LidarData

Store sequence of lidar data

Since R2024b

Description

The LidarData object stores a sequence of lidar point cloud data.

Creation

Syntax

lidarData = scenariobuilder.LidarData

lidarData = scenariobuilder.LidarData(timestamps,pointClouds)

lidarData = scenariobuilder.LidarData(timestamps,pointClouds,Name=Value)

Description

lidarData = scenariobuilder.LidarData creates an empty LidarData object, lidarData.

lidarData = scenariobuilder.LidarData(timestamps,pointClouds) creates a LidarData object, lidarData, with the Timestamps and PointClouds properties set by the timestamps and pointClouds arguments, respectively. Additionally, this syntax sets the SampleRate, SampleTime, TimeDuration, and NumSamples properties.

lidarData = scenariobuilder.LidarData(timestamps,pointClouds,Name=Value) sets writable properties using one or more name-value arguments. For example, Name="lidar1" specifies the name of the lidar sensor as "lidar1".

Note

This object requires the Scenario Builder for Automated Driving Toolbox™ support package. You can install the Scenario Builder for Automated Driving Toolbox support package from the Add-On Explorer. For more information about installing add-ons, see Get and Manage Add-Ons.

Input Arguments

timestamps — Timestamps of lidar data

N-element numeric column vector | N-element datetime array | N-element duration array

Timestamps of the lidar data, specified as an N-element numeric column vector, an N-element datetime array, or an N-element duration array. N is the number of timestamps. Each element in the timestamps argument specifies the time at which the corresponding lidar data was collected. If you specify an N-element numeric column vector, units must be in seconds.

This argument sets the Timestamps property.

pointClouds — Lidar point cloud data

N-by-1 array of pointCloud objects | N-by-1 string array | N-by-1 cell array of character vectors | string scalar

Lidar point cloud data, specified as an N-by-1 array of pointCloud objects, N-by-1 string array, N-by-1 cell array of character vectors, or a string scalar. N is the number of timestamps.

If you specify an N-by-1 string array or an N-by-1 cell array of character vectors, each element in the array represents a point cloud filename, an absolute or relative path of a point cloud file. The point cloud file must be of PLY or PCD format.

If you specify a string scalar, the string must specify an absolute or relative path to a folder containing point cloud files.

This argument sets the PointClouds property.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: scenariobuilder.LidarData(Name="lidar1") specifies the name of the lidar sensor as "lidar1".

Name — Name of lidar sensor

'' (default) | string scalar | character vector

Name of the lidar sensor, specified as a string scalar or character vector.

This argument sets the Name property.

Data Types: char | string

SensorParameters — Optional lidar sensor parameters

[] (default) | lidar parameters

Optional lidar sensor parameters, specified as lidar parameters specifying sensor characteristics, mounting information, or transformations, such as a rigidtform3d object.

This argument sets the SensorParameters property.

Attributes — Optional lidar attributes

[] (default) | N-by-1 cell array

Optional lidar attributes, specified as an N-by-1 cell array. N is the number of timestamps. Each cell contains the additional lidar attributes, such as classification labels, detected at the corresponding timestamp.

This argument sets the Attributes property.

Data Types: cell

Properties

Name — Name of lidar sensor

'' (default) | string scalar | character vector

Name of the lidar sensor, specified as a string scalar or character vector.

Data Types: char | string

NumSamples — Number of point cloud samples

0 (default) | nonnegative integer

This property is read-only.

Number of point cloud samples, represented as a nonnegative integer.

Data Types: uint8 | uint16 | uint32 | uint64

Duration — Time duration

0 (default) | nonnegative scalar

This property is read-only.

Time duration for which the lidar data was acquired, represented as a nonnegative scalar. Units are in seconds.

Data Types: double

SampleRate — Mean sample rate of lidar data

0 (default) | nonnegative scalar

This property is read-only.

Mean sample rate of the lidar data, represented as a nonnegative scalar. This value defines the number of point cloud frames per second. Units are in hertz.

Data Types: double

SampleTime — Mean sample time of lidar data

0 (default) | nonnegative scalar

This property is read-only.

Mean sample time of the lidar data, represented as a nonnegative scalar. This value defines the mean time interval between two consecutive point cloud frames. Units are in seconds.

Data Types: double

Timestamps — Timestamps of lidar data

[] (default) | N-element numeric column vector | N-element datetime array | N-element duration array

This property is read-only after object creation. To set this property, use the timestamps argument when calling the scenarioBuilder.LidarData function.

Timestamps of the lidar data, represented as an N-element numeric column vector, an N-element datetime array, or an N-element duration array. N is the number of timestamps. Each element in the Timestamps property specifies the time at which the corresponding lidar data was collected. If you specify an N-element numeric column vector, units must be in seconds.

When you initialize the object with timestamps and pointClouds, the object arranges the data by the input timestamps in increasing order.

PointClouds — Lidar point cloud data

[] (default) | N-by-1 string array

This property is read-only after object creation. To set this property, use the pointClouds argument when calling the scenarioBuilder.LidarData function.

Lidar point cloud data, represented as an N-by-1 string array. N is the number of timestamps. Each element in the array represents a point cloud filename, an absolute or a relative path of a point cloud file.

SensorParameters — Optional lidar sensor parameters

[] (default) | lidar parameters

Optional lidar sensor parameters, specified as lidar parameters specifying sensor characteristics, mounting information, or transformations, such as a rigidtform3d object.

Attributes — Optional lidar attributes

[] (default) | N-by-1 cell array

Optional lidar attributes, specified as an N-by-1 cell array. N is the number of timestamps. Each cell contains the additional lidar attributes, such as classification labels, detected at the corresponding timestamp.

Data Types: cell

Object Functions

add	Add data to lidar data object
remove	Remove data from sensor data object
read	Read data from sensor data object
copy	Create copy of sensor data object
crop	Crop data from sensor data object
synchronize	Synchronize sensor data with reference sensor information
play	Play point clouds from lidar data object
datastore	Create datastore from sensor data object
normalizeTimestamps	Normalize timestamps of sensor data object

Examples

Create Lidar Data Object and Add Data Samples

Specify a path containing a sequence of point cloud files.

files = dir(fullfile(toolboxdir("vision"),"visiondata","pcdmapseq","*.pcd"));
pcds = strcat({files.folder},filesep,{files.name})';

Specify timestamps for each point cloud in the point cloud data.

timestamps = (1:4)';

Create an empty lidar data object.

lidarData = scenariobuilder.LidarData(Name="LidarSensor")

lidarData = 
  LidarData with properties:

                Name: "LidarSensor"

          NumSamples: 0
            Duration: 0
          SampleRate: 0
          SampleTime: 0
          Timestamps: []

         PointClouds: []
    SensorParameters: []

          Attributes: []

Add your data samples to the lidar data object.

add(lidarData,timestamps,pcds)

Visualize the lidar data object.

play(lidarData)

Version History

Introduced in R2024b