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by jasondavies 4606 days ago
Thanks for the feedback!

I agree it’s not the most intuitive approach for all situations, particularly when you’re used to a North-South orientation for maps. The rolling is perhaps made more obvious with my use of a graticule. For this reason, I’d be interested in optionally restricting to two degrees of freedom when dragging on the globe, and the third angle could be modified when dragging outside the globe only. So the point being dragged on the globe could still remain under the cursor where possible using this approach.

Interestingly, Google Earth uses the same approach as I do, though perhaps it seems less obvious without a graticule.

6 comments

I don't like Google Earth's approach too much either, I always have to correct back the roll..

I can understand it when you reach the zoom level of a city, at that point you correlate the data on the map with actual visual memories at the street level, where Up does not correspond to North anymore, but instead is related to Forward. Maybe an exponential transition between the two systems as you zoom in?

Interestingly, on a phone it is also trickier because there is not "grab" equivalent and the y axis also makes the page scroll.

Sorry, I don't want to sound overly critic :)

I'd like to disagree. I prefer the improved version.

One of the great joys of manipulating a globe like this is being able to rotate it into completely novel views: not just upside down but at totally arbitrary angles.

The improved version makes this very simple.

If you only want to view the world in a conventional (or upside down) way then I agree that the naive version is very easy to use,

I haven't tried this on a computer yet, just on the iPhone. So I can't address the above comments. But using touch, I think you have created the most intuitive 3-angle rotation I've used yet. The responsiveness is great, and the path follows my finger as I would expect it to (from a purely physical, action-reaction point of view). The mechanics of roll using a mouse are non-obvious to most people, and to have that interface issue addressed by this touch solution is an accomplishment. Maybe that's the real story here?
Struggled with that too. Decided to lock rotation to λ,φ only and rotate with alt key, since it's pretty uncommon.

I should consider revisiting my project from earlier this year and implementing the described approach with versors from your example to simulate plate movement.

http://mxfh.github.io/d3canvasglobes/

(right now the mouse mapping behaves quite odd with rotated views)

What might be cool is allowing the globe's roll to be locked but instead of being rigid, allow the user to affect the roll yet bounce back once they release.
The problem is, trackball-style movement is super useful when you get used to it. But is simply awfully unintuitive, and I'd probably never use it somewhere that not something like a professional tool.