Hi, I have a project where LiDAR data has been supplied with file types RRD, ERS, AUX, TFW, TAB and TIF. No LAS files were supplied (or available apparently) and I'm having trouble finding out how I generated a point cloud/surface from these files.
The TIF image appears to simply be a greyscale version of a normal vertical aerial photography.
The TAB file does not open in Civil3D, but will in MapInfo. The image that appears shows an oblique view of the landscape. So there is elevation information there, but for that image it is nothing like georeferenced.
The RRD file is a large file (similar in size to the TIF) and I suspect that is where the real data lie.
Does anyone have any clues as to how to utilise these files?
thanks Jon, I'm pretty sure I tried the GeoTIFF option... can't remember the outcome exactly so will try again and explore any options. [update. I tried it again 'Create surface from DEM' then GeoTIFF... C3D just says 'unable to read file'. I tried also creating a point cloud and reading data from the TIF file - I've tried with and without setting a coordinate system, but in all cases, C3D starts to create the point cloud and then I get an error: 'an error occurred in data processing'. I've tried multiple files (tiles) from the LiDAR set. ]
Yes, I got the impression that the dataset had a number of files to improve compatibility (mapinfo, arcview, etc.) which makes it all the more frustrating that I can't seem find something to open it all correctly. I don't have any ESRI products to turn to.
I did run into a circumstance before where the GEOTIFF was unable to be understood by Civil 3D due to its compression format (LZW or something similar). If you have a program you could open the file with then save it with different or no compression Civil 3D may be able to read it, Gimp should be able to handle a file that size and is free.
Thanks Jon, I don't think I'll be able to upload due to licencing issues. File sizes are massive too.
As it turns out, after about 15 phone calls today, it seems that the LAS files may be available after all and should be sent to me today. So if all goes well, I can just do things as I normally would. I submitted this thread to Autodesk support as well, so it will be interesting to see if a solution to the original problem is available.
I'll post the outcome
If you have a program you could open the file with then save it with different or no compression Civil 3D may be able to read it ... Gimp
I'd not do that, sir.
If you resave a Geotiff file in a third-party editor, you'll lose the geo-header embedded within the Dem, no matter of the external TFW worldfile.
To recover the point cloud in a text fashion, I advise to convert the Dem file to XYZ Ascii format, e.g. thru the free Microdem.
Well, I've got hold of the 'not available' LAS files and as expected they provide everything I need. So my project issues are solved.
As for my original post - I spent another half hour just to see if any of the other suggestions raised here would bear fruit, but no real luck on that front. I can't spend any more time on it - too many deadlines, so I'll have to let the next user who comes up with this issue to carry on the quest.
Thanks Jon and Antonio for your suggestions.
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