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Archive for the '3DEM' Category

Free Landscape Rendering Software

Published 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 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 at May 11, 2007 in 3DEM, DEM, MicroDEM and global warming. 4 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:

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 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’



Recap Of 3DEM Series

Published at April 15, 2007 in 3DEM. 1 Comment

A brief summary, with pictures, of all the posts in my 3DEM series.

DEM Terrain Depiction Using 3DEM

Visualizing digital elevation model (DEM) data as colored, shaded terrain.

Easy Map Relief Shading Using 3DEM

Combining DEM data with a flat map, to convert this:

to this:

Sea Level Rise, Storm Surge, And Flooding Effects Using 3DEM

Using 3DEM to show the effects of sea level rise on the coastline. For Manhattan today:

a rise in sea level of 8 meters due to storm flooding or sea level rise will result in this new coastline:

3D Perspective Views With 3DEM

Overlaying maps or photos on top of terrain with 3DEM to create either static perspective views:

or animated rotating perspectives:

VRML Worlds Using 3DEM

How to create interactive, 3D VRML worlds for terrain, with or without map/photo overlays:

GPS Track Elevation Profiles With 3DEM

Generating a terrain profile from a GPS track:

Animated Flybys Using 3DEM

Creating an animated flyover of terrain, with or without map/photo overlays:




Animated Flybys Using 3DEM

Published at April 8, 2007 in 3DEM, DEM and Google Earth. 0 Comments

There’s one last feature in 3DEM I want to talk about: the ability to create animated fly-bys over terrain, with or without an image overlay. Doing a comparable animation with Google Earth requires either the expensive Pro version, or a copy of FRAPS for $37. While 3DEM’s animations aren’t as fancy as the ones you can get with Google Earth, they’re pretty good.

Continue reading ‘Animated Flybys Using 3DEM’



GPS Track Elevation Profiles With 3DEM

Published at April 5, 2007 in 3DEM, DEM, GPS and GPX. 1 Comment

3DEM ostensibly comes with a number of GPS interface capabilities, including the ability to download waypoints, routes, and tracks, and upload waypoints created in the program. I say ostensibly because I could only get one of the features to work with my Garmin 60Cx, downloading tracks; maybe you might be able to get more to work with your GPS model. But even that one feature allows you to do something more than just display the track on top of a terrain image: it lets you see the elevation profile for the entire track.

Continue reading ‘GPS Track Elevation Profiles With 3DEM’



VRML Worlds Using 3DEM

Published at April 4, 2007 in 3DEM and DEM. 0 Comments

At one time, Virtual Reality Markup Language (VRML) was going to be the next big thing on the Web; fully-interactive 3D environments were going to change the way we interacted with the Internet, and our computers. Didn’t quite work out that way - most people were on dial-up back then, which was too slow to make VRML practical. Even after broadband became more prevalent, it turned out that most people didn’t really want to interact with their computers that way. For displaying maps in an interactive 3D environment, Google Earth, World Wind, and other similar programs have pretty much supplanted VRML. But there may still be a place for it in some applications: you can use higher-resolution terrain than what’s currently available in Google Earth/WorldWind along with your own image overlays, the computing requirements are reduced, and the filesize for VRML worlds is usually pretty small. And you can get both stand-alone VRML viewers and browser plug-ins for multiple platforms for free.

3DEM makes creating a VRML world easy. From yesterday’s post, if you’re in a “Foreground” terrain view:

Select choose File=> Save VRML World; a file save dialog will open asking where you want to save the files. Next, you’ll be asked to specify some additional parameters for your VRML world:

Surface Smoothness and World Dimension set the effective resolution for your VRML world. Flat is less detailed than Smooth, and creates a smaller file size, but given the speed of modern computers, there’s little reason not to set Surface Smoothness and World Dimension to their maximum. Click OK, and two files will be created: an *.wrl file, which contains the terrain data, and a *.jpg file that contains the image data that overlays the terrain. You’ll need to keep both files together in the same folder when viewing the VRML world

To view the result, you’ll need a VRML viewer. Here’s a screenshot from GLView:

Using the controls in this program, I can walk or fly around the terrain, zoom in and out, change my viewing angle and altitude, take snapshots, and so on.

GLView is the best VRML viewer I’ve seen, but unfortunately it’s no longer available for public distribution. But there’s a good VRML browser plug-in called Cortona available for free from Parallel Graphics. There’s also a stand-alone VRML viewer available from Octaga, but I haven’t actually tried that one myself.



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