[X] My Assistant

[djellison]

Late last week I stumbled upon a few HiRISE derived DEM's (Randy Kirk works his magic once again!)

http://webgis.wr.usgs.gov/ftphirise/index.jsp (URL now down)

I'm working on both Vic Crater and the Columbia Hills. Fortunately, now I've got a Mac, I can use ISIS. I've figured out a fairly simple flow ( isis2raw as 16 bit unsigned, and then imported into Photoshop ) to take DEM CUB's and make 16 bit PNG's

Just to demo how important that is for me as an animator - sliced comparisons of 8bit vs 16 bit.

A busy week unfortunately, but animations of various sorts are in the pipeline.

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[djellison]

The cliffs are a bit rounded off, just a symptom of the resolution (1m per 'pixel' for elevation) really.

And, to the very best of my abilities, they are accurate for elevation, as close as I could possibly make it. The clincher is that rendering the Columbia one from the landing site - it's a perfect replica of the success pan images of the hills.

The proper movies are here - http://planetary.org/blog/article/00001423/ - although I intend to update the Columbia one later today - links later Randy Kirk got some nice emails about them, which is good because it's his hard work that made the data, and his kindness that put it 'out there' for nutters like me to play with.

Doug

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[dilo]

The proper movies are here - http://planetary.org/blog/article/00001423/

Now I can see them and are superb! Thanks.
What do you think about adding a local high-res texture based on last panoramas, all around the MERs? I think this would add dramatic realism, reducing also the innatural contrast between rovers and smoothed DEM terrain...

[djellison]

I think this would add dramatic realism

Two problems with that. If I had, say, 1cm/pixel imagery around the rover - then my image map would have to be 1cm per pixel. There isn't an easy way to accurately place a second texture on top of the MRO one without actually making the whole thing 1cm pixel. That would mean a texture 800,000 pixels across. No cigar. I went down that road with CTX - on - HRSC DEM's. It was a bloody nightmare, and the results didn't pay off.

The other problem is that at the moment, it all sits together quite nicely. Panoramas don't make good maps very easily.Only a few M from the rover, it's warped and distorted beyond the point of usefullness. ( for eg - http://pds-imaging.jpl.nasa.gov/data/mer2-...8l000m2.img.jpg ) and for the brief moment we are close to the rover, it wouldn't be worth the hassle.

Adding terrain meshes to the Victoria crater one is something I've already had a look at ( I thought the capes might benefit ) but given up on. The meshes themselves just don't stand up to the level of quality to make it worth while.

Always helps to actually publish the damn thing http://www.dougellison.com/?p=5 is now working. That, for now, is my last treatment of the Columbia one. What I'd REALLY REALLY love to be able to do, is some sort of realtime thing where you can drive around it on a quad bike. I'm sure Half Life 2 could manage it, but I just don't know how to put a million polygons into a game like that

Doug

[dilo]

Doug, I perfectly understand the issue you described, I had same problem when I tried to realize a "power of 10"-like movie initially showing all the red planed and then zooming on one rover (Emily suggested such idea long time ago, do you remember?).
Now I solved the issue by making a dedicated POV-RAY script who shades between various textures with different scales, anyway I abandoned the mars-zoom idea due to absence of time (for the moment!). Anyway, this idea is working well only if you strongly zoom on a planar surface, so is not applicable to your 3D DEM... I think the best way to avoid use of mega-textures is to overlap a local, texturized "mini_DEM" surface on the big one, eventually using 3D terrain model computed from MER stereo cam (someting like this was available on venerable "Maestro" JPL software... now I do not know where to find it). In the outer parts, such mini-DEM should appear progressively shaded in order to have a smooth transition effect. I know is not simple, it is only a suggestion for possible, future works...
About your last treatment of the Columbia movie, I like it very much. My only observation is about the colors: personally, I would like more saturation, with different hue between red terrain and a yellow artificial sky... What do you think about?

[djellison]

What do you think about?

I think you should have a go yourself

I know what you mean about the colour. The sky colour is, imho, quite accurate. The ground colour is a little washed out. The simulation from here http://www.marslive.co.uk/?p=5 is a better looking product, BUT, the orientation of the sun when rendering, and when the HiRISE image was taken would contradict. The sun has to be to the west, and reasonably high, to be honest to the shading of the texture on the surface.

I'm not touching it again for a long time. I'm happy to put the 16bit PNG DEM up somewhere if you want to grab it and have a go.

Doug

[Kevin]

I'm not touching it again for a long time. I'm happy to put the 16bit PNG DEM up somewhere if you want to grab it and have a go.

I would love to take a stab at this in a realtime stereo visualization environment. If the 16bit PNG DEM were available I could probably get something up and running in a day or two. It would be a real test for my system.

Cheers,
-Kevin