Make intersection behavior required, per resolution. Fixes https://www.w3.org/Bugs/Public/show_bug.cgi?id=15784.

Other minor wording changes.

Author: smfr

css3-transforms/ChangeLog

@@ -1,3 +1,7 @@
+2012-03-06 simon.fraser@apple.com
+    Make intersection behavior required, per resolution. Fixes https://www.w3.org/Bugs/Public/show_bug.cgi?id=15784.
+    Other minor wording changes.
+
 2012-03-06 simon.fraser@apple.com
     Remove the term 'depth' from the perspective() definition: https://www.w3.org/Bugs/Public/show_bug.cgi?id=15782
 

css3-transforms/Overview.html

@@ -879,15 +879,12 @@ <h3 id=transform-3d-rendering><span class=secno>5.1. </span>3D Transform
     height=200 src="examples/3d-rendering-context-3d.png" width=240></div>
   </div>
 
-  <div class=issue>
-   <p class=desc>Should intersection behavior be normative?</p>
-  </div>
-
   <p> Elements in the same <a class=term href="#d-rendering-context">3D
-   rendering context</a> may intersect with each other. User agents should
-   subdivide the planes of intersecting elements as described by <a
+   rendering context</a> may intersect with each other. User agents must
+   render intersection bysubdividing the planes of intersecting elements as
+   described by <a
    href="http://en.wikipedia.org/wiki/Newell's_algorithm">Newell's
-   algorithm</a> to render intersection.
+   algorithm</a>.
 
   <p> Untransformed elements in a <a class=term
    href="#d-rendering-context">3D rendering context</a> render on the Z=0
@@ -944,9 +941,9 @@ <h3 id=transform-3d-rendering><span class=secno>5.1. </span>3D Transform
   <p> Using three-dimensional transforms, it's possible to transform an
    element such that its reverse side is towards the viewer. 3D-tranformed
    elements show the same content on both sides, so the reverse side looks
-   like a mirror-image of the front side (as if the element were painted onto
-   a sheet of glass). Normally, elements whose reverse side is towards the
-   viewer remain visible. However, the &lsquo;<a
+   like a mirror-image of the front side (as if the element were projected
+   onto a sheet of glass). Normally, elements whose reverse side is towards
+   the viewer remain visible. However, the &lsquo;<a
    href="#backface-visibility"><code class=css><code
    class=property>backface-visibility</code></code></a>&rsquo; property
    allows the author to make an element invisible when its reverse side is

css3-transforms/Transforms.src.html

@@ -545,13 +545,10 @@ <h3 id="transform-3d-rendering">3D Transform Rendering</h3>
                 </div>
               </div>
 
-              <div class="issue">
-                <p class="desc">Should intersection behavior be normative?</p>
-              </div>
               <p>
-                Elements in the same <span class="term">3D rendering context</span> may intersect with each other. User agents should
-                subdivide the planes of intersecting elements as described by
-                <a href="http://en.wikipedia.org/wiki/Newell's_algorithm">Newell's algorithm</a> to render intersection.
+                Elements in the same <span class="term">3D rendering context</span> may intersect with each other. User agents must
+                render intersection bysubdividing the planes of intersecting elements as described by
+                <a href="http://en.wikipedia.org/wiki/Newell's_algorithm">Newell's algorithm</a>.
               </p>
               <p>
                 Untransformed elements in a <span class="term">3D rendering context</span> render on the Z=0 plane, yet may still
@@ -607,7 +604,7 @@ <h3 id="transform-3d-rendering">3D Transform Rendering</h3>
               <p>
                 Using three-dimensional transforms, it's possible to transform an element such that its reverse side
                 is towards the viewer. 3D-tranformed elements show the same content on both sides, so the reverse side
-                looks like a mirror-image of the front side (as if the element were painted onto a sheet of glass).
+                looks like a mirror-image of the front side (as if the element were projected onto a sheet of glass).
                 Normally, elements whose reverse side is towards the viewer remain visible. However, the
                 '<code class="property">backface-visibility</code>' property allows the author to make an element invisible
                 when its reverse side is towards the viewer. This behavior is "live"; if an element with