Re: [office] OFFICE-3928 - 3D charts

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

Hello members,

next try to put the 3D cases in a text (the first paragraph is the 
existing text). But I'm not sure, read end of the mail.

11.5 3D Plot Area
The plot area may be displayed as a 3D scene as specified in section 
10.5.2. All 3D attributes that can be applied to the <dr3d:scene> 
element can be applied to the <chart:plot-area> element. This includes 
the dr3d:transform attribute that specifies the rotation of the 
three-dimensional plot area. 10.5.2 The <chart:plot-area> element may 
contain a <dr3d:light> element as specified in section 10.5.3.

The svg:x, svg:y, svg:width and svg:height attributes specify together a 
rectangular viewport. Producers shall use uniform scaling to center the 
projection of the scene maximally inside the viewport.

If the <chart:plot-area> element contains a <chart:coordinate-region> 
element, the position and size values of the <chart:coordinate-region> 
element are used instead of those from the <chart:plot-area>. In 
calculations in regard to position and size of the projection of the 3D 
scene these parts are used:
For types chart:circle and chart:ring the content as described in 11.x 
is extruded and the bounding cuboid is used.
For types, where axes are present the cuboid generated by the used 
intervals on the axes is used.


Th proposal above contains uniform scaling as it is done in LibreOffice. 
But in OOXML it is possible to use different scaling factors for width 
and height, done by checkbox "Autoscale" and fields Depth and Height in 
the tool 3D-Rotation in the UI of Excel, and in file format "21.2.2.83 
hPercent (Height Percent)" and "21.2.2.41 depthPercent (Depth Percent)". 
So for better interoperability it might be useful not to demand uniform 
scaling, or at least limit it to the predefined types.

Kind regards
Regina