3d artist objects need clear and unified way to get/set 3d coordinate data

[WeatherGod]

Because get_offsets() need to remain 2-D based for draw(), a separate function is needed to get and set the 3d coordinate data. Currently, one would set the 2d offsets, and then use set_3d_properties() to set the 3rd dimension data, which is awkward.

Perhaps this is an opportunity to create a function in the base artist class strictly for raw coordinate data? get/set_offsets() would then be intended more for display/transform purposes but would often be the same as the new methods. Also, this would help clear up confusion where some artists have get/set_array(), get/set_data() and get/set_offsets() all for coordinate data. A unified method would be valuable for documentation purposes.

[WeatherGod]

This would be a great low-hanging fruit task for SciPy 2015 sprints

[pelson]

I agree that the doing of this is simple, but I don't think it is an easy thing todo unless we can be very specific about what is required (unless one of us were doing it, rather than a newcomer to the project).

[OceanWolf]

Hmm, by the description above, do I understand that we want to separate out the screen stuff from the axes stuff because we shouldn't assume them as identical...?

I would imagine we should make this generic for all coordinate systems, not just 3d, what do we do with polar axes coordinates, and basemap?