SVG 3D transforms

             Hi,

     I'm authoring a JS library to stream SVG Path Datas ( 
https://github.com/nfroidure/SVGPathData) and i would like to implement 
SVG 3D transforms.

     When combining multiple SVG 3D transformations, should i keep the z 
coordinate value and pass it to other transformations or should i always 
consider that z value is 0?

     Related spec: 
http://www.w3.org/TR/SVG-Transforms/#threed-matrix-definition

     Thanks for your answers.

-- 
Cordialement, Nicolas Froidure, Elitwork