Hide public underscore functions

loaders/src/glTF/2.0/glTFLoader.ts

@@ -1150,7 +1150,7 @@ export class GLTFLoader implements IGLTFLoader {
     }
 
     /**
-     * Loads a glTF animation channel.
+     * @hidden Loads a glTF animation channel.
      * @param context The context when loading the asset
      * @param animationContext The context of the animation when loading the asset
      * @param animation The glTF animation property

loaders/src/glTF/2.0/glTFLoaderExtension.ts

@@ -105,7 +105,7 @@ export interface IGLTFLoaderExtension extends IGLTFBaseLoaderExtension, IDisposa
     loadAnimationAsync?(context: string, animation: IAnimation): Nullable<Promise<AnimationGroup>>;
 
     /**
-     * Define this method to modify the default behavior when loading skins.
+     * @hidden Define this method to modify the default behavior when loading skins.
      * @param context The context when loading the asset
      * @param node The glTF node property
      * @param skin The glTF skin property
@@ -114,7 +114,7 @@ export interface IGLTFLoaderExtension extends IGLTFBaseLoaderExtension, IDisposa
     _loadSkinAsync?(context: string, node: INode, skin: ISkin): Nullable<Promise<void>>;
 
     /**
-     * Define this method to modify the default behavior when loading uris.
+     * @hidden Define this method to modify the default behavior when loading uris.
      * @param context The context when loading the asset
      * @param property The glTF property associated with the uri
      * @param uri The uri to load