Skilifts.org / SORT Forum

As stated in another thread, I use several freeware programs to help visualize ski resorts. Here is a quick review of what I do:

For overhead images and measuring acreage, lift lengths and distances, I use DLGV32 Pro (AKA Global Mapper). You can load DEMs (Digital Elevation Maps) that render an overhead 3D look (casting shadows). You can overlay a DLG (Dogital Line Graph) thats basically digitalized topo map or a DOQ (Digital Ortho Quad) thats bsically a B&W image ontop of the 3D relief and get really cool results:

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You can get DEMs from various sites (USGS, Goecomm, etc. - search Google). This first step is loading the DEM. DLGV32 can load just about any DEM format straight from the internet. Once loaded, it will look like this:

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Then you load an overlay. You can use DLGs or DOQs (or images downloaded from Terraserver...more on that later). When you download DOQs or DLGs, make sure you also download the metadata file that goes with it. For instance, the Crystal Mountain DLG file is named o46121h4.tif. You also need to download a file named o46121h4.tfw, which has the longitude and latitude coordinates. DLGV32 automatically reads the metadata file when you load the DLG file into it, if its in the same directory. Otherwise you get a dialog that wants you to manally add longitude and latitide coordinates, whcih is a pain. Once loaded you get this:

Oops, the picture is here:

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Now the topo is overlaying the DEM, but it is opaque. You can change that by going to Tools...Control Center and selecting the DLG overlay(s), and pressing the Options button. Select the Texture Map option and close. You can also tweak the transparancy by playing with the Blend and Translucency features. You should then get the first image I posted.

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You can also lay down lift lines and area boundaries by working with the Digitizer Tools (patience required - it is difficult to work with), as seen here in a DOQ overlay. I have to work now, so I will post info on generating 3D images through 3DEM later.

To image a resort in 3D, I use 3DEM (freeware). Again you have to load a DEM file first, then load the image map (DOQ or DLG). This program also requires that you have the metadata (long/lat) info in a separtate file to load. I found that loading DOQ files is also incredibly slow because they are too large, and 3DEM has to downsample. What works better is to use DLGV32 to load the DEM & image file, then select a smaller area and export as a .jpg. DLGV32 automatically creates the metafile with the export, so you can load it into 3DEM automatically. You may have to play with sample size and your selected are to optimize the export. Also, turn off the 3D shader texture map so that the shadows are not exported as an image (3DEM will create a better shaging anyway). Here is what 3DEM looks like with the DEM and an image overlayed (top view):

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The 3D view window creates the following image:

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You can zoom in and get pretty good detail on things by adjusting the 3D view window:

The last thing to note is that partial DOQ images can be had at terraserver.microsoft.com. The only problem is that you have to enter the latitude and longitude values by hand. You first select something you want to download, then hit the info button at the top of the page, and it will give you lat/long values. Take 2 corners (ex: 39.65465, -106.42674) and input that into one coordinate. Then you take the oposite corner and input that into the second coordinate. This works in both DLGV32 and 3DEM by the way.

That is really cool, how long does it take to make one of those?

That is awesome which resorts have you done so far?

That turns out VERY cool.
Since you already have the tools and some practice, would you be willing to do another resort up?

Interested in one of Hyak/Central/West ( from 618167E 5254148N to 621489E 5252796N )

And one for Alpental (from 616016E 5256719N to 619613E 5253854N )

Yes Alpental would be a great one to see although the back side would be a little tricky I think but hey what do I know?

Thanks for writing this all up Powdr, but I'm still having problems. The problems I'm having is actually getting the DEM map and getting it to work. I visited the USGS site and when I wanted to search for a DEM map, it lists other websites like Terraserver, mapmart and some others to find a DEM map. Mappart.com was the only place I could find a DEM map, but I couldn't save it or get any other info about it unless I bought it. When I try to search for DEM maps, I'm getting video game sites. Could you please give me a link to the USGS site to getting a DEM. I think that might help me out. Once I get my feet off the ground, I should be able to get this to work.

Thanks again.

SkiBachelor,

Here is the link to free DEMs:

http://data.geocomm.com/

You have to sign up for a free account, and other items DLGs & DOQs are not free, but DEMs are. It is also a pretty slow connection.

You can also get other free stuff from links at this site:

http://www.collinsso...by_type.htm#DRG

I get Utah and CA DOQs/DEMs from there.

Powdr

General reply to all:

- The entire process takes as little as half an hour if you get the right data files.

- I have done Jackson Hole, Killington, Park City, The Canyons, Squaw Valley, Heavenly, Crystal Mountain, Parts of Mt. Hood and a few other test runs.

- I will make the Alpental/Snoqualmie areas in the next day or so.

- I will do requests, but it may take some time, as I have a real job too!

Powdr

Could you post the one on Killington?

Can you post the ones from Crystal Mountain? I would be interested in seeing that.

crazyskier91, on May 26 2004, 04:05 PM, said:

Here is a simple 3D of Killington. I can add lifts (runs too, but that would take time!), change the angle, zoom in etc. Let me know what you are looking for. I can also increase the image size all the way up to 4000x3000, which is about 2.3 MB, allowable on this site.

Powdr