USGS Heightmaps?

[diabloblanco17]

I've been browsing around the USGS website in search of some locale-specific heightmaps that I can use in a realistic bump map for a planet texture I'm making, but all I've found are shaded relief maps. Does anyone know where I can find the basic elevation data (preferably in a form I don't need to convert, like a simple image file that displays greyscale elevation data) used to generate these relief maps?

Thanks in advance.

[selden]

You need to start with DEMs (Digital Elevation Maps). Then you need a program to convert DEM format into bumpmaps or (better) normalmaps. A good freeware program for this is Wilbur, which is available at http://www.ridgecrest.ca.us/~jslayton/software.html

[jestr]

Hi Diablo,this seems to be quite a good site for downloading the Shuttle SRTM 90m height data

http://srtm.csi.cgiar.org/SELECTION/inputcoord.asp
you can choose from a couple of different formats,like Selden said though you will most likely need some software to convert from DEM to bump/normal map.

EDIT:If you download and install 3DEM from here

http://www.visualizationsoftware.com/3dem/downloads.html
You can open the GeoTIF files from the above site and save as a DEM.
Then use Wilbur (see Seldens link above) to convert to a NormalMap.Jestr

[diabloblanco17]

Thanks a bunch, guys. I've got everything I need now, though I'm having some trouble converting the DEM's to bump maps. The conversion works just fine, but the end result is an image with so little variation that it might as well be an inverted specular map. The land is almost totally white, and I can only just barely see the difference between the plains and mountain ranges. This is using GeoTiff's (converted to DEM's in 3DEM) of Japan downloaded from the SRTM site jestr linked to.

[John Van Vliet]

hi well it turns out that the usgs dem files are 16bit gray scale images
so i use imagemagick to do a convert

ex
rename 1234.dem to 1234.gray
you also nead the size it is the same as the shadedrelief map

convert - depth 16 -size ???x??? 1234.gray -depth 16 1234.rgb

convert -depth 16 -size ???x??? 1234.rgb -depth 16 1234.png

then open in gimp
gimp suports 16bit grayscale.png's as a rgb .png and not as a gray.png

then save it as 1234a.png and there you go
you now have a 24bit bump map that neads to be 8bit for celestia

[diabloblanco17]

Ok, problem solved. I simply changed the display method to "height code" and changed the display colors from green, yellow and red to black and white. I'll post something when I get the bump map matched to the color map and rendered in 3ds Max.

[diabloblanco17]

And here's what it looks like with the bump map baked into the planet texture:



1280x800

[Don. Edwards]

Is this for one of your Star Wars prjects? It is actualy quite nice. Also what are you rendering it in. Is it Celestia or another 3D program?

Don.

[diabloblanco17]

Yep. I'm doing a series of images that depict several Star Destroyers laying waste to an inhabited planet. Needless to say, making the planet is taking a while. If you want to follow my progress, I've got threads on it here and here.

I'm using 3d Studio Max 7 to render everything.

[Don. Edwards]

I wish that 3Ds MAX had an easier learning curve. I have tried and all but given up. I can use Bryce fairly good though. Although I find the renders of planets in Bryce are just missing something.

Don.

[John Van Vliet]

if you are intrested the heigh/normal map i use is the gotpo30 map the map IS BIG 32k in 8 parts at 30meg each

however i am going off line to switch to gnome from win xp

alsw my upstream sped is slow 5 to 7 k
comcast dose a nice job for downloase