[X] My Assistant

[ngunn]

Viewing the latest wonderful Home Plate mosaics prompts a thought that has often occurred to me before. Why isn't it possible to join up the ends of a panorama to allow for continuous panning in either direction? On the face of it this would seem to be a relatively simple thing (hugely less complicated than a full virtual reality package) and highly desirable for 360 degree views, yet it's never done. Can somebody explain to me where the catch lies?

[AndyG]

Hi ngunn,

I've stuck together the quarter res. image created by James into a simple Flash package. Left to go left, right to go right.

It's hosted here in an html page. Bewarned - it's over 900kb! Obviously 99% of that is the image, and it might fall over without a preloader on bad/slow connections. If it doesn't work, try downloading the source shockwave file from here (right click and save-link-as) and drop it into a browser - or run it on a standalone player.

I'm only duplicating the image twice in Flash, so there's a slight bump at the transition. A triplication (moving one image while off-stage) would be smoother. But the pan's ok, I think.

I've added 5 ten-degree markers at the page top, with a rough angle measured on the middle one (taking the right edge of Eldorado to be ~north). The seam is at about 189 degrees, really only visible in the sky, so it's a great job, James!

If you right click you get the default flash option to zoom in. I've spent a happy few minutes looking at the horizon as I spin in my spacesuit boots, by getting the ten degree markers the right distance apart at a reasonable viewing range. I think you are right in that continuous panoramas do bring a certain something to the views people are making...it frees up where you want to look at - it is more like being there.

Since I can see the potentials, I may well have to play with this further...

Regards,

Andy

[ngunn]

Since I can see the potentials, I may well have to play with this further...

I'd be interested to know, now that you've done it for one image, how much work will you have to do on each further image you want to 'panify'? Can it be automated so that any image can be opened this way even by computer dummies like me?

Also, while you're 'playing' (to such excellent effect) - once you've got around to all the big MER 360s there are also some inward-looking 360s to consider: the map of Titan for example (or Iapetus, or Ganymede, or Venus, or . . .)

[AndyG]

Thanks for the comments! To answer the questions...

Widening the applications of the program:

I think the most practical way to achieve this would be to use a very small external .xml file to load the .swf with the desired image, the image height and width, and where north is. The resultant (picture-less) .swf file size would then be tiny - less than 10k. The scripting in the Flash would need to be re-written to load the image and calculate the correct sizing/scroll rates from any particular image's data - but that's not difficult.

A user would need to amend the xml file for use with different images, however a simple edit & save in Notepad would suffice.

It would be much more work to completely automate this process: i.e. select a file from a list and let 'er rip.

Inward looking 360's:

This is similarly straightforward. Though for global views there'd be extreme distortion at the poles unless the image was treated. This would give me nightmares, I think: the maths is ok (with a bit of cheating) and I believe Flash is good at squeezing/stretching bitmap images (I've personally got no experience of that), but it would run much less smoothly unless the image sizes were small - which perhaps rather destroys the idea of the big panorama.

3d Views:

There's obviously no problem entering an anaglyphic panorama as a single image. And it would be ok to enter a separate left and right panorama - a semi-transparent image offset over another is ok in Flash. The only hassles I can see with that would be getting the transparency (alpha) and the offset right, but a slider/controller would sort that out.

Andy