OrbbecSDK is a cross-platform C/C++ software development kit for Orbbec 3D cameras, supporting depth, color, infrared, and IMU sensors. It provides both a high-level Pipeline API for easy stream management and a low-level Device/Sensor API for fine-grained control. The architecture is library-based with a C API (ObSensor.h) and a C++ wrapper (ObSensor.hpp), following a consistent pattern of context creation, device enumeration, stream configuration, frame acquisition, and post-processing via composable filters. Key entry points include Context (device discovery), Pipeline (streaming), Device (property control), and Filter (alignment, point cloud generation, noise removal, etc.). Data flows involve configuring stream profiles, starting the pipeline, receiving frames (depth, color, IR, IMU), applying filters (e.g., depth-to-color alignment, HDR merge, spatial/temporal filtering), and optionally recording or replaying streams. External dependencies include OpenCV for example visualizations, cJSON for multi-device synchronization configuration, and platform-specific USB drivers. The SDK is used in robotics, AR/VR, industrial inspection, and 3D scanning applications.