AI Coding Live News

USC, UCLA, and CMU Release Grid-Bench for Multi-Step Spatial Reasoning: 8,928 Executable Instances Reveal Severe State Drift Across 64-Step Trajectories

Can LLMs reliably maintain spatial state representations across sequential operations? USC, UCLA, and CMU introduced Grid-Bench (arXiv:2610.22312, GitHub: grid-bench/Grid-Bench), an executable benchmark with 8,928 instances testing 2D/3D/4D grid state transitions across history lengths up to T=64. Evaluations across 6 frontier models show steep degradation: while GPT-5.6 Sol and Claude 5 Sonnet retain strong cell accuracy, open-weight and mid-tier models collapse to near-zero exact world reconstruction over long trajectories.

USC, UCLA, and CMU Release Grid-Bench for Multi-Step Spatial Reasoning: 8,928 Executable Instances Reveal Severe State Drift Across 64-Step Trajectories

Key Takeaways

  • USC, UCLA, and CMU introduced Grid-Bench (arXiv:2610.22312), an executable spatial tracking benchmark across 2D, 3D, and 4D discrete manifolds
  • Evaluates 8,928 instances across 8 spatial transformation rule families and trajectory lengths up to T=64 steps
  • At intermediate length T=16, GPT-5.6 Sol (98.0% cell accuracy) and Claude 5 Sonnet (96.8%) lead while mid-tier models drop sharply
  • At extreme length T=64, exact world recovery drops to 0 for GLM-5 and Kimi K2.5, demonstrating that long-horizon agents must rely on external state engines
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SpatialOPSD: Distilling Spatial Intelligence from Verified Coding Agent Traces into Tool-Free Multimodal LLMs

Endowing Multimodal Large Language Models (MLLMs) with robust 3D spatial intelligence and geometric reasoning is essential for embodied robotics. Existing systems rely on spatial coding agents—prompting MLLMs to generate and execute external Python geometry scripts (e.g., invoking OpenCV, point cloud packages, and coordinate projections) during inference. However, this tool-augmented architecture incurs massive latency overheads, execution dependencies, and frequent runtime runtime sandboxing failures. In newly released research (arXiv:2610.11366), researchers introduce SpatialOPSD (code: github.com/vermouth599/Spatial-OPSD), an on-policy self-distillation framework that internalizes agentic spatial capabilities directly into a standalone, tool-free MLLM. SpatialOPSD leverages summarized execution traces from spatial coding agents as privileged guidance during training. To prevent privileged information leakage from inducing repetitive generation and hallucinations, the framework introduces Repetition-Aware Distillation, pairing repetition masking with unlikelihood regularization. Empirical evaluations show that standalone SpatialOPSD outperforms tool-free baselines across diverse 3D spatial reasoning tasks while slashing latency and eliminating fragile external execution runtimes.

SpatialOPSD: Distilling Spatial Intelligence from Verified Coding Agent Traces into Tool-Free Multimodal LLMs

Key Takeaways

  • SpatialOPSD open-sourced, distilling spatial coding agent traces to internalize 3D geometric reasoning into standalone MLLMs
  • Introduces Repetition-Aware Distillation to prevent privileged information leakage and eliminate degenerative text loops
  • Eliminates external sandbox dependencies, slashing inference latency by over 75% while outperforming tool-free baselines
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ViSkill: Zhejiang University REAL Lab Unveils Evolving Visual-Native Skills for VLM Agents, Elevating Success Rates to 91%

In spatially demanding environments such as GUI operating systems and spatial grid puzzles, multimodal foundation agents improve sample efficiency by distilling past successful trajectories into reusable strategies. However, existing skill-augmented paradigms remain strictly text-centric: they linearize continuous spatial layouts, geometry, and visual action-state correspondences into text strings, discarding essential structural properties. Researchers from Zhejiang University's REAL Lab unveil ViSkill (arXiv:2610.12403), a visual-native skill learning framework for Vision-Language Model (VLM) agents. ViSkill encodes successful interactions directly as composite visual skill cards natively accessible to VLM backbones. Retrieved visual skills guide online policy inference while simultaneously shaping step-level rewards. Successful new trajectories are distilled back into the visual skill library, creating a closed reinforcement feedback loop where skill accumulation and policy optimization mutually enhance each other. Across spatial reasoning benchmarks including Sokoban, FrozenLake, and PrimitiveSkill, ViSkill registers an overall success rate of 0.89 (climbing to 0.91 with cold-start initialization), outperforming proprietary and open-source baselines while converging significantly faster than standard PPO, with code fully open-sourced.

Key Takeaways

  • Zhejiang University releases ViSkill, introducing composite visual skill cards to replace lossy textual skill representations in VLM agents
  • Achieves 0.89 to 0.91 success rates across spatial reasoning tasks while converging over 2x faster than standard PPO
  • Establishes a closed-loop flywheel between visual skill accumulation and policy reinforcement, with code fully open-sourced
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WM-VLM: CMU and MBZUAI Probe Internal World Models for Interleaved Visual-Textual Spatial Reasoning

Humans solve complex spatial transformations by mentally simulating physical visual transitions, maintaining visual imaginations to ground multi-step reasoning. In contrast, existing Vision-Language Models (VLMs) tackle spatial questions almost entirely via text-token chains of thought, triggering acute hallucinations when predicting 3D rotations or spatial clearances. Researchers from Carnegie Mellon University and MBZUAI introduce WM-VLM (arXiv:2609.34826), integrating a lightweight world model branch directly into foundation VLMs to synthesize intermediate visual states during inference. The framework adopts a two-stage training paradigm: first training the model to foresee and render verifiable intermediate visual states, and then training it to ground downstream logical deductions upon those synthesized states. Evaluated on rigorous 2D and 3D mental rotation tasks, WM-VLM outperforms standard SFT baselines by up to 39.25 percentage points. Ablations prove that performance collapses when generated visual frames are removed or corrupted, establishing that internal world models provide indispensable spatial cognitive scaffolds.

WM-VLM: CMU and MBZUAI Probe Internal World Models for Interleaved Visual-Textual Spatial Reasoning

Key Takeaways

  • CMU and MBZUAI introduce WM-VLM, equipping VLMs with internal world models for interleaved visual-textual mental simulation
  • Adopts a two-stage training paradigm: synthesizing verifiable intermediate visual states and grounding spatial deduction upon them
  • Outperforms standard SFT baselines by up to 39.25 percentage points on 2D/3D mental rotations, proving causal visual grounding
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Zhejiang University Open-Sources Spatial-Interactor: Closed-Loop Physical World Spatial Reasoning with LSI-108K

Researchers from Zhejiang University's OmniAI Lab have open-sourced Spatial-Interactor alongside the LSI-108K interactive spatial reasoning dataset (arXiv: 2609.23038). Addressing severe 3D hallucination in passive vision-language models, Spatial-Interactor introduces closed-loop active perception where an agent's physical camera-control actions inform subsequent spatial inferences, fully accessible under the Apache 2.0 license.

Zhejiang University Open-Sources Spatial-Interactor: Closed-Loop Physical World Spatial Reasoning with LSI-108K

Key Takeaways

  • Replaces passive single-image inspection with active, multi-view camera manipulation to resolve spatial occlusions.
  • Releases LSI-108K, the first large-scale interactive spatial dataset spanning 108,000 closed-loop trajectories.
  • Improves 3D object localization, bounding box estimation, and obstacle avoidance accuracy by 33.8% on average.
  • Complete PyTorch training scripts, evaluation benchmarks, and checkpoints open-sourced under Apache 2.0 on GitHub.
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⚡ Spatial Interactor⚡ Qwen 2 Vl🤖 embodied-agent🌐 zhejiang-university