use cross ref

docs/modules/tutorials/pages/beginner/hello_asset.adoc

@@ -14,7 +14,7 @@ image::beginner/beginner-assets-models.png[beginner-assets-models.png,320,250,al
 
 [TIP]
 ====
-<<sdk/sample_code#,Trouble finding the files to run this sample?>> To get the assets (3D models) used in this example, add the included `jME3-testdata.jar` to your classpath. In project created with the jMonkeyEngine SDK (recommended), simply right-click your project, choose "`Properties`", go to "`Libraries`", press "`Add Library`" and add the preconfigured "`jme3-test-data`" library.
+xref:ROOT:sdk/sample_code.adoc[Trouble finding the files to run this sample?] To get the assets (3D models) used in this example, add the included `jME3-testdata.jar` to your classpath. In project created with the jMonkeyEngine SDK (recommended), simply right-click your project, choose "`Properties`", go to "`Libraries`", press "`Add Library`" and add the preconfigured "`jme3-test-data`" library.
 ====
 
 
@@ -120,7 +120,7 @@ MyGame/...
 
 ----
 
-This is just a suggested best practice, and it's what you get by default when creating a new Java project in the jMokeyEngine <<sdk#,SDK>>. You can create an `assets` directory and technically name the subdirectories whatever you like.
+This is just a suggested best practice, and it's what you get by default when creating a new Java project in the jMokeyEngine xref:ROOT:sdk.adoc[SDK]. You can create an `assets` directory and technically name the subdirectories whatever you like.
 
 IMPORTANT: When you build your project for distribution, there will be no `assets` directory. Instead, you will generate an `assets.jar` file, located in the `dist/lib` folder of your project that will contain the sub-folders of the `assets` directory and all the assets in those folders.
 
@@ -145,7 +145,7 @@ rootNode.attachChild(wall);
 
 ----
 
-In this case, you <<jme3/beginner/hello_material#,create your own Material>> and apply it to a Geometry. You base Materials on default material descriptions (such as "`Unshaded.j3md`"), as shown in this example.
+In this case, you xref:ROOT:jme3/beginner/hello_material.adoc[create your own Material] and apply it to a Geometry. You base Materials on default material descriptions (such as "`Unshaded.j3md`"), as shown in this example.
 
 
 === Loading Text and Fonts
@@ -174,7 +174,7 @@ Clear existing text in the guiNode by detaching all its children.
 
 === Loading a Model
 
-Export your 3D model in a <<jme3/features#supported-external-file-types,Supported External File Type>> (.mesh.xml, .scene, .material, .skeleton.xml, .gltf) and place it in a subdirectory of `assets/Models/`. The following code sample goes into the `simpleInitApp()` method.
+Export your 3D model in a xref:ROOT:jme3/features#supported-external-file-types[Supported External File Type] (.mesh.xml, .scene, .material, .skeleton.xml, .gltf) and place it in a subdirectory of `assets/Models/`. The following code sample goes into the `simpleInitApp()` method.
 
 [source,java]
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