Questions tagged [point-cloud]

A point cloud is an unstructured set of points, each defined by x,y,z co-ordinates.

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1answer
39 views

Determining pixel size based on LiDAR point cloud density

I have a point cloud with a density of 8 points/m². I would like to generate a digital elevation model (DEM) from it, but I don't know what resolution to set as the raster pixel. So I would like to ...
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1answer
42 views

Ideal procedure to deal with faulty data for generation of LiDAR trajectory

The reason for this post is to understand possible remedial measures when one is dealing with a lidar dataset that is faulty (incorrectly populated, missing trajectory information etc.). Obviously, re-...
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0answers
21 views

Reclassify points within a bounding box with PDAL

I have a list of 3D bounding boxes manually drawn around noise points and I want to reclassify them as noise. One option would be to simply drop them but, in this particular case, I would want to have ...
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0answers
12 views

Attribute/dimension adding to the lasfile

.LAS files have different dimensions as x, y, z, etc. Suppose, I want to add another dimension with the name "n". How to do it correctly? I attempted to use the following pdal pipeline: ...
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2answers
31 views

Highest LiDAR point return per sq m?

I currently have at my disposal QGIS and Trimble Business Center. I am looking for semi-automated solution for extracting the single highest lidar point return per square meter. My area of interest is ...
3
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1answer
52 views

QGIS point cluster correlation

Is there a way to (preferably in QGIS that I actually can use) analyze two sets of point layers and describe the correlation in the espective cummulations? For instance, I have points that experts ...
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0answers
21 views

TPI calculation by PDAL [closed]

Is there a convenient way to calculate the topographic position index by PDAL? I have LAS file and what I do is iteratively for every point calculate the TPI. The coordinate information I take from ...
2
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0answers
30 views

Big .las to raster converting by writers.gdal

I have a script: pipeline = [ path, { "filename": out_path, "gdaldriver": "GTiff", "resolution": 1, "output_type": "max", ...
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0answers
44 views

Assigning a CRS to a LAS

Is there a way to assign CRS to the LAS file through Python if the name of CRS is corrupted and looks like following?
2
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1answer
43 views

Incorrect CRS affects on writers.gdal result

I have a .las file with CRS that is not decoded correctly and looks like following: At the same time the part of metadata which (as I understand) stands for CRS looks like this: "...
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0answers
30 views

How to invert LAS files

I have a bunch of LAS files which are supposed to show data underwater but the depth (z) is poisitive rather than negative so they are inverted. I'm looking for the fastest way to invert/flip them on ...
0
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1answer
29 views

Which options should I use when creating textures for better buildings quality Agisoft?

I am new to Agisoft and I created a 3D module. The textures of the buildings don't look that good. I would like to know which options should I use in the Build Texture tab to make it better. Or maybe ...
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0answers
22 views

writers.gdal wrong pixel size

I want to convert the .las file into .tif by the following pipeline: pipeline = [ input_path, { "type": "writers.gdal", "...
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0answers
24 views

filters.delaunay doesn't work

I have pdal 2.2.0 My pipeline is the following: pipeline = [ input_path, { "type": "filters.elm" }, { "type": &...
2
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1answer
22 views

Viewing LiDAR datasets at lower zoom levels in ArcGIS Pro

Is there a way to display LiDAR datasets at lower zoom levels in ArcGIS Pro? Currently, I can only see the point cloud at a zoom of around 1:800. What I would like: view the point cloud/LiDAR dataset ...
1
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2answers
70 views

Add voxel attributes to LAS point cloud

I would like to add data from voxels to a point cloud. Imagine I calculated some voxel statistics with voxel_metrics(), for example: voxels <- voxel_metrics(las, length(X), res=0.1, all_voxels=TRUE)...
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0answers
26 views

Point cloud data on a grid

I have a point database marking different locations (presence of an animal) on a grid of 250 m x 250 m over a certain period of time. Each one of these points have a date. By intersecting the grid ...
6
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1answer
112 views

Calculating grid_metrics() in a loop, using column name within variable

I want to calculate grid_metrics() for several fields of my point cloud, using several functions. I want to perform this in loops to make my code look cleaner. Basically I want this: # loop through ...
4
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1answer
102 views

Get eigenvalues of large point cloud using lidR

I have some very big TLS point clouds (up to 400 million points) and want to assign the eigenvalues to each point in order to later calculate geometric features like planarity or sphericity. I use R ...
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0answers
19 views

Tool to colorize Pointcloud from 360° Laserscann

I have a Pointcloud with panoramic images that I want to colorize. What tools could I use for this. I looked into PDAL but from what I read, PDAL needs orthographic pictures. Is there another tool ...
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0answers
50 views

GDAL: GeoTIFF bands that represents surface classification into point cloud

I have a file originally in ECW format, after being able to convert it into GeoTIFF since then I can open it in QGIS, I can see the result as: red band: buildings. green band: vegetation. blue band: ...
2
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1answer
26 views

pdal truncating values when writing ply

When using pdal to either translate to ply file or split a ply file in smaller chunks, it appears to be truncating values so I end up with point clouds with stripping. This does not occur with other ...
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1answer
139 views

Extracting trees/vegetation as separate point cloud using ArcGIS Pro

I have ArcGIS Pro 2.4 with 3D Analyst and Spatial Analyst Extensions. I would like to extract all points from a point cloud (.las) file that match a certain classification to a new, separate point ...
0
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1answer
56 views

QGIS point clouds: hide flat pane in 3D view

After successfully loading .laz point cloud data to QGIS 3.18 on Win 10, I am able to show the data in 3D view. However, the data is visualized twice: once as a flat pane with the same symbolization ...
3
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1answer
2k views

Open .laz point clouds not available in QGIS 3.18

The recent release of QGIS 3.18 supports point cloud data. As can be seen on the screenshot in the linked Visual Changelog (above), .laz files should be supported. However, in my installation on ...
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0answers
33 views

Obtaining city model for modification in CityEngine from LiDAR point cloud

In ArcMap I transformed the point cloud into Multipoints and then into Singlepoints and I obtained this model in ArcScene. Is it possible to transform these points into 3D objects? Finally, I would ...
3
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1answer
341 views

How to get VLRs from a .las file with laspy

I have a .las point cloud data file that I am trying to get the vlr data from. I have found this link - Update EVLR header info for .LAS file using laspy and have read the docs on Laspy - https://...
2
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1answer
78 views

FME SherbandGeneralizer - estimate time for "Optimizing Memory usage"

I have a workspace with a pointcloud of 240.000.000 points as input, goal is generalized countour lines, that do not intersect each other. The workspace mainly consists of (cp. screenshot) ...
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0answers
219 views

Combine LiDAR data with OpenStreetMap

I have already built Ubuntu for OpenStreetMap and I have some LiDAR data file in LAS/LAZ format. Is it possible to make LiDAR data appear in 2D and be a part of OpenStreetMap? If it is, how? I have ...
2
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1answer
229 views

Getting LiDAR point cloud point spacing using PDAL

I am trying to use PDAL (in Python) to extract metadata from a LiDAR point cloud (.las). I am using the "pdal info" command and applying different flags (e.g. -metadata, -stats) to get ...
5
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1answer
310 views

Finding the minimum spanning tree (MST)

I have a set of points at which I want to find the minimum spanning tree with PostGIS. I have no lines between them, I only have the starting point from which to start building the tree (the ...
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0answers
53 views

Extract vertical planes from Point cloud

I am looking for a tool/method for extraction of vertical planes (building facades, fences, ...) from mobile mapping point clouds. There is software (Cloud compare e.g.) that offers RANSAC plane ...
2
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1answer
84 views

Creating buffer around points belonging to object using lidR

I would like to create a 3D buffer around powerlines inside a LAS file that contains forest and power lines in lidR (R package). If I would manually delineate the line features and export to an ...
4
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1answer
333 views

lidR: Save LAS files from a clip_roi list

I have clipped a point cloud with a shapefile containing multiple polygons, using clip_roi() function. The result is a list of LAS files. However, when I try to loop through the list and save each ...
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0answers
145 views

Comparing two point clouds, one in WGS84 and the other in ECEF

I'm really a newbie and this task seems over my head. Suppose you have one cloud from LiDAR (a LAS file) with coordinates in WGS84 and another cloud, obtained from structure-from-motion, in ECEF. They ...
1
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1answer
143 views

arcgis.learn show_batch() index error and lr_find() runtime error while using pointcnn for LiDAR segmentation

I am trying to segment vegetation from LiDAR point cloud using PointCNN on Jupyter notebook. But I am getting Index Error on running show_batch() and runtime error on running lr_find() while using ...
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0answers
98 views

How to improve LiDAR classification in GlobalMapper

I have a LiDAR point cloud that has a density of 16.4 points per m^2 and spacing of 0.2469m, and am trying to extract trees from it but the classification came with a lot of messy points in classes ...
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0answers
71 views

Cesium | Any Alternatives to 3dtilesets to visualize point cloud data?

I'm in the early stages of developing a web-based visualization for multiple GIS data sources (imagery, vector data sets, terrain, point cloud...etc). I am using the Cesium javascript library for ...
1
vote
1answer
137 views

Subset a lascatalog point cloud within a function while calculating grid_metrics

I am trying to create subsets of a point cloud based on the ScanAngleRank and compute some metrics for each subset. Then return a stack of values(rasters) for the metric. I modified the rumple index ...
2
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0answers
51 views

Separating ("high enough") trees from "lower height" vegetation? In abstract (non-RGB) .xyz point cloud

Suppose I want to select trees that are "high enough", but the data contains other vegetation, like bushes and smaller trees. My data is abstract (non-RGB) .xyz point cloud. I.e. there's only ...
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0answers
83 views

pdal: why does filters.hag and filters.ferry with HeightAboveGround=Z reset original points to Z=0?

pdal: why does filters.hag and filters.ferry with HeightAboveGround=Z reset original points to Z=0? I'm essentially trying out the example-3, given here: https://pdal.io/stages/filters.hag.html#...
2
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1answer
100 views

Applying machine learning methods in orfeo toolbox into DEM raster

I would like to apply machine learning methods in orfeo toolbox to classify some landscape features such as shrub and coarse woody debris in woodland. I created DEM raster image from very dense ground ...
1
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1answer
134 views

Using function lasdetectshape of lidR

I would like to try "lasdetectshape" in lidR package to detect line pattern objects in my point cloud. library(lidR) las <- readLAS("9a-1.las", select = 'xyzicnrRGB') las <- lasdetectshape(las,...
0
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1answer
135 views

Point cloud - Why don't all the points show up in AGOL or ArcGIS Pro?

Whenever I upload a LAS file in ArcGIS Pro, not all the points are shown. And there are even less points when I upload it to AGOL. Is there a maximum of points ArcGIS Pro and AGOL can show ? If yes,...
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0answers
52 views

Showing all points of point cloud layer using ArcGIS Pro

I have a point cloud file of some trees. I first convert this to a LAS using some converter tool. I then open this LAS file in ArcGIS Pro and somehow it doesn't show all points there is. Even if I set ...
0
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1answer
235 views

Treetop location in 3D: How can I find the coordinates (x,y,z) of point cloud's local maxima within polygon vectors?

I'm doing forestry analysis of some point cloud data and I have used segmentation procedures (i.e. watershed algorithm, etc..) to delineate the crown boundaries of individual trees in 2D. The vector ...
2
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0answers
1k views

Converting from .las to .ply and vice versa in Python? [closed]

I am trying to convert a .las/.laz file into .ply file, read the .ply file, do some processing on it and then convert it back to .las/.laz file. Is there any Python implementation for this? For ...
1
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1answer
217 views

Retrieve the elevation from a point cloud with lastools?

I have a general question about how can I get the elevation (z) data from a pointcloud (las) along a trajectory. I have a shape file with x, y coordinates and I have the related .las files. And I am ...
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0answers
346 views

How to georeference point cloud data that was no spatial information?

I'm working on a project right now that the final goal is to compare two DTMs of a glacier surface from different years to visualize the change over time of the glacial surface. The first DTM was ...
5
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3answers
623 views

Removing noise from point cloud with lidR package

I have unclassified Terrestrial Laser Scanning (TLS) point cloud data which has some noise. Is there a function in the lidR package which can be used to remove noise?