hi all, i am a newbee to handling drone ortho data. i was able to figureout to use pix4d for my processing. i have taken up a client pilot project for survey. however when i have delivered then the dtm output i have from pix4d output, he sent me a reference dwg format of a survey traditionally done with total station. i am not very well versed with gis things. i am not able to figure out how to convert the pix4d dtm output to the desired format.
* link one is the pix4d DTM output that i have generated from drone data
i would really appreciate any help in this regard.
Ps: i was not able to figure out where this query has to be posted. please guide me where to post regarding this issue, if this is not the place to be.
Cheers n Regards
He's using AutoDesk, put the same photos in ReCap 360. Otherwise you can save it in an LAS file that he can open in AutoCad & the contours should be there.
As stated by someone else, you can get the contours and the points directly out of the Pix4D software.
The linework around the features would be easy to extract using the image and drawing over it either in a CAD or GIS software.
for the grid dsm (5cm spacing is really dense so it can do really big files). i don't know what is the area covered by your dtm, but with high density mapping with a total station it should be more something like 5m spacing.
But again from pix4d : https://support.pix4d.com/hc/en-us/articles/202558419
the grid dsm option will write a file with xyz at a regular spacing, and the XYZ format is a standard ascii file.
And to generate the contour lines, in the same page, you'll have to choose autocad dxf and set the resolution and the interval of your contour.
Once it's done, in the process menu clic generate contour lines.
Then you'll have all the data you need.
To import the xyz data you'll have to use a lisp if you don't have access to autocad map or autocad civil.
Sounds like you want to convert your tif DTM file into 3D points with a 5x5cm spacing, is that correct?
To generate contour lines with pix4d you can use the "additionnal output" option in the dsm/orthomosaic output menu. and choose the autocad dxf option.
To write the elevation every 5m in the autocad drawing is a little bit more tricky.But the way i would do it, is to export the grid dsm with 5m spacing in xyz file then import it as text in the autocad drawing.
Contour lines marking and the other things that are in the drawing are editing.
Hope it helps
Alright, I've messaged you and you can send me a link to the uploaded file with the methods I suggested.
To do this without buying any programs you'll need a few things:
DWG to DXF Converter: http://www.opendesign.com/guestfiles/TeighaFileConverter
Quantum GIS: http://www.qgis.org/en/site/
And a guide: http://www.digital-geography.com/qgis-tutorial-i-how-to-georeferenc..., This one is very basic, but there are many others out there. You are looking to 'Geo-reference a TIF to a DXF with QGIS'. Search for that and you'll find many examples
QGIS only supports DXF files, so you'll need to get the DWG into a DXF. AutoCAD supports both very well, so it might be simplest to get your client to give you a DXF instead of a DWG. If you can't do that then use the converter I linked above.
Bring the DXF into QGIS (it has to be into a blank project, and it has to be first, before the TIF). Using whatever guide you find, you need to line the TIF up with the DXF using features that you can find in both. The tool you'll need is in the menu, Raster -> GeoReferencer.
After you have the TIF lined up properly (georeferenced), you can convert it to Contours using Raster -> Extraction -> Contour... The resulting contours can be saved as a DXF. If you give that to the Client along with the Georeferenced TIF, then it might be enough.
Give that a try and see if it works for you.
Is this something you want to know how to do, or have done for you?
I am guessing that by 'reference' you are talking about the coordinate system the data is in? Do you know the name, factory code, 'well-known-id' (wkid), or 'spatial-reference-identifier' (srid) of the coordinate system your client wants the data in? I don't think DWGs have that data in them normally, unless it's the most recent version of AutoCAD you're using. The client might have it annotated on the DWG, but the viewer you linked doesn't seem to show annotation...
To set the coordinate system of our output in Pix4d, read this:
What exactly are you looking for?
I converted your tif to contours (see attached).