Omniverse Common Extension

Introduction

The Common extension is the one extension that every sensor extension depends on. It provides a set of common functionalities/headers that are used by other extensions.

Plugins

IDWPodIO

The IDWPodIO class is an interface for DW POD file format I/O operations. It writes and reads lidar bin files using the DW POD format.

Methods

• void init(const DWPodIOConfig& cfg)

  • Initializes the IDWPodIO interface with the given configuration.

• void dumpPacket(void* packet, const uint64_t packetSize, void* packetHeader, const uint64_t packetHeaderSize, const uint64_t packetTimestampNs)

  • Writes the given packet to the file.

• TimedDataBuffer readNextPacket()

  • Reads the next DWPod packet with a timestamp.

• const DWPodIOConfig& getCfg()

  • Returns the configuration of the IDWPodIO interface.

Initialization

To get an object of the IDWPodIO interface, you need to call the carb::getFramework()->acquireInterface<omni::sensors::IDWPodIOFactory>()->createInstance() function. To initialize the IDWPodIO interface, you need to create a DWPodIOConfig structure and call the init method.

import omni.sensors.nv.common._common as common

pod_cfg = common.DWPodIOConfig()
pod_cfg.accessType = common.DWPodAccessType.READ
pod_cfg.fileName = cfg.cfg.fileName
factory = common.acquire_dwpod_io_interface()
dwpod_io = factory.createInstance()

dwpod_io.init(pod_cfg)

DWPodIOConfig

The DWPodIOConfig structure is used to configure the IDWPodIO interface.

• DWPodAccessType accessType

  • The access type for the IDWPodIO interface. Default is DWPodAccessType::WRITE.

• TimedDataBuffer trackHeaderDataBuffer

  • The track data header for the file.

• omni::string fileName

  • The name of the file. Default is an empty string.

• int desiredTrackId

  • Specifies which track to read from the file. Default is 1.

DWPodAccessType

The DWPodAccessType enumeration specifies whether the DWPodIOConfig is reading or writing to a file.

• READ

  • The access type for the DWPodIOConfig for file reading.

• WRITE

  • The access type for the DWPodIOConfig for file writing.

TimedDataBuffer

The TimedDataBuffer contains the raw data and the timestamp of the buffer.

• int64_t timestampNs

  • The timestamp of the data buffer in nanoseconds.

• omni::vector<uint8_t> dataBuffer

  • The raw data buffer.

IProfileReader

The IProfileReader reads the parameter of the modality specific profile from a JSON file. The code below details how to instantiate the IProfileReader interface

import omni.sensors.nv.common._common as common

profilefactory = common.acquire_profile_reader_interface()

Users can create objects that implement this interface by acquiring the IProfileReader carbonite interface and using the acquire_profile_reader_interface() method.

Instantiation

To instantiate the IProfileReader the user needs to acquire the carbonite IProfileReaderFactory interface through the python bindings interface:

profilefactory = common.acquire_profile_reader_interface()

Initialization

The user has to initialize the profile reader with the JSON string

import omni.sensors.nv.common._common as common

profilefactory = common.acquire_profile_reader_interface()
reader = profilefactory.createInstance()
reader.init(data, common.ProfileType.LIDAR)

The supprted profile types are: LIDAR, RADAR, USS, IDS (and variants)

Filling a Profile object

The user can get the data size object of the profile (for data dependent sizes, e.g, for LIDAR) and has to allocate the memory for the profile objectId before the profile reader can fill the profile object

import omni.sensors.nv.common._common as common

profilefactory = common.acquire_profile_reader_interface()

with open(profilfilename, "r") as file:
    data = file.read()
    reader = profilefactory.createInstance()
    reader.init(data, common.ProfileType.LIDAR)
    data_size = reader.dataSizeProfile()
    byte_array = bytearray(data_size)
    reader.update(byte_array)
    profile = lidar.getLidarProfileFromBuffer(byte_array)

Python Bindings

The common extension provides a multitude of python bindings, e.g., for the IProfileReader and IDWPodIO interfaces.