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Unmanned Spaceflight.com _ Opportunity _ A Tribute to Opportunity and her Epic Journey

Posted by: Nirgal Aug 27 2011, 04:21 PM

Although this is still a work in progress, I would like to share with you a preview of a new project I'm working on:

http://www.youtube.com/watch?v=QNCnzJFiELY&feature=player_detailpage

(The video is best viewed in HD resolution (720p), fullscreen and volume turned up for the background music.

Click here for a (still experimental) http://www.youtube.com/watch?v=StuNOUqMGPE&feature=player_detailpage (view in HD if possible)

Here is some background info for the technically interested:

The whole DEM consists of about 3 billions of triangles, modelling Endeavour's west rim at full HiRISE resolution of 25cm/pixel. Unlike the standard method (of draping hi-res 2D imagery over a lower-res 3D DEM), the new technique provides real 3D geometry down to the highest resolution level (i.e. 0.25 m/pixel for HiRISE). This results in a more realistic visualization because each single pixel contributes genuine 3D information - as you can see for example in the low sun images where each pixel is, in principle, capable of casting its own tiny shadow.

Rendering this kind of DEMs has been a real challange, though. At 0.25 m post spacing, the models are about 16 times larger than the already huge standard HiRISE DEMs at 1 m/pixel. So together with the mosaics of several full-res CTX frames ( that I'm merging the DEMs with for context ) this results in DEMs of several billions of triangles. Unfortunately this seems to be too much to render with conventional 3D programs such as 3ds-max that are usually limited to some dozens of millions of polygons, but can't readily handle several billions. This is why I decided to write a specialized gigapixel-ready terrain visualization software with a raytracing kernel for realistic soft shadows and global illumination.

As this is a rather time consuming work, it is not finished yet (still missing color support and the movie processing chain is still too slow for producing longer flyovers ... )

Hardware is another limiting factor (currently I'm running out of RAM on 24 GB blink.gif ... but the new gear (48 Gigs + 12 cores) is already on the christmas wishlist...

Nevertheless the first results look promising so I thougt I'd share some impressions with the UMSF community
smile.gif



Posted by: mhoward Aug 27 2011, 04:39 PM

Astonishing!

Posted by: ugordan Aug 27 2011, 04:49 PM

Spectacular!

Posted by: eoincampbell Aug 27 2011, 05:13 PM

"Epic" indeed!

Posted by: Lucas Aug 27 2011, 05:13 PM

Wow! That is truly awesome and inspiring!

I don't know if you're taking requests, but it would be really neat to see a model of Opportunity at some spot in her trek and do a "fly over".



Posted by: MoreInput Aug 27 2011, 09:35 PM

Absolute fascinating and awesome, Nirgal!

Thanks for this views and still waiting for more of them!


Posted by: ustrax Aug 27 2011, 10:34 PM

in good plain portuguese...f***-**!!! blink.gif

Posted by: Oersted Aug 27 2011, 10:50 PM

Ah, I thought that would be c******! Ustrax... smile.gif - Anyway, I agree with the sentiment!

- Do you plan to make a version without vertical exaggeration, Nirgal?

Posted by: siravan Aug 27 2011, 11:18 PM

Excellent job! Do you use a flat plane or a sphere (to represent Mars curvature) as the base?

Posted by: walfy Aug 28 2011, 03:59 AM

Some of the best flyovers of Mars I've seen yet. Please keep this up.

Posted by: CosmicRocker Aug 28 2011, 04:01 AM

Oh, wow! I am speechless.

Posted by: gregson Aug 28 2011, 09:42 AM

Beautiful!!!
But i think the vertical scale is exeggerated -I see this on the sand dunes-end of the animation. It was made intentionally?

Posted by: Nirgal Aug 28 2011, 11:34 AM

Thank you very much for the nice comments on my work. glad you like it !

As there were questions about the vertical scale of the model I would like to point out there is no intentional vertical exaggeration of the geometry as you can see in this image comparing a "ground truth" photograph taken by the rover as of Sol 2679 on the left hand with a simulated view of the 3D model from approximately the same position and viewing angle (the shadowed slope in the right image is due to a lower simulated sun angle)



It is true that in my renderings I always try to emphasize & accentuate the topography for reasons of viewing aesthetics, but this is largely due to my using very low sun illumination angles just by simulating late-evening conditions with long shadows (this is just the same as landscape photograpers here on earth would do in order to accentuate the shape of dunes and mountains) In addition to that I tend to use settings of my simulated camera and darkroom that result in contrast enhancement and lens-induced geometric distortions (again the same as landscape phoptographers would do here on earth as well :-)

That being said: although the large scale topography of the model is exactly registered to official MOLA and HRSC DEMs
there remains uncertainty in the small-scale variations of the surface model as with any single-image based 3D reconstruction method namely in the presence of albedo variations. Without albedo variations (i.e. fully dust- or ice- coverd areas) I found the mean reconstruction errors in my experiments to be less than ten precent compared to ground-truth DEMs but the error can be larger in presence of large albedo variations.
Fortunately, the single-image method complements nicely with stereo-based methods that are immune to albedo variations (but provide only a fraction of the resolution and have troubles in texture-less areas).

Although maximum scientific accuracy has never been the main goal of my work (that is intended for porposes of visualization and aesthetics only - in the sense of "Martian Landscape Photography" wink.gif I do plan to further improve the overall accuracy of my models in the future by incorporating more stereo-derived base DEMs. I'm especially looking forward to the official Endeavour HiRISE DTM that I think will be published in the near future and that I expect to provide a very accurate base-DEM for that area smile.gif

Posted by: tedstryk Aug 28 2011, 01:12 PM

Simply amazing!

Posted by: Stu Aug 28 2011, 02:30 PM

Stunning, just... stunning... ohmy.gif

Posted by: JayB Aug 28 2011, 03:19 PM

I'm guessing you don't spend a lot of time watching television in your spare time smile.gif

Fantastic work

Posted by: neo56 Aug 28 2011, 03:39 PM

Absolutely amazing ! The HiRISE team will certainly be interested by the programming you did !
Let's hope you will succeed in solving the "color" issue !

Posted by: djellison Aug 28 2011, 04:45 PM

I know just how hard that was to do.... it's breathtaking. Congrats!

Posted by: nprev Aug 28 2011, 05:12 PM

Absolutely wondrous, Nirgal; thank you so much for sharing it with us!!!

Posted by: MahFL Aug 28 2011, 05:30 PM

Stupendous.

Posted by: machi Aug 28 2011, 08:36 PM

It's gorgeous work!

Posted by: Oersted Aug 28 2011, 10:46 PM

Thanks for your comprehensive explanations Nirgal!

QUOTE (Nirgal @ Aug 28 2011, 12:34 PM) *
In addition to that I tend to use settings of my simulated camera and darkroom that result in contrast enhancement


I think that this particular facet of your post-processing should be toned down a little bit. I love the low-sun angle and the vertiginous lens work, but I think the very punchy contrasts are probably a bit overdone.

A small "artistic" suggestion: when you come down from up high with your camera you could maybe fly through a few of those wispy high clouds we have seen in MER images. Would be a good effect to complement your lower ground-hugging fog layers and atmosphere opacity.

Can't wait to see more of your amazing work!

Posted by: antoniseb Aug 28 2011, 10:56 PM

Very nice. What software tools did you use to make it?

Posted by: PFK Aug 28 2011, 11:12 PM

Good grief, that's astonishing and inspirational - great stuff!

Posted by: Bjorn Jonsson Aug 29 2011, 12:24 AM

Wow, this is stunning, very near the top of my list of impressive stuff I've seen here.

The DEM is extremely detailed and realistic and in addition, the shading algorithm seems to result in something that looks very realistic.

The lack of software and/or hardware that can handle *lots* of triangles is a familiar problem.

Posted by: Zeke4ther Aug 29 2011, 05:44 AM

Beautiful....and breathtaking. Can't wait for the colour.

Posted by: Robert S Aug 29 2011, 08:31 AM

I'm inpressed and amazed!

Beautiful! Absolutely beautiful!

Thank you!

Posted by: Leither Aug 29 2011, 04:48 PM

Großartig!!

Truly awesome......words fail me. The sheer beauty....

Has to be one the best planetary animations I've ever seen. Fantastic work!


Posted by: Nirgal Aug 29 2011, 09:29 PM

Thanks again for all the overwhelming feedback and comments that is greatly appreciated and very encouraging to continue with this work smile.gif

In the following I will try to answer some technical questions that came up:

QUOTE (antoniseb @ Aug 29 2011, 12:56 AM) *
What software tools did you use to make it?


The main processing chain ( 3D model generation and rendering/raytracing ) is all self-written C/C++ software.
(though with a rather ugly and spartanic command-line user-interface but specially tuned to manage 3D models
consisting of a dozen billion polygons, which I found none of the existing programs could handle :-/

For the pre-processing and preparation of the raw data (map-projection) I use the great ISIS3 package (freely available from USGS).

Nothing special for post-processing: Photoshop for still images and the usual video encoders (ffmpeg) for turning the rendered image
sequences into movies.


QUOTE
Do you use a flat plane or a sphere (to represent Mars curvature) as the base?


just a flat base with a simple trick to simulate a curved horizon on-the-fly within the raytracer by
subtracting a curvature-correction-value (based on the distance to the observer) from the current height
above the flat base, while advancing the viewing ray away from the observer through the geometry's
bounding volume hierarchy.


Posted by: Nirgal Aug 29 2011, 09:39 PM

QUOTE (Oersted @ Aug 29 2011, 12:46 AM) *
... I love the low-sun angle and the vertiginous lens work, but I think the very punchy contrasts are probably a bit overdone.


Yes, this is a good point. Part of the problem (apart from my not always resisting the temptation of turning the knobs too much wink.gif lies in the general difficulty of preparing images to look equally good on different output devices (google "gamma-correction" ) Incidently, I just now found out that the video does look quite different (too crisp and too contrasty indeed) on monitors other than the good old "warm & soft" analog CRT display that I normally use.
Another problem is video compression: After uploading to youtube, I found that the encoding/compression caused further contrast and gamma correction to the point that many subtle details in shadowed areas got lost.

As for the cloud layers: yes this is something quite high on my TODO-list. But here, too, one should be careful not to overdo it: I once saw an animation involving artifical Mars clouds that looked very unnatural (way too "earth-like"). It will be a challenge to simulate the very faint and subtle appearance of the clouds as I imagine them to look like on Mars in reality.

Posted by: Sym05 Aug 30 2011, 02:36 PM

Simply fantastic.
Thank you!

QUOTE (Nirgal @ Aug 27 2011, 05:21 PM) *
Click here for a (still experimental) http://www.youtube.com/watch?v=StuNOUqMGPE&feature=player_detailpage (view in HD if possible)

Did you considered the possibility to use the native Youtube 3D features allowing viewers to choose their preferred option (Red/Cyan, Green/Magenta, Side by side, etc.)?

The videos displayed on a 42" HD TV are amazing .... 3D with active glasses should be better tongue.gif

Posted by: Oersted Aug 30 2011, 11:17 PM

QUOTE (Nirgal @ Aug 29 2011, 10:39 PM) *
Another problem is video compression: After uploading to youtube, I found that the encoding/compression caused further contrast and gamma correction to the point that many subtle details in shadowed areas got lost.


Oh yes, I know about that! Youtube absolutely ruins your uploads, especially in high-res. I suggest you maybe look into vimeo...

Posted by: hendric Aug 31 2011, 02:23 PM

Nirgal, you win the UMSF internets. Now just get Scooterlord's MER model into that, and hook up with StephenV2 to get an IMAX movie finished! smile.gif smile.gif

Posted by: DFinfrock Sep 1 2011, 01:15 AM

QUOTE (hendric @ Aug 31 2011, 03:23 PM) *
Nirgal, you win the UMSF internets. Now just get Scooterlord's MER model into that, and hook up with StephenV2 to get an IMAX movie finished! smile.gif smile.gif


Now that's an All-Star cast! And perhaps Stu and Astro0 could produce the movie's promotional poemster! smile.gif

Posted by: djellison Sep 1 2011, 04:53 AM

QUOTE (hendric @ Aug 31 2011, 07:23 AM) *
hook up with StephenV2 to get an IMAX movie finished! smile.gif smile.gif


StephenV2 is militantly opposed to using CGI in his IMAX movie. Thus, despite the beauty, accuracy, splendor and grandeur of Nirgal's amazing work.....StephenV2 would not, by his own rules be able to use it.

Posted by: Nirgal Sep 1 2011, 08:50 AM

yes, making animations to be shown, e.g. in Planetariums is something I do consider as a future option.
However, as I already wrote, this is still a work in progress and I have to make the homeworks first.
Among other things there is one important issue that needs to be resolved before I can consider this finished: namely the support of color.
Although black&white landscapes do have their own aesthetics (think Ansel Adams ;-) color (like music) is absolutely essential to transporting emotions in a film.
(What would the Red Planet be without Red ? wink.gif

So, although I am very satisfied with this first prototype video as a "proof of concept", there is still a lot of research and programming work to be done until the project
could be considered anything near "production ready".
Until then, I'm afraid I can't take any requests because I fully need to concentrate on the research & programming.
Hardware needs to be upgraded too (12 cores + 48 Gig RAM is a minimum configuration for rendering those multi-gigapixel DEMs in serious production quality)

If all goes well I think the first color versions could be ready sometime mid next year.
In any case, I will keep you updated here at UMSF smile.gif

Posted by: hendric Sep 1 2011, 03:12 PM

I understand that's his view point on the current Saturn movie, but I think for Mars there is just too much data outside of pure pictures such as DEMs that to not include them would be a big loss to any IMAX treatment.

Posted by: AdamH Oct 4 2011, 08:50 PM

Just wanted to add my kudos. Absolutely stunning work, Nirgal.

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