Google Maps -> Terrain Height Map?

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bigbman
Posts: 23
Joined: Thu Nov 04, 2010 6:35 am

Google Maps -> Terrain Height Map?

Post by bigbman »

Wondering if anyone has experimented with converting real-world map data to a height map. The most compelling strategy I've seen thus far involves importing Google Earth maps from SketchUp Pro, exporting to 3ds, then... I'm guessing there's a plugin that can convert the geometry to a heightmap.

Seems pretty messy and I'm rather pessimistic about the final quality/accuracy of the heightmap.

Please share any techniques that have worked for you!

Thanks!
Radikalizm
Posts: 1215
Joined: Tue Jan 09, 2007 7:03 pm
Location: Leuven, Belgium

Re: Google Maps -> Terrain Height Map?

Post by Radikalizm »

Quality completely depends on the amount of samples you would take from your mesh to generate your heightmap, you can make it as accurate as you want

I'd try to get hold of actual elevation data instead of going through all these steps to generate your heightmap, seems much more straightforward and shouldn't be all too impossible I think
bigbman
Posts: 23
Joined: Thu Nov 04, 2010 6:35 am

Re: Google Maps -> Terrain Height Map?

Post by bigbman »

and how would I do that? Sorry, I'm in the dark as to which formats or tools can provide this.
ACE247
Posts: 704
Joined: Tue Mar 16, 2010 12:31 am

Re: Google Maps -> Terrain Height Map?

Post by ACE247 »

I've been working with this for a while already, however it is a rather complicated process and involves a lot of pro tools. I've been using Google Earth, USGS Seamless data, Global Mapper and L3DT to accomplish the task. Depending on how many of you guys show an interest in this I might write up a full tutorial on getting near 1:1 3d terrain. It's going to take me a while though since I'm quite busy and the process is quite lengthy. However for a simple messy version you can download heightmap data from USGS Seamlesshttp://seamless.usgs.gov/website/seamless/viewer.htm in a suitable format and convert it to mesh or heightmap with Terragen or one of the many other viewers. The accuracy isn't great for non-american countries (about 90m/pixel) however if you wan't US data you can get up to 3m/pixel. There's a lot of tutorials about that on the web. Also be sure to save your heightmap's with one 8bit color indexed channel only for just loading with the heightmap node. The Terrain mesh loader though can be adapted to handle more.
bigbman
Posts: 23
Joined: Thu Nov 04, 2010 6:35 am

Re: Google Maps -> Terrain Height Map?

Post by bigbman »

Cool link! I would love more info if you have the time!
gerdb
Posts: 194
Joined: Wed Dec 02, 2009 8:21 pm
Location: Dresden, Germany

Re: Google Maps -> Terrain Height Map?

Post by gerdb »

hi,

to store Heighmap-data with more than 256 values you should use ECOLOR_FORMAT: R32

so one channel with 32 bits. if you have geometric data (voronoi triangulation) it is difficult to transform to a rasterimage, because of the equal pixel distance.

For Germany there are DGM100 DGM30 etc (deutsches Geländemodell), for Berlin there are exact (1m) DGM1 maps, but in extraordinary formats

i downloaded some earth maps over 1 GByte from Nasa and played with them, but are 8bit, so not exact anyway.
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