Tutorial: Converting a DEM to a heightmap

[someguy2000]

@TrickyVein,

 

Thanks! Regenerating the terrain textures is a breeze (relative to terrain meshes, anyway), and I still need to touch up the landscape textures (adding dirt paths, debris, etc.). I'll stick with it - I appreciate the pointers!

[TrickyVein]

Just for funsies I've been looking at parts of the Grand Canyon for a project and wanted to post some of my initial results here:

 

http://imageshack.us/a/img841/2978/screenshot87l.jpg

 

Way too big.

[PossiblyErich]

I'm feeling like a moron right now, I have no idea what needs to be imported for elevation. The only valid elevation file it shows me in the folder is .HDR file that's 1KB, and VTP says it can't import any data from, which I can understand considering the filesize.

 

 

That's what i'm looking at for what I got from the USGS website. This is the portion of the Grand Canyon that Grand Canyon village is in, for a point of reference.

[TrickyVein]

In VTBuilder, if you pull under 'layer' from the menu to 'import data' you should be able to select 'elevation' from the message box - then, you can select the .hdr file and the elevation data should be drawn in the viewer. BTW, for 1 arcsec resolution I feel like 50mb is a bit small. Are you sure it finished downloading? Just to double check.

 

All of that other stuff is for georeferencing and projecting the data into a coordinate system which we don't really care about.

 

The 'flt' extension is for float data - I guess it's stored that way before it's binned into 8-bit or 16-bit which is what we want.

 

You can't display floating data - pixels have absolute values between 0 and whatever bit you're dealing with - so the real, floating data may have a value of 125.82349080432 but it's binned into 8-bit (values between 0-255) and assigned a value of 126.

Edited August 4, 2013 by TrickyVein

[PossiblyErich]

I've downloaded the 1 arcsecond resolution for that area again and yeah, it comes out exactly the same size. Still can't import the .hdr either, it still returns the error "Couldn't import data from that file".

[TrickyVein]

What is your OS? The VTP documentation doesn't say, explicitly that it's compatible with Windows 8.

 

I can't find anything else through looking at the online documentation, but you may want to for yourself: http://vterrain.org/Doc/VTBuilder/en/

 

Another possibility is that you've downloaded 32-bit data from the USGS which I don't think VTBuilder can read. Only 8-bit and 16-bit are allowed, methinks.

[PossiblyErich]

I run 7, so it isn't that.

Not sure how to tell if I have downloaded the 32bit information from the USGS. As far as where it says "format", I have selected GridFloat since it was the first option, but there's also ArcGrid and IMG. Could it be there?

[TrickyVein]

Select the arcgrid format.

 

Wow - these little things you look over - that should really be in the tutorial. My bad. That's really important and for some reason I completely glossed over it. Thank-you so much for posting your problem here.

 

Sorry! Download it again and everything should work the way it's ought to - and now the fun part begins.

[PossiblyErich]

I'm about to the point where I can export, but I'm not sure how to do IBM bit order. Nor checking if it is interleaved or not. I'm only moderately familiar with GIMP, let alone photoshop.

[TrickyVein]

Are you using GIMP? Get photoshop. CS2 is free, now. All you have to do is register an account with Adobe and they'll give you the software. I'm afraid that photoshop is all that I'm familiar with.

 

If you save the image as a .raw then you should be given those options when you go to save.