Accurate height maps ?

[paulselhi]

Hi all, first post here and let me first say what a neat program Celestia is however my first question to you may be a bit off topic

I am using cinema 4d to render out an animation of mars and rather then fill the post with images here is a link to what i have so far

http://www.black-and-white-to-color.com ... wtopic=855

I sued a 16k color map and a 8k bump map in a displacement channel with sub poly displacement, for those who don't know SPD is a render effect which subdivides a mesh ( in this case 6 times) based on the bump map, it means i can get high detailed displacements ( not bump illusions but actual deformation of the geometry)

The thing is scale, can someone tell me how accurate the tonal scales are on these sort of bump maps ? You See in my renders valles looks a lot deeper than Olympus is high

I set my sphere up to be 1/1000 of the size of mars and set my displacement to be 1/1000 of the height of Mons, is the maths right here ? If i scale the radius of the planet by a factor of 1000 should the height map be scaled by 1000 ?

I used a displacement method known as intensity centered where white is high grey is flat and black is low ( i could have used intensity where black is flat and white is high)

Of course a lot depends on where mars datum is, if datum is close to the area of mons then mons would be nearly 26km above it's surroundings but i suspect that most of the are that mons is is well above datum

can anyone give me any hints as to how to accurately use a mars bump to displace a mesh so that the mons and valles are correctly proportioned

Looking forward to your ideas

Thanks
Paul

[t00fri]

You should always use the /official/ elevation maps. They are ALL in raw binary (signed) 16bit integer format. Some are little-endian some are big-endian. Only by exploiting the full 16bit lever arm you may get a noisefree quality in the end.

You have to look up the width in the accompanying files and possibly sew tiles together at the 16bit level, which is easy with a few lines of code.
The format does NOT have any headers.

Bye Fridger

[selden]

I have essentially no experience in matching various datums, but I would have expected it to be mentioned in whatever document you used to get the volcano's height.

Mars certainly isn't a sphere. Much of its northern hemisphere is well below the average datum. Olympus Mons seems to be right on the edge between a low area and a higher one.

Google Mars might help.

[paulselhi]

I used marios Textures from space graphics and the bump map is 8K tiff

I suppose my best bet is to ask nasa ( i am sure they will have time to look at my renders !!) and see if they think the renders are feasable

Strangeley enough ( maybe synchronicity) i could not sleep and turned the tv on at about 5.am and there was a schools space program on, the renders of mars in 3d made me happy as they were not even close to my quality, and to think someone got paid to do them !!

Now in this program the volcanoes on mars were like huge warts sticking up from the surface, very obvious even from distance, i wonder if they were exagerated or not

I will have to do some more research, thanks all..

[t00fri]

I used marios Textures from space graphics and the bump map is 8K tiff

Mario is a good friend of mine and we did many joint experiments to suppress noise in gigantic normalmaps of mars and earth (>= 32k x 16k).

Mario's textures are generally great, but his /published/ heightmaps are ALL truncated to 8bit graylevels. This makes them effectively unsuitable for further processing.

You got to process the 16bit originals yourself if you want good results.

Bye Fridger

[paulselhi]

Thanks any links for the 16 bit originals ?

[t00fri]

Thanks any links for the 16 bit originals ?

Well they are easy enough to find. Just look for MEGR (Mars) and SRTM (84k Earth).
ftp://e0srp01u.ecs.nasa.gov/srtm

For Earth the BMNG arctic server has everything you might ever want to use:

http://snowy.arsc.alaska.edu/nasa/

But that's what the forum is there for. Just look into the threads, use the search engine...incidentally, are you a beginner or rather experienced?

I don't know what your machine can handle, given your "still image" requests in another thread. With 3GB RAM I can easily load and work with 84k x42k monster textures, for example ...Celestia runs with 80-150 fps in 32bit/1600x1200 fullscreen. I wrote a set of custom tools for handling huge 16bit height maps that are VERY fast as compared to allround software.

Bye Fridger

[paulselhi]

relative beginner with celestia, i have played with it before but nothing more than adding vtms etc

More experienced with 3d graphics cinema 4d 3ds max etc

The scenes i want to do are more than celestia can handle (impact events etc) so that is why i want to use C4D.

As you can see from the vid i did i can render out quite well in c4d but if for example i wanted to do a full shot of a planet with it's orbiting moons etc it would be a pain to setup in a 3d app when celestia has all the orbits etc ready made. However for mars with it's 2 moons setup in c4d should not be too difficult ( famous last words)

There is also the added advantage of selectively bringing up labels for features, ease of feature to feature navigation etc and of course the vtms though most 3d apps can do texture switches dependant on say camera distance celestias vtms are very smooth in transition

[cartrite]

I have done some modeling of mars not too long ago.
http://www.celestiaproject.net/forum/viewtopic.php?t=8861
I got my height data from this site.
http://pds-geosciences.wustl.edu/geodat ... mgsl_300x/
cartrite

[Ultron]

I'm looking for accurate height (displacement) maps of mars too.

Unfortunatly I don't know how to open these img - lbl Files
http://pds-geosciences.wustl.edu/missio ... megdr.html

and Marios Space Graphics Site seems to be down.

I would be glad if anyone could tell me where I am able to get a readable high resolution mars displacement map.
I prefer a single image instead of Tiles.

Thanks

Tobias

[t00fri]

I'm looking for accurate height (displacement) maps of mars too.

Unfortunatly I don't know how to open these img - lbl Files
http://pds-geosciences.wustl.edu/missio ... megdr.html

and Marios Space Graphics Site seems to be down.

I would be glad if anyone could tell me where I am able to get a readable high resolution mars displacement map.
I prefer a single image instead of Tiles.

Thanks

Tobias

Just install the professional ISIS3 suite and read the tutorials if you have Linux somewhere. Also have a look at our CelestialMatters site and my texture tools (F-TexTools-2.0 / nmtools-2.0) that work for ALL popular OS.

Website:
http://www.celestialmatters.org/
Forum:
http://forum.celestialmatters.org/

notably this thread of mine
http://forum.celestialmatters.org/viewtopic.php?t=194

You'll find lots of instructions how to do highres Mars normalmaps from the Mola128 scientific data etc.

A whole forum is devoted to my texture tools. Here you find lots of links etc

That's the kind of imaging we are discussing over there...

First a tiny piece of an inverted normalmap from Mola 128 data obtained with my texture tools:


The inversion helps to appreciate the highly detailed and smooth shading the normalmap will provide. Note the total absence of noise since I always start from 16bit binary elevation data!

Here is a bit of the base texture...




Mario has indeed vanished completely from the scene...

Fridger

[Ultron]

Thanks a lot for your great work. The Pictures look really great! But I really have a great lack of time and I wouldn't be able to get into the philosophy of your tools in time. (anyway perhaps I get into it later - these tools are REALLY interesting!)
If there aren't any textures I can simply download I will just use the 4k displacement map I allready own.

[t00fri]

Thanks a lot for your great work. The Pictures look really great! But I really have a great lack of time and I wouldn't be able to get into the philosophy of your tools in time. (anyway perhaps I get into it later - these tools are REALLY interesting!)
If there aren't any textures I can simply download I will just use the 4k displacement map I allready own.

The scientific elevation file that serves as an input is 1-2 GB in size and has 16bit binary format ( <= .img), since extreme data smoothness is paramount for eliminating "elevation noise". This size and format can only be handled with either my tools or with the ISIS3 tools, since normal image manipulation software lacks the appropriate memory management for handling such "monster-sized" textures and cannot read .img files.

If you have no time, then you should better take what you have already.

Just for your info: elevation maps associate an elevation number with each (x,y) point of the global map. If you use an elevation map in normal JPG or .PNG format, you only have 256 integer values (<=> 1 Byte = 8bits) in each point to characterize the altitude profile. This is BY FAR too little for a satisfactory hires display! E.g. the altitude of Olympus Mons on Mars is ~ 27000 meters, about 3 times Mt. Everest! It should be obvious that 256 values are barely enough to map such a large elevation profile. However, with signed 2Byte =16bit numbers reserved for each surface point, you instead have a range from -32768 to +32768 at your disposal. If each digit represents 1 meter in altitude, then you can smoothly map the profile of Mars. This requires a different image format, however.

Fridger

[Ultron]

Thanks for your explanation. Know I understand a little bit better.
Am I right, that your software works like an image converter so I can plug in the Nasa Imagery into my Softimage 7 Software?
Which Format do I get out of your Software?
Is your Software also combining Tiles?

Sorry if my questions are foolish. This is a complete new (very intresting) area for me to work in!

Tobias

[t00fri]

Thanks for your explanation. Know I understand a little bit better.
Am I right, that your software works like an image converter so I can plug in the Nasa Imagery into my Softimage 7 Software?
Which Format do I get out of your Software?
Is your Software also combining Tiles?

Sorry if my questions are foolish. This is a complete new (very intresting) area for me to work in!

Tobias

Tobias,

I suppose you are a Windows user? I don't know your Softimage Software. Here, we are mostly working with the GIMP, since it is cross platform and OpenSource. Celestia is for Windows, Mac OS and Linux, you know...

If you are not experienced with using command line programs and short of time, I would rather guess you might not want to learn what is required for using my tools. These tools are meant really for people who want to get the best available textures in the largest available resolutions. Any existing GUI-based software would fail from the start to handle such big files e.g. at 16 bit level.

There are many possible applications for my tools, but it's really hard to give advice without knowing precisely what you have in mind. This forum is mainly for people using Celestia and so are my tools, although they can be used for other purposes, too.

Anyway, you may want to check the Celestia Motherlode, where you might find what you were looking for. I cannot say anything about quality, however...

http://www.celestiamotherlode.net/

Oh, I almost forgot:

Which Format do I get out of your Software?

Either PNG or highest quality DXT (often called DDS) that is highly efficient...

Is your Software also combining Tiles?

No, for that you will need ISIS3. The .lbl label files are used by the ISIS3 software to assemble the mosaic correctly. A main application of my tools is making tiles (so-called VTs) from "monster-sized", i.e. multi-GigaByte texture files.

Fridger

[John Van Vliet]

--- edit ---

[Ultron]

Danke f?r die nette Hilfe - hier das Ergebnis:
www.icebrecher.de/up/marsInfoFilm2.flv
(mit VLC kann mans abspielen)

Wie siehts eigentlich mit den Rechten auf motherlode aus (kommerziell und privat)?

[t00fri]

Danke f?r die nette Hilfe - hier das Ergebnis:
http://www.icebrecher.de/up/marsInfoFilm2.flv
(mit VLC kann mans abspielen)

Wie siehts eigentlich mit den Rechten auf motherlode aus (kommerziell und privat)?

Hallo Tobias,

...huebsch!

If you plan to publish the video, please include appropriate references about the maps used, Celestia etc...

The licenses of add-ons on the Motherlode may vary depending on the authors. For non-commercial purposes there is usual no problem. Best is to contact the author directly.

Fridger