topic Re: tracking elevations from a tiff in AutoCAD Map 3D Forum

tracking elevations from a tiff

MKH-VB — Wed, 28 Jan 2015 15:50:54 GMT

was able to connect a geo-tiff to my map. Can someone tell me how to "track" elevations? Just want to display or list the elevations as I move the cursor. Thanks

Re: tracking elevations from a tiff

Alfred.NESWADBA — Thu, 29 Jan 2015 05:46:23 GMT

Hi,

there is no objectsnap, even no geometry you have when displaying a raster-dem like model. So there is also no option to get the elevation at specific points directly.

What you can do: you can create contour lines from your tiff, these are stored into a SDF, that will give you geometry and so you can get elevations from that contours/points on contours.

HTH, - alfred -

Re: tracking elevations from a tiff

antoniovinci — Thu, 29 Jan 2015 07:07:27 GMT

I too fear there's no way to get that in Autocad, while it's automatic in a free software like Qgis, sir.

Re: tracking elevations from a tiff

MKH-VB — Thu, 29 Jan 2015 14:45:15 GMT

how do i create contours in autocad map from the image?

Thanks

Re: tracking elevations from a tiff

braudpat — Thu, 29 Jan 2015 15:14:26 GMT

Hello from France

With ACAD MAP (since Release 2008 maybe 2007) you can create elevation contour from ESRI Raster Elevation files : .ASC files in fact

Sorry I don't know if it's possible also from GeoTiff !?

Here a nice french tutorial to generate elevation contour from ESRI .ASC files :

http://geospatialfrance.typepad.com/geospatialfrance/2007/09/convertir-un-mn.html

I hope you can follow the tutorial even if you are not French !?

Re: tracking elevations from a tiff

Alfred.NESWADBA — Thu, 29 Jan 2015 15:20:09 GMT

Hi,

>> how do i create contours in autocad map from the image?

In the task pane of Map 3D (command _MAPESPACE) right-click your DEM layer ==> there you find the option to create a contour layer.

- alfred -

Re: tracking elevations from a tiff

braudpat — Thu, 29 Jan 2015 15:25:27 GMT

Hello Alfred

YES I am a "poor stupid" boy !

I am using often this feature (since a long time ago) but only with ESRI .ASC Files !!

And the french tutorial says >>>

En résultat, vous obtenez l'affichage de votre MNT.

Ce MNT peut être dans les formats GeoTIFF, Esri Grid Ascii (extension .asc), Esri Grid Binaire <<<

Thanks to open my eyes !!

Re: tracking elevations from a tiff

MKH-VB — Thu, 29 Jan 2015 17:00:34 GMT

Thanks very much....I have the contours created which brings another issue.....how could I raise that DEM by a multiplication factor of 3.28. I need to do this because the image is in meters, and I need US feet. Thanks. MKH

Re: tracking elevations from a tiff

Alfred.NESWADBA — Thu, 29 Jan 2015 19:21:42 GMT

Hi,

>> how could I raise that DEM by a multiplication factor of 3.28

I created a video that shows how to create contours from DEM and as a second step how to scale the elevation of the contours.

Let me know if you have additional questions to that.

>>>video on youtube<<<

HTH, - alfred -

Re: tracking elevations from a tiff

MKH-VB — Thu, 29 Jan 2015 19:31:28 GMT

awesome. I appreciate the step by step!