SPEAR: A Simulator for Photorealistic Embodied AI Research

SPEAR is a Python library that connects to and programmatically controls Unreal Engine applications through a modular plugin architecture. The paper reports access to more than 14,000 Unreal Engine functions, 1920×1080 photorealistic rendering at 73 FPS directly into NumPy arrays, and ground-truth modalities such as material IDs, non-diffuse intrinsic decomposition, and physically based shading parameters. SPEAR also provides a high-level graph programming model for deterministic execution of tasks with arbitrary data dependencies within a single Unreal Engine frame. Demonstrations cover embodied agents, city-scale rendering, procedural generation, synchronized face views, MuJoCo co-simulation, and natural-language scene editing.