change to xref

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

@@ -467,7 +467,7 @@ You can make Spatials that are not dynamic: Switch the RigidBodyControl to setKi
 *  A kinematic RigidBody has a mass.
 *  A kinematic can be moved and can exert forces on dynamic RigidBodys. This means you can use a kinematic node as a billiard cue or a remote-controlled battering ram.
 
-Learn more about static versus kinematic versus dynamic in the <<jme3/advanced/physics#,advanced physics doc>>.
+Learn more about static versus kinematic versus dynamic in the xref:ROOT:jme3/advanced/physics[advanced physics doc].
 
 
 == Excercises
@@ -508,10 +508,10 @@ Using physics everywhere in a game sounds like a cool idea, but it is easily ove
 
 == Conclusion
 
-You have learned how to activate the jBullet PhysicsSpace in an application by adding a `BulletAppState`. You have created PhysicsControls for simple Shape-based Geometries (for more complex shapes, read up on <<jme3/advanced/physics#,CollisionShapes>>). You have learned that physical objects are not only attached to the rootNode, but also registered to the PhysicsSpace. You know that it makes a difference whether a physical object has a mass (dynamic) or not (static). You are aware that overusing physics has a huge performance impact.
+You have learned how to activate the jBullet PhysicsSpace in an application by adding a `BulletAppState`. You have created PhysicsControls for simple Shape-based Geometries (for more complex shapes, read up on xref:ROOT:jme3/advanced/physics.adoc[CollisionShapes]). You have learned that physical objects are not only attached to the rootNode, but also registered to the PhysicsSpace. You know that it makes a difference whether a physical object has a mass (dynamic) or not (static). You are aware that overusing physics has a huge performance impact.
 
 
 [TIP]
 ====
-Congratulations! – You have completed the last beginner tutorial. Now you are ready to start <<jme3#,combining what you have learned>>, to create a cool 3D game of your own. Show us what you can do, and feel free to share your demos, game videos, and screenshots on the link:http://hub.jmonkeyengine.org/c/user-code-projects[User Code &amp; Projects Forum]!
+Congratulations! – You have completed the last beginner tutorial. Now you are ready to start xref:ROOT:jme3.adoc[combining what you have learned], to create a cool 3D game of your own. Show us what you can do, and feel free to share your demos, game videos, and screenshots on the link:http://hub.jmonkeyengine.org/c/user-code-projects[User Code &amp; Projects Forum]!
 ====