jriegel wrote:Where to place the origin is a decision we have to make. The only premises I would set are:
1) Usage of an right handed coordinate system (as everywhere in FreeCAD).
2) And using a clear length unit (e.g. mm or inch NOT px pixel). Where a CAD system after all....
1. On a sheet of paper i can invert the z axis to make the CS right handed
2. This is pretty hard. Please, under no circumstaces use CSS (relative) units in SVG. There is a single way to set redefine the user units (px) (the viewBOX). Everything else is derived from this definition of px. Do nerver ever put a unit statement inside a SVG besides for giving the real word size of the viewBox. I wrote the unit handling for SVG importer for FreeCAD and had to implement the crappy unit handling. It's based on CSS, it is ment to preserve relations when scaling something on a screen.
Please als well do not nest <SVG> Tags. It's allowed, but will cascade all the transformations.
The other [than px] absolute unit identifiers from CSS (i.e., pt, pc, cm, mm, in) are all defined as an appropriate multiple of one px
IMHO using one big translate operation to flip the y axis is the right way to go.