iARCS: Iterative Agentic RL for Controllable 3D Scene Generation
Existing 3D scene generation methods struggle to reliably satisfy task-critical functional constraints such as navigability and reachability, limiting the practical utility of synthetic data. This work proposes an iterative agent-based reinforcement learning framework that first enhances physical plausibility and layout quality through pretraining with generic rewards, then leverages a large language model (LLM) to generate executable, task-specific reward programs. These LLM-generated rewards are integrated into a feedback-driven reinforcement learning loop for iterative refinement. By uniquely combining LLM-synthesized reward functions with iterative reinforcement learning, the approach significantly improves adherence to functional constraints while preserving scene diversity, thereby enhancing downstream task performance.