Author Topic: Glacier N.P. TERs  (Read 4560 times)

Offline bigben

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Glacier N.P. TERs
« on: May 29, 2007, 02:47:30 AM »
I'm in the process of updating my DEM data so if download time is a problem for you then I suggest waiting a bit.  I'm going to replace as much SRTM data as my RAM will allow with 1/3" NED from USGS. I'll also release a set of images for use in creating additional masks for each of my terrain sets.
  • GlobalMapper Slope shader (for lakes and rivers)
  • NLCD 2001 Landcover
  • NLCD 2001 Canopy

The last two look really useful for creating masks for different vegetation cover (esp. farms) and tree distributions and are indexed colour :)

Here's a second set of TERs. Only 5 coverage this time (I forgot to check how wide I made the Grand Canyon terrains) but it's still plenty of padding around the central area of 10m DEMs. I've done plenty of renders around this area in TG0.9 so I can certainly appreciate just how much of an improvement you can get with TG2 using this method.

InnerOuter
4238-04240-1

Terrains: http://www.path.unimelb.edu.au/~bernardk/terragen/files/bb_glacier_composite.exe 71Mb, self-extracting RAR
Slope map: http://www.path.unimelb.edu.au/~bernardk/terragen/files/bb_glacier_composite_slope_map.exe 43Mb, self-extracting RAR

The slope map is a 10,000x10,000 pixel greyscale image using GlobalMapper's slope shader. I find this really useful for selecting lakes. With DEM data they're white and if surrounded by even the faintest of grey it's enough to use the magic wand in Photoshop to quickly select them... and there's a lot of lakes here. It also makes drawing rivers manually easier, as you can usually see when you're going up the side of a bank.

4242-2

There's a clip file with the slope map to correctly size any images derived from it. The slope map only covers the middle 3 TERs as I normally only render around the middle and extending it further makes the image too big or cuts down the resolution.
« Last Edit: May 30, 2007, 05:21:51 AM by bigben »

Offline dhavalmistry

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Re: Glacier N.P. TERs
« Reply #1 on: May 29, 2007, 04:00:58 PM »
WOW!! thanx
"His blood-terragen level is 99.99%...he is definitely drunk on Terragen!"

Offline bigben

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Re: Glacier N.P. TERs
« Reply #2 on: May 29, 2007, 09:33:40 PM »
You're welcome.

For those using the slope map for generating lakes:
  • If you're using Photoshop's magic wand to select the lakes, set the tolerance to 1 and turn OFF antialiasing.
  • It pays to resize your mask down to between 5000 - 8000 pixels wide. At 10,000 you can run into RAM issues too quickly. Alternatively you could reduce the canvas size by 50% and use it as is (also reducing the width in TG by 50%). The outer region contains a lot of SRTM data which isn't as useful.
  • Saving with LZW compression reduces the file size a lot (not to be confused with TG's RAM usage as it still has to decompress the image to render it). My test map of 6,000 pixels wide is only 232kb

It's been ages since I logged on to Geocommunity and I found you now need a Premium account to download data. I'll try and update my data from USGS seamless to improve these TERs at a later date.
« Last Edit: May 29, 2007, 09:37:06 PM by bigben »

Offline bigben

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Re: Glacier N.P. TERs
« Reply #3 on: May 29, 2007, 10:32:07 PM »
OK I'm getting some odd scaling effects on this so you may want to wait before downloading while I check things out.

Offline bigben

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Re: Glacier N.P. TERs
« Reply #4 on: May 30, 2007, 05:14:00 AM »
I'm in the process of updating my DEM data so if download time is a problem for you then I suggest waiting a bit.  I'm going to replace as much SRTM data as my RAM will allow with 1/3" NED from USGS. I'll also release a set of images for use in creating additional masks for each of my terrain sets.
  • GlobalMapper Slope shader (for lakes and rivers)
  • NLCD 2001 Landcover
  • NLCD 2001 Canopy

The last two look really useful for creating masks for different vegetation cover (esp. farms) and tree distributions and are indexed colour :)
« Last Edit: May 30, 2007, 05:22:16 AM by bigben »

Offline rcallicotte

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Re: Glacier N.P. TERs
« Reply #5 on: June 03, 2007, 01:36:15 PM »
Thank you!
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