[ptx] Wished feature

[JD Smith]

On Wed, 2006-08-09 at 09:36 +0200, Pablo d'Angelo wrote:
> Daniel M. German schrieb:
> > Here is a feature that I wished existed in hugin...
> >
> > Sometimes when I am working with 360 degrees panoramas I'd like to
> > experiment by placing the center of the image in different places.
> >
> > Currently I need to select the corresponding image to be the center
> > and set its yaw to zero, then optimize again.
> >
> > What I'd like is the ability to recenter the image without having to
> > recompute the optimization, in a more interactive way.
> 
> Yep, that would be very useful. Actually, a way to rotate the whole panorama
> by entering some yaw, roll and pitch angles would be very useful (and a bit
> more powerful than just rotating by yaw). Haven't had time to figure out the
> formulas to do this. Anyone interested? This could be also done
> interactively in the preview.
> 
> PTGui has such a feature and it seems to be quite useful.

Wouldn't this replace the functionality of the anchor image and position
within it?  It might be confusing to have both, but an interactive
preview in which you can drag the full image to change its yaw center
(wrapping around) and pitch would make horizon adjustments quite easy,
and things like vertical panos also trivial.  

If one could make a mapping between "anchor image position" and the
global yaw/pitch settings, you could make re-optimizing after
interactive adjustment straightforward.  So the steps would be:

     1. By default pick the central (by filename) image as anchor for
        optimization.
     2. Optimize.
     3. In the preview window, enter the "position panorama" mode, and
        drag the yaw and tilt of the entire pano until satisfied (yaw
        only for 360 degree images, with wrap-around).  
     4. To fix "sloping" horizons, enter "rotate panorama" mode, and
        drag to change the pitch.
     5. Map these global changes back to a choice of anchor image, and
        it's pitch/roll/yaw, for re-optimization.

Then you could eliminate the "Fit" and "Center" buttons in the preview
pane, since by default the image would both fit and be centered (I'm not
sure anyone would ever want an off-center pano with black space to one
side; I tend to hit those fit and re-center buttons alot).  A question
remains on what to do as the pitch is changed... expand the vertical
extent of the preview window in real time?