ResearchResearch paperRobotics & Embodied AI · Multimodal Models · Agents & Tool Use2 sources · Oct 13, 2026

Urbex: Agentic Spatial Grounding for City-Scale 3D Scenes

We propose Urbex, an agentic vision-language framework that instead casts grounding as active spatial search.

Key points

  • City-scale 3D grounding is commonly formulated as candidate ranking, which requires precomputed instance proposals and becomes inefficient in large outdoor scenes.
  • Urbex represents a city-scale 3D scene as an interactive multi-view environment, allowing a VLM agent to query landmarks, zoom into local regions, render oblique views, and commit a grounded bounding box.
  • We optimize this tool-use policy with reinforcement learning on CityRefer, using smooth localization rewards and lightweight shaping rewards for efficient exploration.
  • Zero-shot results on STPLS3D-Refer further indicate improved cross-scene robustness.

Sources (2)

Extractive summary: sentences quoted from the sources.

Before this

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  3. Oct 12, 2026Of Errors and Echoes: Responsibility-Aware Credit Assignment for Tool-Use Agents
  4. Oct 11, 2026A Sovereign, Indic-First, Reasoning Model
  5. Oct 11, 2026RSIPO: Recursive Self-Improving Policy Optimization for Agentic Reinforcement Learning via Skill-Policy Co-Evolution
  6. Oct 10, 2026Self-Evolving Visual Agent via Margin Reward

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