Hydra: A Real-time Spatial Perception System for 3D Scene Graph Construction and Optimization

3D scene graphs have recently emerged as a powerful high-level representation of 3D environments. A 3D scene graph describes the environment as a layered graph where nodes represent spatial concepts at multiple levels of abstraction (from low-level geometry to high-level semantics including objects, places, rooms, buildings, etc.) and edges represent relations between concepts. While 3D scene graphs can serve as an advanced "mental model" for robots, how to build such a rich representation in real-time is still uncharted territory.