MRO 3D views, Unbelievable... Options

[Guest_Oersted_*]

I'd very much like to see them without the vertical stretch...

[CosmicRocker]

As I mentioned elsewhere in the forum, the HiRISE site has published over 300 anaglyphs that are viewable with IAS viewer or as PNG or JPEG2000 downloads. This 3D imagery is incredible.

Oersted: Can these images be reprojected to allow them to be displayed without vertical distortion? If not, I'd at least like to see a rough estimate of the vertical distortion for each image for a standard pair of eyes a standard distance from the screen.

How about this? Considering that the distance from our eyes to the screen is the only variable we can easily control that affects the vertical exaggeration we see, why not publish the viewing distance required to deliver a 1:1 geometry for the average pair of eyes?

Can the "convergence angle" published on the anaglyph information page be used to calculate the distance between the camera's position in each pass assuming a constant elevation?

[ElkGroveDan]

Oersted: Can these images be reprojected to allow them to be displayed without vertical distortion?

While not an ultimate solution, one quick way to deal with the vertical distortion is to simply move your eyes closer to your monitor.

This one is a good example (using Stu's bandwidth for convenience sake): http://cumbriansky.files.wordpress.com/2008/12/cd7.jpg

[CosmicRocker]

I just noticed that if you go to their "Stereo Pairs" link there are purportedly, 905 images.

[CosmicRocker]

While not an ultimate solution, one quick way to deal with the vertical distortion is to simply move your eyes closer to your monitor.

I'm far-sighted, so I'd have to use a hand lens to do that effectively. But I do use that trick as best as I am able.

[ngunn]

I would like to echo Oersted's desire to have the relief rigorously calibrated in some obvious way. I've suggested before having a virtual cube (or sphere?) in the corner of the image to provide a scale key in all three dimensions. If you see the cube as a cube and not as a skyscraper it means you're the correct distance from the screen. (I may be wrong but I think that the correct distance would vary from person to person according to eye spacing, and also from screen to screen according to pixel size.) I do think there's a danger in imagining towers where there are in fact pancakes. It throws your intuitive feeling for a landscape completely out of kilter.

[Art Martin]

Another feature I'd like to see, and it's now an inclusion on the software I use for building my own 3D images, is for the results to be displayed as not only an anaglyph, but as cross-eyed pairs, and as animated GIF's where the left and right eye images are toggled back and forth. This prevents the user from having to have the red/blue glasses at whatever computer they're using and also gives people like a friend of mine that is virtually blind in one eye the ability to view the 3D effect.

Anaglyphs and other 3D representations used to be a great deal of work to produce but it's a breeze and inexpensive these days with the software out there. The only limitation I can imagine would be the additional bandwidth required to display the various formats and the little bit of additional time required to produce them.

[CosmicRocker]

The parallax inherent in the stereo pair will always limit what we can see with our eyes on our screens. Ultimately, the best solution will be to use the data to create a Digital Elevation Model which can then be rendered as you please.

Short of that, one common Martian feature that can be used as a sort of universal candle of dimensional proportions are ripples and dunes. The angle of repose of loosely piled grains controls the aspect ratio of such aeolian structures. If the dunes/ripples appear to be too tall and skinny, you can assume everything else is vertically exaggerated by about the same amount. Other natural features can be similarly used with appropriate adjustments for planetary conditions.

[Stu]

I've suggested before having a virtual cube (or sphere?) in the corner of the image to provide a scale key in all three dimensions. If you see the cube as a cube and not as a skyscraper it means you're the correct distance from the screen.

I LOVE that idea. Genius. I often wonder just how accurate the 3D images are, that would be a really useful guide.

[ngunn]

Hey Stu - with the power of your propaganda machine behind it it might even happen! Would you like to join my campaign for wraparound panoramas too?
http://personal.strath.ac.uk/andrew.goddard/pan.html

[AndyG]

Hey Stu - with the power of your propaganda machine behind it it might even happen! Would you like to join my campaign for wraparound panoramas too?
http://personal.strath.ac.uk/andrew.goddard/pan.html

Oops - I promised a few more of these, didn't I? Though do they do anything that the qtvr images don't provide?

Hmmm...I'll schedule in a few days over the Christmas break if there's a desire for more.

Andy G

[ngunn]

Great to hear that Andy. I was very much hoping there would be more - and that the idea would catch on more widely (which is why from time to time I have found an excuse to re-post that link).

Yes they do have advantages over vtr (though the reverse is also true, obviously). For one thing they're a lot simpler. For another you can make them without altering a single pixel of a published panorama - it's a loss-free procedure. The two things occupy different niches in my view.

[Juramike]

...if there's a desire for more.

Wow! Yes! Absolutely! Fantastico! (Thanks for reposting that link.)

[ngunn]

There you go Andy! There were quite a number of similar reactions on the original thread as I recall. You need not be in doubt they will be appreciated. It's the perfect Christmas 'good deed'. Those panoramas have had an unfortunate encounter with a knife and are waiting for your healing hand.

(Note to SantaG: the view from Husband Hill)

[AndyG]

(Note to SantaG: the view from Husband Hill)

Ok. You got it. And surely there's a Phoenix crying out to be done, too - after all, it didn't budge.

AndyG