developers,<div><br></div><div>I'm having a weird problem with las2txt and i think las2las as well. I am trying to subset this file (<a href="http://169.229.13.22/pub/LiDAR/ucd_04.las">http://169.229.13.22/pub/LiDAR/ucd_04.las</a>) using the commands:</div>
<div><br></div><div>las2txt --delimiter " " --parse xyzRGBc -i ucd_04.las -o ~/Desktop/04_0.txt -v -e "412725.875 4532149.5 412860.34375 4532359.5" --first-return-only --keep-classes 1</div><div><br></div>
<div>which returns</div><div><br></div><div><div>Opening ucd_04.las to fetch Header</div><div>Keeping classes with the values: 1 </div><div>---------------------------------------------------------</div><div> Clipping file to the extent</div>
<div>---------------------------------------------------------</div><div> minx: 412725.875000 miny: 4532149.500000 minz: 0.000000</div><div> maxx: 412860.343750 maxy: 4532359.500000 maxz: 0.000000</div><div>---------------------------------------------------------</div>
<div>Keeping first returns only.</div><div>Setting precisions from header to 2 2 2 8 </div><div>Using delimiter ' '</div><div>Writing points:</div><div> - : </div><div>0.error: detail::liblas::read_n<T> input stream is not readable</div>
</div><div><br></div><div>if i remove the '--first-return-only' argument the command succeeds</div><div><br></div><div>las2las using the same coordinates succeeds with both arguments however when using the 'first-returns-only' argument the resulting .las file has no points. </div>
<div><br></div><div>las2las just clipping the file to the coordinates shows that there are first returns within that region:</div><div><br></div><div><div>las2las -i ucd_04.las -o ~/Desktop/04_0.las -v -e "412725.875 4532149.5 412860.34375 4532359.5" </div>
<div>Opening ucd_04.las to fetch Header</div><div>---------------------------------------------------------</div><div> Clipping file to the extent</div><div>---------------------------------------------------------</div><div>
minx: 412725.875000 miny: 4532149.500000 minz: 0.000000</div><div> maxx: 412860.343750 maxy: 4532359.500000 maxz: 0.000000</div><div>---------------------------------------------------------</div><div>Writing output:</div>
<div> - : /home/peter/Desktop/04_0.las</div><div>0...</div></div><div><br></div><div>and </div><div><br></div><div>$ lasinfo ~/Desktop/04_0.las</div><div><br></div><div><br></div><div>lasinfo ~/Desktop/04_0.las ---------------------------------------------------------</div>
<div> Header Summary</div><div>---------------------------------------------------------</div><div><br></div><div> Version: 1.0</div><div> Source ID: 0</div><div> Reserved: 0</div>
<div> Project ID/GUID: '00000000-0000-0000-0000-000000000000'</div><div> System ID: ''</div><div> Generating Software: 'TerraScan'</div><div> File Creation Day/Year: 0/0</div>
<div> Header Byte Size 227</div><div> Data Offset: 229</div><div> Number Var. Length Records: None</div><div> Point Data Format: 1</div><div> Number of Point Records: 144379</div>
<div> Compressed: False</div><div> Number of Points by Return: 89804 42205 11178 1192 0 </div><div> Scale Factor X Y Z: 0.01 0.01 0.01</div><div> Offset X Y Z: -0.00 -0.00 -0.00</div>
<div> Min X Y Z: 412726.37 4532149.73 23.14</div><div> Max X Y Z: 412860.33 4532359.50 76.27</div><div> Spatial Reference: None</div><div><br></div><div>---------------------------------------------------------</div>
<div> Schema Summary</div><div>---------------------------------------------------------</div><div> Point Format ID: 1</div><div> Number of dimensions: 13</div><div> Custom schema?: false</div>
<div> Size in bytes: 28</div><div><br></div><div> Dimensions</div><div>---------------------------------------------------------</div><div> 'X' -- size: 32 offset: 0</div>
<div> 'Y' -- size: 32 offset: 4</div><div> 'Z' -- size: 32 offset: 8</div><div> 'Intensity' -- size: 16 offset: 12</div>
<div> 'Return Number' -- size: 3 offset: 14</div><div> 'Number of Returns' -- size: 3 offset: 14</div><div> 'Scan Direction' -- size: 1 offset: 14</div>
<div> 'Flightline Edge' -- size: 1 offset: 14</div><div> 'Classification' -- size: 8 offset: 15</div><div> 'Scan Angle Rank' -- size: 8 offset: 16</div>
<div> 'User Data' -- size: 8 offset: 17</div><div> 'Point Source ID' -- size: 16 offset: 18</div><div> 'Time' -- size: 64 offset: 20</div>
<div> </div><div>---------------------------------------------------------</div><div> Point Inspection Summary</div><div>---------------------------------------------------------</div><div> Header Point Count: 144379</div>
<div> Actual Point Count: 144379</div><div><br></div><div> Minimum and Maximum Attributes (min,max)</div><div>---------------------------------------------------------</div><div> Min X, Y, Z: <span class="Apple-tab-span" style="white-space:pre"> </span>412726.37, 4532149.73, 23.14</div>
<div> Max X, Y, Z: <span class="Apple-tab-span" style="white-space:pre"> </span>412860.33, 4532359.50, 76.27</div><div> Bounding Box:<span class="Apple-tab-span" style="white-space:pre"> </span>412726.37, 4532149.73, 412860.33, 4532359.50</div>
<div> Time:<span class="Apple-tab-span" style="white-space:pre"> </span>589039.231020, 589422.198199</div><div> Return Number:<span class="Apple-tab-span" style="white-space:pre"> </span>1, 4</div><div> Return Count:<span class="Apple-tab-span" style="white-space:pre"> </span>1, 4</div>
<div> Flightline Edge:<span class="Apple-tab-span" style="white-space:pre"> </span>0, 0</div><div> Intensity:<span class="Apple-tab-span" style="white-space:pre"> </span>1, 860</div><div> Scan Direction Flag:<span class="Apple-tab-span" style="white-space:pre"> </span>0, 1</div>
<div> Scan Angle Rank:<span class="Apple-tab-span" style="white-space:pre"> </span>-12, 13</div><div> Classification:<span class="Apple-tab-span" style="white-space:pre"> </span>1, 2</div><div> Point Source Id:<span class="Apple-tab-span" style="white-space:pre"> </span>16017, 16019</div>
<div> User Data:<span class="Apple-tab-span" style="white-space:pre"> </span>32, 32</div><div> Minimum Color (RGB):<span class="Apple-tab-span" style="white-space:pre"> </span>0 0 0 </div><div> Maximum Color (RGB):<span class="Apple-tab-span" style="white-space:pre"> </span>0 0 0 </div>
<div><br></div><div> Number of Points by Return</div><div>---------------------------------------------------------</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>(1) 89804<span class="Apple-tab-span" style="white-space:pre"> </span>(2) 42205<span class="Apple-tab-span" style="white-space:pre"> </span>(3) 11178<span class="Apple-tab-span" style="white-space:pre"> </span>(4) 1192</div>
<div><br></div><div> Number of Returns by Pulse</div><div>---------------------------------------------------------</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>(1) 47367<span class="Apple-tab-span" style="white-space:pre"> </span>(2) 62012<span class="Apple-tab-span" style="white-space:pre"> </span>(3) 30178<span class="Apple-tab-span" style="white-space:pre"> </span>(4) 4822</div>
<div><br></div><div> Point Classifications</div><div>---------------------------------------------------------</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>130234 Unclassified (1) </div><div><span class="Apple-tab-span" style="white-space:pre"> </span>14145 Ground (2) </div>
<div> -------------------------------------------------------</div><div> <span class="Apple-tab-span" style="white-space:pre"> </span>0 withheld</div><div> <span class="Apple-tab-span" style="white-space:pre"> </span>0 keypoint</div>
<div> <span class="Apple-tab-span" style="white-space:pre"> </span>0 synthetic</div><div> </div><div>Thanks very much for any guidance you can provide.</div><div><br></div><div>best,</div><div><br></div><div>Peter Tittmann</div>
<div>UC Davis Geography Graduate Group</div><div><br></div>