Importing GeoTIFFs.

[l.a. akira]

Im planning on starting a tg2 project quite soon using dem data from seamless.usgs.gov and was wondering how I can go about converting the size of the GeoTIFF to display accurately in terragen. I've only used geoTIFFs with TG2 once or twice for testing purposes and noticed they come in completely off scale.

[bigben]

You could convert them to TER. I haven't used Terraconv for this but it may be of some help.  http://koti.mbnet.fi/pkl/tg/TerraConv.htm

The page says that it reads the scaling from GEOTIFF but I'm not sure if it handles non-standard image sizes (images not 2ⁿ+1 pixels square) I'll give it a try tonight and let you know if no one else answers.

3DEM will also do it, but I'm not sure what it's maximum TER size is with the current version.  I've been using GlobalMapper to do this.

[l.a. akira]

i've been using 3dem for this but the GeoTIFFS from usgs.gov come in the wrong size.

[Oshyan]

Terragen 2 doesn't support GeoTIFF metadata so if anything it will only be able to read the normal TIFF image data and as such the scaling would have to be applied manually. You would need to derive the proper scaling info from another application which can read it.

We do intend to support more DEM formats in the future, along with basic georeferencing, etc. However this support is a ways off at this point.

If you will be working with GeoTIFFs and other DEM or GIS data frequently and/or it is for a commercial project I highly recommend purchasing a copy of Global Mapper. It supports the widest format of raster and vector GIS data types for both import and export of any application I'm aware of, much less at its price level (about $280). It's admittedly a little pricey if you're just using it as a converter, but its power and flexibility are well worth it for anyone working seriusly with GIS data.

- Oshyan

[l.a. akira]

So lets say I did pick up global mapper, what would be the ideal format I should convert the file into for TG2? Also, is there anything special I would need to do during the conversion process? I'm asking ahead of time as i've never used global mapper before.

[bigben]

Global mapper supports exporting of Terragen terrains (.TER)

I also use it for creating images to base my masks on, mainly landsat image overlays and a slope map.  It's very versatile in mixing data formats as well e.g. 10m DEM, 90m SRTM, ascii bathymetry etc...

I only have an old version (it was cheaper) that is limited to exporting 2049x2049 terrains, but the new version is much better.

[Oshyan]

Convert to .ter. Global Mapper should make it pretty easy to maintain the scale info when doing so. I would go for a native size, unresampled .ter export (not one of the preset sizes, 513x513, 1025x1025, etc.). When you bring it into TG the scaling should automatically be right. If you have multiple GeoTIFF's or other DEM's Global Mapper is excellent at stitching them all together for export as one big .ter. If you have more specific Global Mapper questions they have a discussion list as well and are also very responsive to support and pre-sales queries.

- Oshyan

[dhavalmistry]

you will have to convert to DEM first and then using 3DEM (freeware) you can convert DEM to TER file which can be imported by TG2