fix link to previus and next post

src/docs/asciidoc/jme3/advanced/pbr_part2.adoc

@@ -1,6 +1,6 @@
 = Physically Based Rendering – Part Two
 
-<<jme3/advanced/pbr_part1#,In previous post>>, I explained what you had to know about Physically Based Rendering if you were an artist. If you’re a developer, and reading this article, you may have tried, or are planning  to implement your own PBR system. If you started to read some of the available literature, you’ve probably been struck by the math complexity of it, and by the lack of explanation of the big picture. You usually see articles that focus on specifics parts of the process, and don’t talk much about other parts as they are assumed easier. At some point you have to assemble all these parts, and I had a hard time figuring out how to do it in my readings. I guess it’s considered basic stuff for other authors, but I think it deserves its proper explanation.
+<<pbr_part1#,In previous post>>, I explained what you had to know about Physically Based Rendering if you were an artist. If you’re a developer, and reading this article, you may have tried, or are planning  to implement your own PBR system. If you started to read some of the available literature, you’ve probably been struck by the math complexity of it, and by the lack of explanation of the big picture. You usually see articles that focus on specifics parts of the process, and don’t talk much about other parts as they are assumed easier. At some point you have to assemble all these parts, and I had a hard time figuring out how to do it in my readings. I guess it’s considered basic stuff for other authors, but I think it deserves its proper explanation.
 
 I don’t pretend these articles will enlighten you to the point you are ready to implement your own system, but I hope they will give you solid basis and understanding to start reading the literature without saying “WTF?? on every line as I did.
 
@@ -150,7 +150,7 @@ I won’t go into the details of all the alternatives I just want to expose an o
 
 That sums up the whole process, but there is still much to explain. In next post I’ll make a focus on indirect lighting, as it’s the part that gave me the hardest time to wrap my head around. I’ll explain the Image Based Lighting technique used, and how you can compute diffuse and specular from an Environment Map.
 
-<<jme3/advanced/pbr_part3#,Next Post>> 
+<<pbr_part3#,Next Post>> 
  
 == Lexical :