3DEM - Free Geography Tools

Archive for the '3DEM' Category

Create KML Range Circles, Arrows And Wedges With An Excel Macro

Published by

at November 19, 2009 in 3DEM and blogkeeping. 0 Comments

I’m currently running OpenOffice only, so I can’t try it out, but “Planeman” has created an Excel macro that will create range circles, arrows and wedges for a list of decimal latitude/longitude points. Should be able to create these for hundreds or even thousands of points simultaneously. Pictures are from Planeman’s description. Excel spreadsheet view:

mvsppi

And a view of the results from the sample data in Google Earth:

23wqxhc

Download the spreadsheet macro at this link; be sure to scroll down to the bottom to get the latest version. From the picture above, looks like additional features are coming soon.

kmlfactbook – The CIA World Factbook In Google Earth Format

Published by

Leszek Pawlowicz

at November 18, 2009 in 3DEM, blogkeeping and geocoding. 0 Comments

The CIA World Factbook …

provides information on the history, people, government, economy, geography, communications, transportation, military, and transnational issues for 266 world entities. Our Reference tab includes: maps of the major world regions, as well as Flags of the World, a Physical Map of the World, a Political Map of the World, and a Standard Time Zones of the World map.

In short, it’s the go-to source for current world demographic, economic, social and political data. David Tryse has taken data from the Factbook and created an online application, the kmlfactbook, that generates thematic maps in KML format for use with Google Earth. Select a dataset:

factdataset

Then choose a chart type, coloring scheme and other options:

charttype

2D charts are flat choropleths:

2dchoro

3D add scaling based on height:

3dchoro

And “Chart” creates a pie chart:

piechart

There’s a Google Earth plugin view that lets you preview the appearance, and when you’re happy, you can export a KMZ file. And you’re not limited to CIA World Factbook data; if you register on the site, you can upload your own data to convert it to a thematic KMZ file.

The one thing that seems to be missing is the ability to create a map legend to show what the color codes represent (or at least I couldn’t find it); you can click on placemark icons on each country to get the data, but it’s not the same. Hopefully, legends will be added soon.

Via Google Earth Blog.

3DEM Website Is Gone, But 3DEM Still Available Here

Published by

Leszek Pawlowicz

at June 9, 2009 in 3DEM and DEM. 16 Comments

I’ve covered the program 3DEM before on this blog; it’s a first-rate 3D terrain visualization program, and does the best out-of-the-box map relief shading of any free program I know. Here’s a standard USGS topo shaded with a digital elevation model using this program:

toporeliefshaded

Unfortunately, the author, Richard Horne, has ceased development of the program, and shut down the website permanently. But he’s graciously given me permission to host the last version of the program (version 20.4) here on Free Geography Tools; you can download it here. It comes with a full PDF manual, and my posts may offer additional insight on using it. I can offer some limited help if you run into problems, but any bugs in the software are there to stay.

Free Landscape Rendering Software

Published by

Leszek Pawlowicz

at June 22, 2007 in 3DEM and DEM. 2 Comments

Download Squad posts that Bryce 5.5, a program that creates photo-realistic landscape renderings and animation with vegetation and realistic skies, is available as a free download (registration required to get a free serial number). While it lets you create your own topography, it also accepts DEMs as input for the landscapes. This is one version below the current 6.1 release, but is still feature-rich. Unfortunately, it also has a very idiosyncratic interface that takes a lot of getting used to. Here’s a review of the program from PC Pro, with some screen shots.

There are other free programs for realistic landscape rendering, with some limitations compared to Bryce 5.5 but also somewhat easier interfaces to navigate:

Genesis IV: Available in a freeware edition for personal use, as well as several paid versions.

Terragen: The free non-commercial version limits the output resolution. There’s also a Technology Preview release of Version 2.0 available as well, though it has a fairly technical interface.

The free program 3DEM can convert a number of DEM formats to Terragen’s native terrain format, and to formats compatible with Genesis IV.

Elevation, Slope, Terrain And 3D Anaglyph Map Shading In MicroDEM

Published by

Leszek Pawlowicz

at May 18, 2007 in 3DEM, DEM, MicroDEM and cartography. 0 Comments

For general map relief shading, my first choice is usually 3DEM, since it usually gives the best results. But MicroDEM also does a decent job at terrain relief shading, and has a few other shading options that 3DEM lacks.

Continue reading ‘Elevation, Slope, Terrain And 3D Anaglyph Map Shading In MicroDEM’

Animated Flooding Maps – Storm Surge, Sea Level Rise And River Flooding

Published by

Leszek Pawlowicz

at May 11, 2007 in 3DEM, DEM, MicroDEM and global warming. 6 Comments

A while back, I did a post on assessing the effects of sea level rise on coastlines using the program 3DEM. Here’s a terrain image of southern Manhattan Island at current sea level:

manhattan

And here’s what it would look like with 8 meters of flooding, due either to a hurricane storm surge or global-warming-induced sea level rise:

Manhattan flooded by eight meter sea level rise

The problem with the latter image is that 3DEM did a basin flood, i.e. it filled in all the terrain that was less than 8 meters below sea level, without taking topography into account. For example, a range of hills could lie between some lowlands and the sea, but 3DEM wouldn’t take that natural dam into account. But I also posted an animated flooding map of the same area that did take that terrain blocking into account (click on the “play” button to view the animation):

Today’s post will show how to create such a flooding animation.

Continue reading ‘Animated Flooding Maps – Storm Surge, Sea Level Rise And River Flooding’

Modifying The Terrain Reflectance Display In MicroDEM

Published by

Leszek Pawlowicz

at April 27, 2007 in 3DEM, DEM and MicroDEM. 0 Comments

Yesterday’s post dealt with the basics of installing MicroDEM, and opening up DEM terrain files in the program. Now it’s time to look at different ways to display terrain reflectance in DEM. While 3DEM is better for some kinds of displays, MicroDEM has more different ways to display reflectance.

Continue reading ‘Modifying The Terrain Reflectance Display In MicroDEM’