Whatever works for you - although I can sense the purists going cross-eyed at the phrase "using Geojson as our internal coordinate system " :) I think you might be piling up problems for your self later - but then I don't know your scope.
Good luck. PS - just to be clear "purist" is not meant to be in any way pejorative. On Wed, 2 Dec 2020 at 20:57, Brandon Biggs <[email protected]> wrote: > Hello, > We're using JavaScript, not Unity, but this is very interesting, I wish it > was a JS package. > We're kind of using Geojson as our internal coordinate system at the > moment, but with a few oddities, like allowing 0.0 as the origin, rather > than using Long lat. > I just built a parser, so we're good. > Thanks, > > > Brandon Biggs <https://www.ski.org/users/brandon-biggs> > Engineer > > Smith-Kettlewell Eye Research Institute > Office: 415-345-2130 > Cell: 650-833-9394 > > ------------------------------ > *From:* Paul Harwood <[email protected]> > *Sent:* Wednesday, December 2, 2020 12:20 PM > *To:* Brandon Biggs <[email protected]> > *Cc:* Andrew C Aitchison <[email protected]>; > [email protected] <[email protected]> > *Subject:* Re: [gdal-dev] Converting OBJ to Geojson files with ogr2ogr > > GeoJSON is very good for many things but I would not convert an .OBJ to > GeoJSON and then into the VR space local coordinate system. You are going > to have project the OBJ into 4326 and then project it again into the local > coordinate system - even if implicitly. Go directly from OBJ to an internal > mesh. > > If you are building the VR in Unity - you can use this to do it : > > https://openupm.com/packages/com.virgis.geometry3sharp/ > > You really should take a look at what we are doing at www.virgis.org - we > have worked a lot of this out. It is in Unity but even if you are not using > Unity there could be good learnings. > > > > > > On Wed, 2 Dec 2020 at 16:02, Brandon Biggs <[email protected]> wrote: > > Hello, > It's for a custom coordinate system for VR. Geojson provides a very easy > syntax for properties and geometries that I like to use with origin at 0,0 > bottom left. > I'll probably write my own converter, as OBJ is kind of an important file > type we need to support. > Thanks, > > > Brandon Biggs <https://www.ski.org/users/brandon-biggs> > Engineer > > Smith-Kettlewell Eye Research Institute > Office: 415-345-2130 > Cell: 650-833-9394 > > ------------------------------ > *From:* Paul Harwood <[email protected]> > *Sent:* Wednesday, December 2, 2020 2:31 AM > *To:* Andrew C Aitchison <[email protected]> > *Cc:* Brandon Biggs <[email protected]>; [email protected] < > [email protected]> > *Subject:* Re: [gdal-dev] Converting OBJ to Geojson files with ogr2ogr > > .OBJ is a simple object mesh (or to put it in more traditional terms: > TIN) - it has shape but no data values and is not geolocated. > > I don't think there is any driver for OGR that will read .OBJ. > > You are going to problems with geolocation if you write your own. Geojson > requires that the geometries are geolocated - and in the current version > that they are in epsg:4326. That is not totally impossible - people have > been using .dxf files for gis data for decades and that format is also not > in theory geolocated. It is not a trivial problem though. > > I guess I would ask the usual question .. why? > > - what are you actually trying to achieve and why a GIS format like > GeoJSON? > > - If you have to use GeoJSON - I am guessing you are transferring some > data to something that reads GeoJSON only? In that case - can your source > produce .dxf? OGR can read .dxf. > > - If you only have the source in .OBJ - what other formats can the > destination read? Although, if you only have the source in .obj, I very > much doubt any of the GIS tools like GDAL are going to be able to help you. > It just is not a format used in GIS. > > It is a problem we solved in the ViRGiS projec <http://www.virgis.org>t - > since .obj is used a lot in VR. There we used an existing library to read > the .obj files - but that is in C# and I doubt that would help you. > > On Tue, 1 Dec 2020 at 20:15, Andrew C Aitchison <[email protected]> > wrote: > > On Tue, 1 Dec 2020, Brandon Biggs wrote: > > > Hello, > > I am wondering how to convert an obj file to a geojson file? I am using > ogr2ogr with the command: > > Ogr2ogr -f geojson output.geojson input.obj > > But get the error that ogr2ogr does not have an OBJ driver. I looked on: > > the vector drivers page<https://gdal.org/drivers/vector/index.html> > > but am unable to find a simple obj converter. I am wondering if there is > such a thing? I am probably going to write my own that does what I want, > because OBJ is so simple, I was just wondering if GDAL could already do it. > > I've never heard of OBJ, but that doesn't mean much. > > If you only want a read-only ogr driver you might want to look at > https://gdal.org/tutorials/vector_python_driver.html > if you would find a quick-n-dirty python quicker to write than C++. > > -- > Andrew C. Aitchison Kendal, UK > [email protected] > _______________________________________________ > gdal-dev mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/gdal-dev > >
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