[QGIS-Developer] QGIS 3D: Support for 3DM (x,y,z,m)

[Martin Dobias]

Hi Jakob

On Fri, Jan 5, 2018 at 3:31 PM, Jakob Lanstorp <jlanstorp at gmail.com> wrote:
>>>M values are ignored as their meaning is application specific. How
>>>would you like to use M values in the 3D view?
>
> M values is not for rendering in 3D, but just residing as part of my
> existing 4D data. When the M value is present the Z value is reset to 0 -
> and not rendered correct. Right now I would have to strip the M value from
> my data before rendering in the QGIS 3D map.

Looks like you have found a bug in postgres provider - I have filed it
here: https://issues.qgis.org/issues/17814


> It could actually be useful rendering the M value as a label in the 3D map.
> It could be age or velocity of a particle in groundwater particle flowmodel.

Indeed - support for labels in 3D view would be nice to have. The kind
of labels like place names in Google Earth where they are always
facing the camera and their size does not change as the camera moves.


> You 3D terrain model work with 2D draping works just fine. As I stated in
> the qgis issue log - having rendering of negative Z values could be fine for
> subsurface data.

There are already people interested in working with subsurface data in
the 3D view, so hopefully we will get some improvements in that
direction in the following releases.

Cheers
Martin