Export Elevation / Web Format - VRML / Resample Elevation Grid

codemouse

Mike,

I'm exporting elevation data (from DEM files) into VRML and therefore they contain an Elevation Grid. Is there any way for me to resample that elevation grid (namely, to downsample) prior to export via Global Mapper?

Brian

global_mapper

Brian,

The down-sampling will occur automatically based on the export bounds and pixel dimensions that you provide to the export call. By default an appropriate resampling method (GM_SamplingMethod_t8) will be selected based on how much you are resampling, but you can specify an explicit resampling method to use by calling GM_SetRasterDisplayOptions (call GM_GetRasterDisplayOptions to get first) to set a specific mSamplingMethod to use.

Thanks,

Mike
Global Mapper Guru
gmsupport@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

codemouse

Thanks Mike, this works great - it looks like the default mSamplingMethod is set to GM_SAMPLING_BILINEAR_INTERPOLATION.

Future request - perhaps a GM_SetRasterDisplayOptionsEx to include aLayerList (set multiple layers all at once with the same info?). Probably wouldn't make much sense on the Get side of things, as each layer could potentially be different (best to spin through them).

Brian

DallyDemelza

I really enjoyed reading this post. I congratulate you for the terrific job you've made. Great stuff, just simply amazing!