Export Geotiff to other programs

mash

Hi, Source data is USGS 3DEP. I'm trying to export a Geotiff image to use as a Height map in World creator 2 or Gaea. In both programs when I import the file as a Heightmap I get a stair stepping effect. Like the file has gone from 32 bit to 16 bit. I'm trying to figure out of the issue is with Global mapper export or if it's a problem with the import in WC2 or Gaea. If anyone has any ideas I would appreciate it. Thank you 

bmg_bob

Hello,

When you export the elevation grid as GeoTIFF, be sure to select the "Elevation (32 bit floating point samples" option. If you prefer an integer format, change the Vertical Units to centimeters or millimeters or inches.

Cheers,
Bob

mash

Thanks for the answer, For some reason that option is greyed out for me. 

bmg_bob

Hello,

It appears that you are exporting your data as a raster image instead of an elevation grid. Use File | Export | Export Elevation Grid Format, then select GeoTIFF from the list. You should get options that have the Elevation file types enabled.

Cheers,
Bob

SuenosPanoramicos

Hello. I'm new here, and having the same problem. Now exporting as Elevation Grid Format (thank you Bob), but it is showing up terraced. The original file is nice and smooth, but enormous, so all I am doing is exporting a smaller section.

I'm importing it into Unreal using Terrain Magic.

bmg_mike

What is likely happening is that your elevation values are snapping to the nearest whole number value in the selected units. If you choose the 32-bit floating point samples option on the GeoTIFF export dialog, then you should get the full resolution, although the file will be much larger than the 16-bit elevation sample option.

If you must use the 16-bit option, choose a more precise elevation unit, like centimeters, to eliminate the stairstep (or at least make the steps one centimeter in size, which is likely more precise than your actual data).

Thanks,

Mike

DerrickW

Here's a screenshot of the dialogue & option that Mike is recommending you use.

16 bit integer / 32 bit integer samples is causing the terracing effect because it'll round all of your elevations to the nearest whole number. "floating" (decimal) points support elevations with decimals.

32-bit floating point export:

16-bit integer export: