Lidar Class Reference

Class for Lidar control and data retrieval.
It provides methods to initialize the Lidar, retrieve data, and enable positional tracking.
Supports both live sensor input and OSF file playback. More...

Functions
	Lidar ()
	Lidar constructor. More...
	~Lidar ()
	Lidar destructor. More...
sl::ERROR_CODE	open (InitLidarParameters params)
	Opens the Lidar. More...
bool	isOpened () const
	Checks if the Lidar is opened. More...
InitLidarParameters	getInitParameters () const
	Returns the initialization parameters used to open the Lidar. More...
LidarInformation	getLidarInformation () const
	Returns the Lidar information. More...
CUcontext	getCUDAContext () const
	Returns the CUDA context used by the Lidar when GPU mode is enabled. More...
sl::ERROR_CODE	read ()
	Reads the next data chunk. More...
sl::ERROR_CODE	grab ()
	Grabs a new frame. More...
sl::ERROR_CODE	retrieveMeasure (sl::Mat &mat, sl::LIDAR_MEASURE measure, sl::Resolution res=sl::Resolution(0, 0), sl::MEM type=sl::MEM::CPU, sl::VIEW_COLOR_MAP color_map=sl::VIEW_COLOR_MAP::AUTO, cudaStream_t stream=0)
	Retrieves a measure texture (raw float data). More...
sl::ERROR_CODE	retrieveView (sl::Mat &mat, sl::LIDAR_VIEW view, sl::Resolution res=sl::Resolution(0, 0), sl::VIEW_COLOR_MAP color_map=sl::VIEW_COLOR_MAP::AUTO, cudaStream_t stream=0)
	Retrieves a view texture (visual data). More...
sl::Timestamp	getTimestamp (sl::TIME_REFERENCE reference_time) const
	Returns the timestamp of the frame or the current time. More...
float	getCurrentFPS () const
	Returns the current framerate at which the grab() method is successfully called. More...
sl::ERROR_CODE	getSensorsData (sl::SensorsData &data, sl::TIME_REFERENCE reference_time=sl::TIME_REFERENCE::CURRENT)
	Retrieves sensors data (IMU). More...
sl::ERROR_CODE	enablePositionalTracking (PositionalTrackingLidarParameters params=PositionalTrackingLidarParameters())
	Enables positional tracking. More...
void	disablePositionalTracking ()
	Disables positional tracking. More...
sl::POSITIONAL_TRACKING_STATE	getPosition (sl::Pose &pose, sl::REFERENCE_FRAME reference_frame=sl::REFERENCE_FRAME::WORLD)
	Retrieves the current position. More...
sl::ERROR_CODE	enableRecording (RecordingLidarParameters params)
	Enables recording. More...
void	disableRecording ()
	Disables recording. More...
int	getSVOPosition () const
	Gets the current SVO/OSF playback position (frame index). More...
sl::ERROR_CODE	setSVOPosition (int frame_number)
	Sets the SVO/OSF playback position (frame index). More...
int	getSVONumberOfFrames () const
	Gets the total number of frames in the SVO/OSF file. More...
int	getSVOPositionAtTimestamp (sl::Timestamp timestamp) const
	Retrieves the frame index within the SVO/OSF file corresponding to the provided timestamp. More...
void	setTimestampBaseOffset (int64_t offset)
	Sets the base timestamp offset for converting OSF sensor timestamps to Unix epoch. More...
int64_t	getTimestampBaseOffset () const
	Gets the base timestamp offset for OSF playback. More...
void	pauseSVOReading (bool status)
	Pauses or resumes SVO/OSF reading. More...
void	close ()
	Closes the Lidar. More...

Static Functions
static std::vector< LidarDeviceProperties >	getDeviceList ()
	Returns a list of available Lidar devices. More...
static std::vector< LidarDeviceProperties >	getStreamingDeviceList ()
	Returns a list of streaming Lidar devices. More...

Detailed Description

Class for Lidar control and data retrieval.
It provides methods to initialize the Lidar, retrieve data, and enable positional tracking.
Supports both live sensor input and OSF file playback.

Note

Beta: The Lidar class is currently in beta. Interfaces and behavior may change in future SDK releases.

// Example usage with live sensor
sl::Lidar lidar;
sl::InitLidarParameters init_params;
init_params.input.setFromStream("192.168.1.50");
lidar.open(init_params);
lidar.grab();
sl::Mat point_cloud;
lidar.retrieveMeasure(point_cloud, sl::LIDAR_MEASURE::XYZ);
lidar.close();

// Example usage with OSF file playback (similar to SVO for Camera)
sl::Lidar lidar;
sl::InitLidarParameters init_params;
init_params.input.setFromSVOFile("/path/to/recording.osf");
lidar.open(init_params);
while (lidar.grab() == sl::ERROR_CODE::SUCCESS) {
    sl::Mat point_cloud;
    lidar.retrieveMeasure(point_cloud, sl::LIDAR_MEASURE::XYZ);
    // Process point cloud...
}
lidar.close();

Constructor and Destructor

Lidar()

Lidar

(

)

Lidar constructor.

~Lidar()

~Lidar

(

)

Lidar destructor.

Functions

getDeviceList()

static std::vector<LidarDeviceProperties> getDeviceList ( )

static

Returns a list of available Lidar devices.

Returns

A vector of LidarDeviceProperties.

getStreamingDeviceList()

static std::vector<LidarDeviceProperties> getStreamingDeviceList ( )

static

Returns a list of streaming Lidar devices.

Returns

A vector of LidarDeviceProperties.

open()

sl::ERROR_CODE open

(

InitLidarParameters

params

)

Opens the Lidar.

Parameters

params

: The initialization parameters.

Returns

ERROR_CODE::SUCCESS if successful, otherwise an error code.

isOpened()

bool isOpened

(

)

const

Checks if the Lidar is opened.

Returns

True if opened, false otherwise.

getInitParameters()

InitLidarParameters getInitParameters

(

)

const

Returns the initialization parameters used to open the Lidar.

Returns

The InitLidarParameters.

getLidarInformation()

LidarInformation getLidarInformation

(

)

const

Returns the Lidar information.

Returns

The LidarInformation containing device info and sensor configuration.

getCUDAContext()

CUcontext getCUDAContext

(

)

const

Returns the CUDA context used by the Lidar when GPU mode is enabled.

This method allows you to retrieve the CUDA context created by or provided to the SDK, enabling shared GPU memory operations with other CUDA-enabled libraries.

Returns

The CUDA context, or nullptr if GPU mode is disabled or not initialized.

read()

sl::ERROR_CODE read

(

)

Reads the next data chunk.

Returns

ERROR_CODE::SUCCESS if successful.

grab()

sl::ERROR_CODE grab

(

)

Grabs a new frame.

Returns

ERROR_CODE::SUCCESS if successful.

retrieveMeasure()

sl::ERROR_CODE retrieveMeasure	(	sl::Mat &	mat,
		sl::LIDAR_MEASURE	measure,
		sl::Resolution	res = sl::Resolution(0, 0),
		sl::MEM	type = sl::MEM::CPU,
		sl::VIEW_COLOR_MAP	color_map = sl::VIEW_COLOR_MAP::AUTO,
		cudaStream_t	stream = 0
	)

Retrieves a measure texture (raw float data).

Parameters

mat	: The sl::Mat to store the measure.
measure	: The type of measure to retrieve.
res	: The resolution to resize the measure (optional).
type	: The memory type (CPU or GPU).
color_map	: The colormap if applicable.
stream	: The CUDA stream for asynchronous operations (optional, GPU mode only).

Returns

ERROR_CODE::SUCCESS if successful.

retrieveView()

sl::ERROR_CODE retrieveView	(	sl::Mat &	mat,
		sl::LIDAR_VIEW	view,
		sl::Resolution	res = sl::Resolution(0, 0),
		sl::VIEW_COLOR_MAP	color_map = sl::VIEW_COLOR_MAP::AUTO,
		cudaStream_t	stream = 0
	)

Retrieves a view texture (visual data).

Parameters

mat	: The sl::Mat to store the view.
view	: The type of view to retrieve.
res	: The resolution to resize the view (optional).
color_map	: The colormap to use.
stream	: The CUDA stream for asynchronous operations (optional, GPU mode only).

Returns

ERROR_CODE::SUCCESS if successful.

getTimestamp()

sl::Timestamp getTimestamp

(

sl::TIME_REFERENCE

reference_time

)

const

Returns the timestamp of the frame or the current time.

This function can also be used when playing back an OSF file.

Parameters

reference_time

: The selected TIME_REFERENCE. - TIME_REFERENCE::IMAGE : timestamp of the last grabbed frame. - TIME_REFERENCE::CURRENT : current system time.

Returns

The timestamp in nanoseconds. 0 if not available.

Note

As this function returns UNIX timestamps, the reference it uses is common across several Lidar instances.

sl::Timestamp last_frame_timestamp = lidar.getTimestamp(sl::TIME_REFERENCE::IMAGE);
sl::Timestamp current_timestamp = lidar.getTimestamp(sl::TIME_REFERENCE::CURRENT);
 
std::cout << "Latest frame timestamp: " << last_frame_timestamp << "ns from Epoch." << std::endl;
std::cout << "Current timestamp: " << current_timestamp << "ns from Epoch." << std::endl;

getCurrentFPS()

float getCurrentFPS

(

)

const

Returns the current framerate at which the grab() method is successfully called.

The returned value is based on the difference of timestamps between two successful grab() calls.

Returns

The current SDK framerate.

Warning

The returned framerate (number of frames grabbed per second) can be lower than the Lidar mode fps if the grab() function runs slower than the data stream or is called too often.

float current_fps = lidar.getCurrentFPS();
std::cout << "Current framerate: " << current_fps << std::endl;

getSensorsData()

sl::ERROR_CODE getSensorsData	(	sl::SensorsData &	data,
		sl::TIME_REFERENCE	reference_time = sl::TIME_REFERENCE::CURRENT
	)

Retrieves sensors data (IMU).

Parameters

data	: The SensorsData object to store the data.
reference_time	: The reference time for the data.

Returns

ERROR_CODE::SUCCESS if successful.

enablePositionalTracking()

sl::ERROR_CODE enablePositionalTracking

(

PositionalTrackingLidarParameters

params = PositionalTrackingLidarParameters()

)

Enables positional tracking.

Parameters

params

: The positional tracking parameters (optional).

Returns

ERROR_CODE::SUCCESS if successful.

disablePositionalTracking()

void disablePositionalTracking

(

)

Disables positional tracking.

getPosition()

sl::POSITIONAL_TRACKING_STATE getPosition	(	sl::Pose &	pose,
		sl::REFERENCE_FRAME	reference_frame = sl::REFERENCE_FRAME::WORLD
	)

Retrieves the current position.

Parameters

pose	: The Pose object to store the position.
reference_frame	: The reference frame for the position.

Returns

POSITIONAL_TRACKING_STATE.

enableRecording()

sl::ERROR_CODE enableRecording

(

RecordingLidarParameters

params

)

Enables recording.

Parameters

params

: The recording parameters.

Returns

ERROR_CODE::SUCCESS if successful.

disableRecording()

void disableRecording

(

)

Disables recording.

getSVOPosition()

int getSVOPosition

(

)

const

Gets the current SVO/OSF playback position (frame index).

Returns

The current frame index, or -1 if not in playback mode.

setSVOPosition()

sl::ERROR_CODE setSVOPosition

(

int

frame_number

)

Sets the SVO/OSF playback position (frame index).

Parameters

frame_number

: The frame index to seek to.

Returns

ERROR_CODE::SUCCESS if successful.

getSVONumberOfFrames()

int getSVONumberOfFrames

(

)

const

Gets the total number of frames in the SVO/OSF file.

Returns

The total number of frames, or -1 if not in playback mode.

getSVOPositionAtTimestamp()

int getSVOPositionAtTimestamp

(

sl::Timestamp

timestamp

)

const

Retrieves the frame index within the SVO/OSF file corresponding to the provided timestamp.

Parameters

timestamp

: The timestamp to search for (in nanoseconds).

Returns

The frame index closest to the given timestamp, or -1 if not in playback mode.

setTimestampBaseOffset()

void setTimestampBaseOffset

(

int64_t

offset

)

Sets the base timestamp offset for converting OSF sensor timestamps to Unix epoch.

OSF files store sensor-relative timestamps (nanoseconds since sensor boot). This method sets an offset that is added to OSF timestamps when returning frame timestamps via getTimestamp(IMAGE), and subtracted when seeking via getSVOPositionAtTimestamp().

This is used by Sensors::syncSVO() to align LiDAR timestamps with camera timestamps for multi-sensor synchronized playback.

Parameters

offset

: The offset in nanoseconds to add to OSF timestamps.

Note

This should be called after open() and before reading frames.

getTimestampBaseOffset()

int64_t getTimestampBaseOffset

(

)

const

Gets the base timestamp offset for OSF playback.

Returns

The current timestamp offset in nanoseconds.

pauseSVOReading()

void pauseSVOReading

(

bool

status

)

Pauses or resumes SVO/OSF reading.

Parameters

status

: If true, the reading is paused. If false, the reading is resumed.

Note

This is only relevant when InitLidarParameters::svo_real_time_mode is enabled.

close()

void close

(

)

Closes the Lidar.