[QGIS-Developer] 3D View Interface Usability

[Jed Frechette]

Happy New Year to all,

Recently I’ve been spending time playing with the 3D view in QGIS and
I’m hoping to start a discussion about the UI and whether or not it
might make sense to consider some changes to that UI based on what the
intended uses of the 3D view are.

Since I haven’t been directly involved in QGIS development before I’m
approaching this from a user’s perspective and thought I should start
with my observations and assumptions in case they’re radically
off-base compared to what the core developers envision for the 3D
view.

Looking at the current state of the 3D view it seems heavily
influenced by Google Earth. In particular, it seems to be primarily
designed to simply display content that was created elsewhere. In the
context of the rest of the QGIS UI, it is much more similar to the
Print Layout view than the main 2D Map view. From a workflow
perspective, you work with your data in the main 2D Map and then
switch to the Print Layout or 3D views when you want to render that
data in a different context.

I think now is a good time to start thinking about a potentially
bigger role for the 3D view because of the upcoming point cloud
support. I know that interactive tools are out of scope for the
current point cloud project, however, I think as soon as users can
visualize point clouds in QGIS they will want to start interacting
with them. Once the novelty wears off, simply rendering a point cloud
in 3D is pretty ugly and not terribly useful. However, being able to
digitize 3D points or lines with snapping to that point cloud is
extremely useful and that type of work will be difficult to do without
a well-designed 3D viewport.

Even without new interactive tools, I think the more volumetric and
often unevenly distributed nature of most point cloud datasets will
make the current Google Earth style navigation less intuitive than it
is when dealing with the mostly 2D data it was designed to interact
with. For example, with the current camera controls you can’t track
along the world z-axis so you lose a degree of freedom when the camera
is horizontal. If you are looking at a street level building facade
and want to move to looking at the 20th floor you can’t just track
along the z-axis to get there. You need to tilt the camera up, try to
place it’s rotation point at the 20th floor (possibly moving the
camera backward and hoping nothing blocks your view), then tilt the
camera down (which translates the camera up) to get back to
horizontal.

Although I spend a fair amount of time doing GIS work, my perspective
comes from spending the last 10 years working with lidar and similar
data in 3D modeling and metrology applications, where the primary mode
of interaction is a 3D viewport. As a result, I have several specific
thoughts on changes to the 3D View’s UI that would make it easier to
use, better able to eventually support more interactive tools and more
consistent with the rest of the QGIS UI. This email is already long
enough though so rather than get into that now, I’d first rather ask
what others think of the current 3D view.

How much do people currently use the 3D view? Is the current UI
working well for how it is being used? What about down the road? Is
there a desire for more 3D tools and if so are there limitations of
the current design that should be reconsidered?

Thanks for reading,

-- 
Jed Frechette