Improved Performance : Partial panoramas

[Velociped]

I was wondering about the heavy CPU load for partial panoramas and I made some tests with different settings.

For a partial panorama with horizontal 360° but less than 180° vertical view, Pano2VR suggests a cylinder panorama. It turned out in my tests, that cylindric panos need 50% more CPU-power for autorotation than a spheric panorama!!! (MacBook, Dualcore Intel, OSX10.5.8, Flash 10)
Maybe because of some "native" panorama functions built in the Flash-player?!

1. To benefit from this fact, it's necessary to stitch partial panoramas as shperic (equirectangular) rather than cylindric! (Hugin works fine)
2. Open the panorma in Photoshop and expand the canvas size to the correct equirectangular ratio 2:1 (not scaling, just fill the space with some background! Black will do ).
3. Open the file with Pano2VR as "equirectangular".
4. Zenith an nadir now just show the empty background. To cover this in the final compilation, set top and bottom limits in the "viewing parameters".
5. Compile
Done!

Now you have a full spheric panorama that shows only the relevant part. The file size is a bit bigger because of the adde space. But it uses way less CPU-power than the default cylindric view and it rotates much smoother on slow machines!

[360Texas]

Yes, this is the correct work flow. We have done this before in the World Wide Panorama Event "Time" June 2009

http://www.worldwidepanorama.org/worldw ... -5605.html

Instead of a black background in photoshop you can fill with different textures like grass, sky or blended colors.

And:
http://www.worldwidepanorama.org/worldw ... -6900.html

http://www.worldwidepanorama.org/worldw ... -3258.html

You are not limited to using stitched fisheye images. Any 2:1 say 5000 x 2500 pixel dimensioned graphic or photograph can be delivered to the viewer.

And no the images are not necessarily larger in final format . Yes, we use 6000 x 3000 16bit .tifs and about 140mb. After converting to flash all the above are about 1.5 - 1.8 mb Flash .swf.

Are we having fun yet ??

[Velociped]

Thanks Dave!

It was new to me that cylindric panoramas draw that much more CPU-power! To me this is the important point because it limits the maximum size on slow computers! But now I know how to fix it!