[x3d-public] [x3d] Use of containerField in V4+

[Don Brutzman]

On 12/15/2015 3:54 AM, Don Brutzman wrote:
> containerField describes a node's relationship to its parents.  The default values are typically not needed by authors or generators.
>
> Debate on this topic was a lengthy effort a long time ago. Wrapper tags only simplify rare occurrences,such as Collision node children, distinguishing between a 'proxy' Shape and 'children' Shape nodes.
>
> Extensive reasons against wrapper tags in the XML encoding can be found in
> http://www.web3d.org/x3d/content/examples/Basic/development/WrapperTagsConsideredHarmful.html
>
> As a result we have a much terser XML encoding with corresponding reductions in file size, transfer times and scene loading.

The example scene referred to in that page was moved and renamed when archived.  Updated links:

http://www.web3d.org/x3d/content/examples/Basic/development/WrapperTagsExampleWrapped.html
http://www.web3d.org/x3d/content/examples/Basic/development/WrapperTagsExampleUnwrapped.html

http://www.web3d.org/x3d/content/examples/Basic/development/#WrapperTagsExample

Reviewing  this example, it appears that the metrics are understated by half because only the open-element wrapper tags.  So instead of a scene with 34 node tags needing 35 wrapper tags, it would need 70 open+close wrapper tags added.

So use of wrapper tags triples the number of XML elements needed to express an X3D scene.  No thanks.

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman