Questions tagged [point-cloud]

Point cloud is a set of data points in space. It is generated by 3D scanners. Used in construction of virtual scenes of real world spaces.

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pointcloud2_to_xyz_array not giving good visualization for ROS1 but working for ROS2

I have 2 setups: Setup #1: Ubuntu 20.04 focal Virtual cloud machine with arm64 architecture with ROS1 noetic, classic gazebo (which runs husky simulation from clearpath robotics) Setup #2: Ubuntu 22....
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How to deal with inexact pointcloud matching?

When running ICP(for example with SLAM) it's possible your next position does not have a point cloud which matches up with the prior point cloud due to resolution limits. How is this dealt with it? ...
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PointCloud2 parse to xyz array in ROS2

I'm trying to find a solution of converting PointCloud2 message data into xyz array for further analysis. Though, in my case I'm interested only in 2d application. The information is either scarce or ...
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Loop closure in 3d lidar slam

I am currently working on 3d LIDAR SLAM and trying to apply LOAM, LIO-SAM etc. I have already read some of these papers to get a better idea of the way they work. However, i did not find anything ...
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A short-range alternative to LiDAR

LiDAR is a very popular choice for long distance applications such as autonomous vehicles. I'm looking for a device that can give me a 3-dimensional representation of a close proximity environment (e....
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Merging multiple LIDARs real time

Is there a standard practice for merging the pointclouds generated by several LIDARs when there is overlap? For example, if my vehicle has two LIDARS (front and back) I'd rather fuse and deal with a ...
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Want to check RANSAC for a noiseless set of points; Error: Not enough inliers

I was just checking the functioning of my code implementing RANSAC sac_model: perpendicular by checking for a noiseless pointcloud. I have a few questions in the steps: I did the following: To ...
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Unintentional point cloud duplication during depth image conversion

I have a quite challenging question. I use ROS Melodic on Ubuntu18.04. My goal is to transform a ROS depth image to pointcloud2 format and show it in rviz. The theory seems ok, but I do not now where ...
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Reflective surface

Have you encountered the problem of reflective surfaces for realsense camera (d435 or t265) and lidar (A1 or A2). I would like to know what are the ways to solve problems with reflective surfaces for ...
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Trouble aligning/calibrating camera with laser scanner

I have a robot which has 2 multi-spectral cameras and 1 laser scanner attached. In the end I would like to have the images from the cameras aligned with the scanner so that I can have spectral ...
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Self localization inside machine of interest

I have a type of flight sensor interfaced with Arduino Uno via I2C. The sensor is VL53L0X i am getting the 1D measurement value of distance in mm which i can monitor using serial monitor in Arduino ...
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2D point cloud registration success probability

I am trying to implement localisation by storing images from a camera and their accompanying point clouds from a 2D lidar during mapping. During localisation I then use image matching to suggest the ...
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What is the concepts of submaps in LIDAR based graph slam algorithms?

I have been reading some slam papers recently and many of the papers mention building and performing scan matching on submaps instead of individual poses. Does it mean that a submap is just a single ...
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Applying initial guessing to LiDAR point cloud for ICP processing in Graph SLAM

I am currently in the process of implementing Graph SLAM using ICP and g2o in python 2.7 The data I have are pose data (4 x 4 transformation matrix) and lidar data ( in the format of [x y z 1] with ...
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What is the definition of the contents of PointCloud2?

What does the contents of PointCloud2 means in ROS? fields.offset? fields.datatype? ...
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How to convert PointCloud2 message to a grid?

I'm using a Velodyne sensor which publishes on /velodyne_points topic, and its class type is PointCloud2. Now I want to convert ...
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Calculating the distance of a point from point cloud data

I'm getting the x,y,z values for three points as follows: x : -0.357200 y: -0.205010 z: 0.940000 ...
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LiDAR Point cloud data reliability/quality

I'm trying to develop a quality measurement (kind of a metric) for the reliability/quality of given point cloud data (coming ...
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how to find space in point cloud larger than given l*b

Is their any method by using which I can find a space or gap in given point cloud which has size greater than given rectangle of size $l*b$ or a circle of radius $r$? This way my robot can make a path ...
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Relation between GraphSLAM and Iterative closest Point algorithm

I have lots of doubts about GraphSLAM, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. When I practically implement it I get matrix singularity error. I taken ...
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3D mapping using only a 2D Lidar

How can I map a 3D environment using only a 2D lidar? The lidar would be hand held and it would have 6 DoF. So if I move it in arbitrary motion in all 6DoF, I expect my algorithm to generate a 3D map ...
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ROS PCL: Help with Moving Least Squares filter

I'm trying to implement a simple ROS node to perform Moving Least Squares filtering on a sensor_msgs/PointCloud2 topic. I'm following this PCL tutorial, which uses ...
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Methods for odometry/IMU/Gyro free lidar pointcloud registration for pose estimation

I am currently trying to register a pointcloud in time to find my change in position and heading at each timestep (High speed application). So this is essentially an implementation of SLAM. I am ...
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Iterative Closest Point for 2-D LIDAR Data

I have two 2-D point clouds obtained from LIDAR (Light Detection And Ranging) scans at two different poses (positions and orientations) inside a circular structure, where a small object (vertical ...
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Forward monocular stereo vision (Structure from Motion)

I am looking for a library (or algorithm) that computes 3D scene (point cloud) from 2 consecutive images of a monocular sequence. I mean something like OpenSfM but only for 2 consecutive frames and ...
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Calibrating a laser scanner to a line camera

We have a high-resolution Riegl laser scanner and mounted atop it a Resonon Pika L, which is a hyperspectral camera which records one spatial column at a time, using the second dimension of the sensor ...
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Transforming Point Cloud to get Top Down Image [closed]

My task: I have a task where I am asked to track parcels(carton boxes) of different dimensions moving on a conveyor. I am using Asus Xtion pro camera mounted on top of a conveyor in any inclined ...
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