Camera roll + free look interaction

[klokan]

Roll of the camera has been disabled in the initial implementation (#16) together with the free look user interaction which is setting the roll on camera internally. The user can't set the roll with the existing interaction on the globe.

Roll explained in illustration from #8:

(Update: the original image is in: http://data.webglearth.com/doc/webgl-earthch3.html#x4-240003.6 and embeded in #16)

The reason is that the alogorithm for synchronization of the 2d and 3d view will get more complicated, if roll is implemented, because roll is influencing also heading (=rotation in ol3) and this must be taken into account in the calculations. It is doable, just not yet done.

To introduce the roll and free look the olcs.Camera.prototype.updateView must be improved to ensure the 2D view and 3D view are properly synchronized.

The commit for disabling the roll and free look which should be reverted later: klokantech@f2b68b0
available also here: https://gist.github.com/klokan/99a3be6a193a71ac4157

[elemoine]

Thanks a lot for the drawing, that is very useful.

[klokan]

BTW It seems in Google Maps WebGL Globe the roll is also not available.
https://www.google.com/maps/@44.1798527,7.3205526,87149a,20y,8.57h,68.69t/data=!3m1!1e3

[elemoine]

Indeed, unless they use a modifier that we're not aware of.

[klokan]

The look towards the sky is not allowed there either - Google's answer to
what we have discussed yesterday on the kick-off meeting.

There is also a limit on latitude towards poles dynamically calculated
based on altitude - to prevent inertial dragging issue where you easily end
up on the pole - as visible at http://www.webglearth.com/ if you zoom out
and drag the small globe to the side.

On Thu, Aug 7, 2014 at 10:01 AM, Éric Lemoine [email protected]
wrote:

Indeed, unless they use a modifier that we're not aware of.

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Petr Pridal
(managing director)

Klokan Technologies GmbH
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Tel: +41 (0)41 511 26 12
Email: [email protected]
Web: http://www.klokantech.com/