diff --git a/02/hello_world.frag b/02/hello_world.frag
index a402fdd..152960e 100644
--- a/02/hello_world.frag
+++ b/02/hello_world.frag
@@ -2,6 +2,8 @@
 precision mediump float;
 #endif
 
+uniform float u_time;
+
 void main() {
 	gl_FragColor = vec4(1.0,0.0,1.0,1.0);
 }
diff --git a/12/accretion.jpg b/12/accretion.jpg
index 4430fb3..24f594c 100644
Binary files a/12/accretion.jpg and b/12/accretion.jpg differ
diff --git a/13/holdsworth.jpg b/13/holdsworth.jpg
index b338567..0dc66d7 100644
Binary files a/13/holdsworth.jpg and b/13/holdsworth.jpg differ
diff --git a/appendix/02/README.md b/appendix/02/README.md
index c030b16..cff6a52 100644
--- a/appendix/02/README.md
+++ b/appendix/02/README.md
@@ -35,10 +35,16 @@ For parsing the Markdown chapters into Latex and then into a PDF file we will us
 
 In **MacOSX**:
 
-Download and Install [basictex & MacTeX-Additions](http://www.tug.org/mactex/morepackages.html) and then install [Pandoc](http://johnmacfarlane.net/pandoc/) and Python by:
+Download and Install [basictex & MacTeX-Additions] by:
 
 ```bash
-brew install pandoc python2.7
+brew cask install mactex-no-gui
+```
+
+and then install [Pandoc](http://johnmacfarlane.net/pandoc/), Python 2 & glslViewer by:
+
+```bash
+brew install pandoc python@2 glslviewer
 ```
 
 On **Raspberry Pi** (Raspbian):
diff --git a/src/parseBook.py b/src/parseBook.py
index eef5162..e993ce2 100644
--- a/src/parseBook.py
+++ b/src/parseBook.py
@@ -42,7 +42,7 @@ def injectShaderBlocks(_folder, _text):
             shaderImage = folder + "/tmp-" + shaderName + ".png"
             shaderCommand = "glslViewer " + shaderPath + " " + \
                             " ".join(shaderTexturePaths) + \
-                            " -s 0.5 -o " + shaderImage
+                            " -s 0.5 --headless -o " + shaderImage
             print shaderCommand
             returnCode = subprocess.call(shaderCommand, shell=True)
             rta += "![](" + shaderImage + ")\n"
@@ -83,9 +83,9 @@ for folder in folders:
 
 # Set up the appropriate options for the pandoc command
 inputOptions = chapters
-generalOptions = ["-N", "--smart", "--no-tex-ligatures", "--toc", "--standalone",
-                  "--preserve-tabs", "-V documentclass=scrbook", "-V papersize=a4", "-V links-as-note", "-S"]
-latexOptions = ["--latex-engine=" + latexEngine]
+generalOptions = ["-N", "--toc", "--standalone",
+                  "--preserve-tabs", "-V documentclass=scrbook", "-V papersize=a4", "-V links-as-note"]
+latexOptions = ["--pdf-engine=" + latexEngine]
 outputOptions = ["--output={0}".format(pdfBookPath)]
 pandocCommand = ["pandoc"] + outputOptions + \
     inputOptions + generalOptions + latexOptions