LOAMPoints

Object for storing LOAM feature points

Since R2022a

Description

The LOAMPoints object enables you to store lidar odometry and mapping (LOAM) feature points for registration. Use the detectLOAMFeatures function to detect feature points and store them in a LOAMPoints object. Use the pcregisterloam function to find the transformation between two LOAMPoints objects.

Creation

Syntax

points = LOAMPoints(location,label,laserID)

Description

points = LOAMPoints(location,label,laserID) constructs a LOAMPoints object from the specified 3-D point coordinates location. Specify the categorical label label for each point, and an identifier laserID for each point that relates to the laser that detected the point.

Input Arguments

location — Point locations

M-by-3 matrix of [x y z] coordinates

Point locations, specified by an M-by-3 matrix of [x y z] coordinates, where M is the number of points.

label — Categorical label of each point

M-element categorical array

Categorical label of each point, specified as an M-element categorical array, where M is the number of points. Each point can be of category 'sharp-edge', 'less-sharp-edge', 'planar-surface', or 'less-planar-surface'.

laserID — Laser identifier

M-element vector of positive integers

Laser identifier, specified as an M-element vector of positive integers, where M is the number of points. Each element is the ID of the laser that detected the corresponding point.

Properties

Location — LOAM point locations

M-by-3 matrix of [x y z] coordinates

This property is read-only.

Point locations, specified by an M-by-3 matrix of [x y z] coordinates, where M is the number of points.

Label — Categorical label of each point

M-element categorical array

This property is read-only.

Categorical label of each point, specified as an M-element categorical array, where M is the number of points. Each point can be of category 'sharp-edge', 'less-sharp-edge', 'planar-surface', or 'less-planar-surface'.

Count — Number of points

positive integer

This property is read-only.

Number of points, specified as a positive integer.

Object Functions

downsampleLessPlanar	Downsample less planar surface points
transformPointsForward	Apply forward geometric transformation to points
show	Visualize LOAM feature points

Examples

Detect and Visualize LOAM Feature Points

Load an organized lidar point cloud from a MAT file into the workspace.

ld = load("drivingLidarPoints.mat");
ptCloudOrg = ld.ptCloud;

Detect lidar odometry and mapping (LOAM) feature points.

points = detectLOAMFeatures(ptCloudOrg);

Visualize the LOAM points.

figure
show(points)

References

[1] Zhang, Ji, and Sanjiv Singh. “LOAM: Lidar Odometry and Mapping in Real-Time.” In Robotics: Science and Systems X. Robotics: Science and Systems Foundation, 2014. https://doi.org/10.15607/RSS.2014.X.007.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Limitations:

The show function of this object does not support code generation.

GPU Code Generation

Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Limitations:

The order of points in the LOAMPoints object from code generation can be slightly different from that in usual MATLAB output. However, the corresponding mapping between the Location and Label properties remains the same.

Version History

Introduced in R2022a

R2023b: Support for GPU code generation

The LOAMPoints object supports GPU code generation using GPU Coder™.