diff --git a/csg.js b/csg.js
index e07488d..01c1be1 100644
--- a/csg.js
+++ b/csg.js
@@ -1062,10 +1062,8 @@ CSG.roundedCube = function(options) {
   var resolution = CSG.parseOptionAsFloat(options, "resolution", 8);
   if(resolution < 4) resolution = 4;
   var roundradius = CSG.parseOptionAsFloat(options, "roundradius", 0.2);
-  var innercuberadius=cuberadius.clone();
-  innercuberadius.x -= roundradius;
-  innercuberadius.y -= roundradius;
-  innercuberadius.z -= roundradius;
+  var innercuberadius=cuberadius;
+  innercuberadius = innercuberadius.minus(new CSG.Vector3D(roundradius));
   var result = CSG.cube({center: center, radius: [cuberadius.x, innercuberadius.y, innercuberadius.z]});
   result = result.unionSub( CSG.cube({center: center, radius: [innercuberadius.x, cuberadius.y, innercuberadius.z]}),false,false);
   result = result.unionSub( CSG.cube({center: center, radius: [innercuberadius.x, innercuberadius.y, cuberadius.z]}),false,false);
@@ -2213,7 +2211,7 @@ CSG.Node = function(parent) {
 CSG.Node.prototype = {
   // Convert solid space to empty space and empty space to solid space.
   invert: function() {
-    this.plane = this.plane.flipped();
+    if (this.plane) this.plane = this.plane.flipped();
     if (this.front) this.front.invert();
     if (this.back) this.back.invert();
     var temp = this.front;
diff --git a/index.html b/index.html
index e76d696..66ede79 100644
--- a/index.html
+++ b/index.html
@@ -590,7 +590,9 @@ view the source of csg.js:
 var vec1 = new CSG.Vector3D(1,2,3);       // 3 arguments
 var vec2 = new CSG.Vector3D( [1,2,3] );   // 1 array argument
 var vec3 = new CSG.Vector3D(vec2);        // cloning a vector
+// get the values as: vec1.x, vec.y, vec1.z
 // vector math. All operations return a new vector, the original is unmodified!
+// vectors cannot be modified. Instead you should create a new vector.
 vec.negated()
 vec.abs()
 vec.plus(othervector)
@@ -607,6 +609,8 @@ vec.distanceTo(othervector)
 vec.distanceToSquared(othervector)  // == vec.distanceTo(othervector)^2
 vec.equals(othervector)
 vec.multiply4x4(matrix4x4)   // right multiply by a 4x4 matrix
+vec.min(othervector)        // returns a new vector with the minimum x,y and z values
+vec.max(othervector)        // returns a new vector with the maximum x,y and z values
 
 // --------- Vector2D ---------------------
 var vec1 = new CSG.Vector2D(1,2);       // 2 arguments
diff --git a/processfile.html b/processfile.html
index bfca818..3809a56 100644
--- a/processfile.html
+++ b/processfile.html
@@ -199,7 +199,13 @@ Then press the Debug button above. The debugger will stop just before executing
 <br><br>
 For more information about debugging in Chrome see 
 <a href="http://code.google.com/chrome/devtools/docs/overview.html" target="_blank">Chrome Developer Tools: Overview</a>
-
+<br><br>
+You can output log messages from your script using:
+<pre>
+OpenJsCad.log("Hello");
+</pre>
+The log messages will appear in the browser's console (shown using Ctrl+Shift+I in Chrome). They will appear
+even while not actually debugging.
 <br><br>
 
 </body>