.Void Function(ffi.Pointer<ffi.Void>, ffi.Int, ffi.Bool)>(
     isLeaf: true)
-external void set_layer_enabled(
+external void set_layer_visibility(
   ffi.Pointer<ffi.Void> sceneManager,
   int layer,
-  bool enabled,
+  bool visible,
+);
+
+@ffi.Native<ffi.Void Function(ffi.Pointer<ffi.Void>, EntityId, ffi.Int)>(
+    isLeaf: true)
+external void set_visibility_layer(
+  ffi.Pointer<ffi.Void> sceneManager,
+  int entity,
+  int layer,
 );
 
 @ffi.Native<
@@ -1203,6 +1211,15 @@ external void remove_stencil_highlight(
   int entity,
 );
 
+@ffi.Native<
+    ffi.Pointer<TMaterialInstance> Function(
+        ffi.Pointer<ffi.Void>, EntityId, ffi.Int)>(isLeaf: true)
+external ffi.Pointer<TMaterialInstance> get_material_instance_at(
+  ffi.Pointer<ffi.Void> sceneManager,
+  int entity,
+  int materialIndex,
+);
+
 @ffi.Native<
     ffi.Void Function(ffi.Pointer<ffi.Void>, EntityId, ffi.Int,
         ffi.Pointer<ffi.Char>, ffi.Float)>(isLeaf: true)

thermion_dart/lib/thermion_dart/viewer/ffi/thermion_viewer_ffi.dart

@@ -1920,8 +1920,17 @@ class ThermionViewerFFI extends ThermionViewer {
   ///
   ///
   ///
-  Future setLayerEnabled(int layer, bool enabled) async {
-    set_layer_enabled(_sceneManager!, layer, enabled);
+  Future setLayerVisibility(int layer, bool visible) {
+    set_layer_visibility(_sceneManager!, layer, visible);
+    return Future.value();
+  }
+
+  ///
+  ///
+  ///
+  Future setVisibilityLayer(ThermionEntity entity, int layer) {
+    set_visibility_layer(_sceneManager!, entity, layer);
+    return Future.value();
   }
 
   ///

thermion_dart/lib/thermion_dart/viewer/thermion_viewer_base.dart

@@ -545,7 +545,7 @@ abstract class ThermionViewer {
   Future moveCameraToAsset(ThermionEntity entity);
 
   ///
-  /// Enables/disables frustum culling. Currently we don't expose a method for manipulating the camera projection/culling matrices so this is your only option to deal with unwanted near/far clipping.
+  /// Enables/disables frustum culling.
   ///
   Future setViewFrustumCulling(bool enabled);
 
@@ -596,14 +596,15 @@ abstract class ThermionViewer {
   /// Sets the material property [propertyName] under material [materialIndex] for [entity] to [value].
   /// [entity] must have a Renderable attached.
   ///
-  Future setMaterialPropertyInt(ThermionEntity entity, String propertyName,
-      int materialIndex, int value);
+  Future setMaterialPropertyInt(
+      ThermionEntity entity, String propertyName, int materialIndex, int value);
 
   ///
   /// Sets the depthWrite material instance at [materialIndex] for [entity] to [enabled].
   /// [entity] must have a Renderable attached.
   ///
-  Future setMaterialDepthWrite(ThermionEntity entity, int materialIndex, bool enabled);
+  Future setMaterialDepthWrite(
+      ThermionEntity entity, int materialIndex, bool enabled);
 
   ///
   /// Scale [entity] to fit within the unit cube.
@@ -853,7 +854,12 @@ abstract class ThermionViewer {
   /// We place all scene assets in layer 0 (enabled by default), gizmos in layer 1 (enabled by default), world grid in layer 2 (disabled by default).
   /// Use this method to toggle visibility of the respective layer.
   ///
-  Future setLayerEnabled(int layer, bool enabled);
+  Future setLayerVisibility(int layer, bool visible);
+
+  ///
+  /// Assigns [entity] to visibility layer [layer].
+  /// 
+  Future setVisibilityLayer(ThermionEntity entity, int layer);
 
   ///
   /// Show/hide the translation gizmo.