Richard,

I was so impressed by the images you shared with me, and it looks like you have the kinks out of the HUD setup. This is a real gift to the SL community. Looking forward to seeing the RL design concept as well...

Nina/Avi

In the RL considerations at The Tech we have two places where panoramas might work.One would be in the round theater in the Life section on the second floor. Also there is an underused, almost secret, opening in the golden tube exhibit. Here we can see the golden roots of our valley. This area may lend itself to a historical panorama of San Jose. Maybe each entry could activate a different view.

I've uploaded a test image named IMTest.jpg to the project wiki. It is a panorama stitched from 6 avitar snapshots taken in Second Life.

The parameters here will produce a 2000 pixel diameter polar projection with a 300 pixel "hole" in the middle, which accounts for the "missing" space below the field of view of the "camera".

The ImageMagick convert command will transform the image in one file and place the result into another. The the mogrify command destructively transforms an image and places the result in the original file.

The -distort option using the Arc method appears to be the correct option choice to carry out the necessary transform. Arguments for the Arc method are documented as:

"Arc the image (variation of polar mapping) over the angle given around a circle. Arguments:

arc_width rotate top_edge_radius bottom_edge_radius
where all but the first argument is optional.

arc_width The angle over which to arc the image side-to-side
rotate Angle to rotate resulting image from vertical center

top_radius Set top edge of source image at this radius

bottom_radius Set bottom edge to this radius (radial scaling)

The resulting image is always resized to best fit the resulting image, (as if using +distort) while attempting to preserve scale and aspect ratio of the original image as much as possible with the arguments given by the user. All four arguments will be needed to change the overall aspect ratio of an 'Arc'ed image. This is a variation of a polar distortion."

Setting a rotate angle of zero places the center of the panorama at 12 o'clock in the resulting polar projection. For the bottom radius, a value of 150 is a reasonable size for this image (we'll need to experiment a bit once we characterize the real life camera set-up).

So the following command line did the trick:

convert -distort Arc 360,0,1000,150 IMTest.jpg Test.jpg

Technically, a radius of about 350 for the center hole produces more correct geometry in the pavement, but it leaves a gaping large hole in the center because camera coverage stopped a bit too high.

Presumably the ImageMagick composite option can be used to paste TheTech logo into the hole in the center of the image, but I haven't actually tested that yet.

Note that the white center hole, and the round image on a black background are accomplished by leaving a one-pixel white line in the top and bottom of the pano image. ...again we can easily add those to the stitched camera output with an ImageMagick command, I suspect.