Coordinate system orientation for extrusion of custom shapes

[Regina Henschel <regina.henschel@libreoffice.org>]

Hi all,

the attributes 19.154 draw:extrusion-first-light-direction and 19.163 
draw:extrusion-second-light-direction use a 3D vector. How are the axes 
of the underlying coordinate system orientated?

Because these extruded shapes use the enhanced-path, I expect that 
positive x-values go right and positive y-values go down.
But how is the z-axis orientated?

MS Office seems to use for the similar solids in binary MS Office file 
formats and rtf file format a z-axis, which points to the observer. That 
means, that the coordinate system is a left-hand system.

What is the orientation in ODF?

Does someone know an application other than LibreOffice/AOO, that 
supports extrusion of custom shapes in ODF?

To test the light direction extrude a circle and rotate the solid by 90Â 
around x-axis. That turns the extruded faces so, that you can see, where 
the light produces the maximal brightness. From that you can conclude, 
whether a positive z-value is interpreted as being on side of the 
observer or on opposite side of the solid.

Kind regards,
Regina