[pdal] Troubleshooting GDAL writer and "Grid width out of range."

[Theo Hartsook]

Hi Howard,

Thank you for very fast reply. Unfortunately the --nostream option did not
help. I confirmed that my filters are returning points. As a workaround I
decided to generate a new copy of the point cloud each time and save it to
disc before creating the rasters. Thank you for sharing the
expressions filter, that will be a very useful tool!

Best,
Theo

On Fri, Jan 27, 2023 at 12:44 PM Howard Butler <howard at hobu.co> wrote:

> Try the --nostream option when running `pdal pipeline` and see if it will
> calculate grid extents for you. Additionally, make sure your limits aren't
> causing zero points to come through your filters.
>
> Finally, take a look at filters.expression instead of filters.range, which
> was just added for PDAL 2.5
> https://pdal.io/en/stable/stages/filters.expression.html The expression
> filter is more powerful than filters.range and probably easier to write.
>
> Hope this helps,
>
> Howard
>
> > On Jan 27, 2023, at 2:12 PM, Theo Hartsook <theo.hartsook at gmail.com>
> wrote:
> >
> > Hi everyone,
> >
> > I am having trouble figuring out where the problem is with a script I am
> working on.
> >
> > My goal is to rasterize a point cloud at different height ranges (i.e.
> 0-10m height above ground, 10.1-20m height above ground, etc.).
> >
> > The point cloud stored HeightAboveGround to an extra dimension and I
> confirmed that the values are correct by viewing in CloudCompare.
> >
> > The steps I use are the following:
> >
> > {'type':'readers.las', 'filename':input_las,
> 'extra_dims':'HeightAboveGround=float32'}
> > {'type':'filters.range', 'limits':'HeightAboveGround[0:10]'}
> >
> {'filename':band,'gdaldriver':'GTiff','output_type':'count','resolution':'1','type':'writers.gdal'}
> >
> > This leads to a strange part. Mostly these steps work and produce
> rasters that look how I expect at that height range. It has never failed on
> the lowest height range, say 0-10m. However, on following height ranges,
> say 10-20m, I receive the following error:
> > "RuntimeError: writers.gdal: Grid width out of range."
> > I am not sure where in my process is triggering this error, since it
> works on the prior height range. The range filter works at each height
> range, even when the GDAL step fails. I confirmed this by writing the
> filtered point clouds to disc instead of rasterizing them and viewing them
> in CloudCompare.
> >
> > I created another version of this same point cloud where the Z values
> were replaced with HeightAboveGround using the ferry filter and then saved
> to disc. When I change the range filter to select for Z instead of height
> above ground, the raster step doesn't throw an error at any height range
> and produces the results I expect. However, if I try to add these steps to
> the pipeline when reading the original point cloud (read point cloud with
> HeightAboveGround, ferry HeightAboveGround to Z, then range filter for Z
> values), I still get the Grid width out of range error on the second height
> range.
> >
> > I tested one last thing. I wondered if there was some error with how my
> script generated the height ranges. So I manually ran the filter at the
> next increment (10-20m) and unfortunately still got the same error. This
> scenario has me quite confused and I would appreciate any help and advice!
> My best guess from my tests is that the problem lies with the GDAL step,
> not prior.
> >
> > Best regards,
> > Theo Hartsook
> > _______________________________________________
> > pdal mailing list
> > pdal at lists.osgeo.org
> > https://lists.osgeo.org/mailman/listinfo/pdal
>
>
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