PISA Experiments: Exploring Physics Post-Training for Video Diffusion Models by Watching Stuff Drop
On the map: Diffusion models → Video generation
Abstract (arXiv)
Large-scale pre-trained video generation models excel in content creation but are not reliable as physically accurate world simulators out of the box. This work studies the process of post-training these models for accurate world modeling through the lens of the simple, yet fundamental, physics task of modeling object freefall. We show state-of-the-art video generation models struggle with this basic task, despite their visually impressive outputs. To remedy this problem, we find that fine-tuning on a relatively small amount of simulated videos is effective in inducing the dropping behavior in the model, and we can further improve results through a novel reward modeling procedure we introduce. Our study also reveals key limitations of post-training in generalization and distribution modeling. Additionally, we release a benchmark for this task that may serve as a useful diagnostic tool for tracking physical accuracy in large-scale video generative model development.
Key facts. Cited by 49 papers in the map (data through 7 Oct 2026). Placed in Video generation, one of 14 directions in Diffusion models. Builds on 26 of its 44 references that are in the map. First posted on arXiv 12 Mar 2025.
Builds on
26 of 44 references.
Closest ancestors · 4
Same direction, newest first
- 2024Pyramidal Flow Matching for Efficient Video Generative Modeling8 Oct
- 2024CogVideoX: Text-to-Video Diffusion Models with An Expert Transformer12 Aug
- 2024Video Diffusion Alignment via Reward Gradients11 Jul
- 2023DynamiCrafter: Animating Open-domain Images with Video Diffusion Priors18 Oct
Other references · 22
- 2022Flow Straight and Fast: Learning to Generate and Transfer Data with Rectified Flowcited by 3,550
- 2016Improved Techniques for Training GANscited by 2,938
- 2024SAM 2: Segment Anything in Images and Videoscited by 2,784
- 2020RAFT: Recurrent All-Pairs Field Transforms for Optical Flowcited by 2,385
- 2023VBench: Comprehensive Benchmark Suite for Video Generative Modelscited by 1,755
- 2019Dream to Control: Learning Behaviors by Latent Imaginationcited by 1,598
- 2024Depth Anything V2cited by 1,385
- 2018Towards Accurate Generative Models of Video: A New Metric & Challengescited by 1,204
- 2023Mastering Diverse Domains through World Modelscited by 1,193
- 2025Cosmos World Foundation Model Platform for Physical AIcited by 833
- 2018Recurrent World Models Facilitate Policy Evolutioncited by 761
- 2024Open-Sora: Democratizing Efficient Video Production for Allcited by 637
10 more
- 2022Google Scanned Objects: A High-Quality Dataset of 3D Scanned Household Itemscited by 601
- 2023Learning Interactive Real-World Simulatorscited by 440
- 2015Unsupervised Learning of Video Representations using LSTMscited by 434
- 2022Kubric: A scalable dataset generatorcited by 373
- 2024VideoPhy: Evaluating Physical Commonsense for Video Generationcited by 215
- 2024How Far is Video Generation from World Model: A Physical Law Perspectivecited by 204
- 2024Towards World Simulator: Crafting Physical Commonsense-Based Benchmark for Video Generationcited by 167
- 2021Physion: Evaluating Physical Prediction from Vision in Humans and Machinescited by 145
- 2024Video as the New Language for Real-World Decision Makingcited by 86
- 2016Visual Dynamics: Probabilistic Future Frame Synthesis via Cross Convolutional Networkscited by 46
Built on by
Citing papers per year: 2025: 20; 2026: 29.
49 papers.
Sort:
By area:
- 2025Force Prompting: Video Generation Models Can Learn and Generalize Physics-based Control Signalscited by 51
- 2025NewtonGen: Physics-Consistent and Controllable Text-to-Video Generation via Neural Newtonian Dynamicscited by 40
- 2026Solaris: Building a Multiplayer Video World Model in Minecraftcited by 38
- 2025Exploring the Evolution of Physics Cognition in Video Generation: A Surveycited by 31
- 2025What about gravity in video generation? Post-Training Newton's Laws with Verifiable Rewardscited by 23
- 2025Epipolar Geometry Improves Video Generation Modelscited by 22
- 2025Hierarchical Fine-grained Preference Optimization for Physically Plausible Video Generationcited by 20
- 2026VGGRPO: Towards World-Consistent Video Generation with 4D Latent Rewardcited by 19
- 2025TiViBench: Benchmarking Think-in-Video Reasoning for Video Generative Modelscited by 18
- 2025Simulating the Visual World with Artificial Intelligence: A Roadmapcited by 15
- 2026PhysRVG: Physics-Aware Unified Reinforcement Learning for Video Generative Modelscited by 15
- 2026Self-Refining Video Samplingcited by 14
37 more
- 2025Enhancing Physical Plausibility in Video Generation by Reasoning the Implausibilitycited by 13
- 2026WorldBench: Benchmarking Physical Understanding of World Models by Isolating Physics Conceptscited by 12
- 2026Physical Simulator In-the-Loop Video Generationcited by 12
- 2025ProPhy: Progressive Physical Alignment for Dynamic World Simulationcited by 11
- 2025PhysMaster: Mastering Physical Representation for Video Generation via Reinforcement Learningcited by 10
- 20254DWorldBench: A Comprehensive Evaluation Framework for 3D/4D World Generation Modelscited by 10
- 2026Gamma-World: Generative Multi-Agent World Modeling Beyond Two Playerscited by 10
- 2026Goal Force: Teaching Video Models To Accomplish Physics-Conditioned Goalscited by 9
- 2026PhysInOne: Visual Physics Learning and Reasoning in One Suitecited by 9
- 2026ACWM-Phys: Investigating Generalized Physical Interaction in Action-Conditioned Video World Modelscited by 9
- 2026VideoCoCo: Code-as-CoT for Physically-Consistent Video Generation via an Agentic Dual-Engine Systemcited by 7
- 2025Planning with Sketch-Guided Verification for Physics-Aware Video Generationcited by 6
- 2025MoReGen: Multi-Agent Motion-Reasoning Engine for Code-based Text-to-Video Synthesiscited by 5
- 2026PhyCo: Learning Controllable Physical Priors for Generative Motioncited by 5
- 2025Cloning Deterministic Worlds: The Critical Role of Latent Geometry in Long-Horizon World Modelscited by 3
- 2025SeeU: Seeing the Unseen World via 4D Dynamics-aware Generationcited by 3
- 2025Over++: Generative Video Compositing for Layer Interaction Effectscited by 3
- 2026YoCausal: How Far is Video Generation from World Model? A Causality Perspectivecited by 3
- 2026Learning Explicit Physical Parameter Control and Benchmarking for Video Generationcited by 3
- 2026GAUGE: A Measurement-Grounded Benchmark for Physical Fidelity in Simulation Engines and Video World Modelscited by 3
- 2025Learning to Generate Rigid Body Interactions with Video Diffusion Modelscited by 2
- 2025VDAWorld: World Modelling via VLM-Directed Abstraction and Simulationcited by 2
- 2026PhysEditWorld: A Large-Scale Dataset Toward Physics-Editable World Modelscited by 2
- 2025PhysFire-WM: A Physics-Informed World Model for Emulating Fire Spread Dynamicscited by 1
- 2026Seeking Physics in Diffusion Noisecited by 1
- 2026DiReCT: Disentangled Regularization of Contrastive Trajectories for Physics-Refined Video Generationcited by 1
- 2026Physics Question Scene Graph: Fine-grained Evaluation of Physical Plausibility in Text-to-Video Generationcited by 1
- 2026NewtPhys: Do Foundation Models Understand Newtonian Physics?cited by 0
- 2026PhysRAG: Enhancing Physics-Awareness in Video Generation via Retrieval-Augmented Generationcited by 0
- 2026DeforM: Reasoning-Guided Physics-Aware Video Generation via Spatial-Temporal Maskingcited by 0
- 2026Diagnosing Under-Development of Irreversible Processes in Video Generationcited by 0
- 2026RigidBench: Evaluating Rigid-Body Physics in Video Generation Modelscited by 0
- 2026Principia: Relational Physics Tests for Video Modelscited by 0
- 2026PhysWeep: Does a Video Generator Realize the Physics You Ask For?cited by 0
- 2026MultiEcho: An Experimental Science of Learned Worldscited by 0
- 2026HiPhy: Hierarchical Alignment for Physically-Plausible Multi-Principle Video Generationcited by 0
- 2026Fluid-Gen-Zero: Grounding Pretrained Video Generators in Physics without Trainingcited by 0
- 2026Fluid-Gen-Zero: Grounding Pretrained Video Generators in Physics without Training7 Oct 2026
- 2026HiPhy: Hierarchical Alignment for Physically-Plausible Multi-Principle Video Generation1 Oct 2026
- 2026MultiEcho: An Experimental Science of Learned Worlds27 Sep 2026
- 2026PhysWeep: Does a Video Generator Realize the Physics You Ask For?5 Sep 2026
- 2026Principia: Relational Physics Tests for Video Models3 Sep 2026
- 2026RigidBench: Evaluating Rigid-Body Physics in Video Generation Models16 Aug 2026
- 2026GAUGE: A Measurement-Grounded Benchmark for Physical Fidelity in Simulation Engines and Video World Models6 Aug 2026
- 2026Diagnosing Under-Development of Irreversible Processes in Video Generation1 Aug 2026
- 2026VideoCoCo: Code-as-CoT for Physically-Consistent Video Generation via an Agentic Dual-Engine System29 Jul 2026
- 2026Learning Explicit Physical Parameter Control and Benchmarking for Video Generation21 Jul 2026
- 2026DeforM: Reasoning-Guided Physics-Aware Video Generation via Spatial-Temporal Masking21 Jul 2026
- 2026PhysRAG: Enhancing Physics-Awareness in Video Generation via Retrieval-Augmented Generation25 Jun 2026
37 more
- 2026PhysEditWorld: A Large-Scale Dataset Toward Physics-Editable World Models25 Jun 2026
- 2026Physics Question Scene Graph: Fine-grained Evaluation of Physical Plausibility in Text-to-Video Generation24 Jun 2026
- 2026NewtPhys: Do Foundation Models Understand Newtonian Physics?2 Jun 2026
- 2026YoCausal: How Far is Video Generation from World Model? A Causality Perspective28 May 2026
- 2026Gamma-World: Generative Multi-Agent World Modeling Beyond Two Players27 May 2026
- 2026ACWM-Phys: Investigating Generalized Physical Interaction in Action-Conditioned Video World Models9 May 2026
- 2026PhyCo: Learning Controllable Physical Priors for Generative Motion30 Apr 2026
- 2026PhysInOne: Visual Physics Learning and Reasoning in One Suite10 Apr 2026
- 2026VGGRPO: Towards World-Consistent Video Generation with 4D Latent Reward27 Mar 2026
- 2026DiReCT: Disentangled Regularization of Contrastive Trajectories for Physics-Refined Video Generation26 Mar 2026
- 2026Seeking Physics in Diffusion Noise15 Mar 2026
- 2026Physical Simulator In-the-Loop Video Generation6 Mar 2026
- 2026Solaris: Building a Multiplayer Video World Model in Minecraft25 Feb 2026
- 2026WorldBench: Benchmarking Physical Understanding of World Models by Isolating Physics Concepts29 Jan 2026
- 2026Self-Refining Video Sampling26 Jan 2026
- 2026PhysRVG: Physics-Aware Unified Reinforcement Learning for Video Generative Models16 Jan 2026
- 2026Goal Force: Teaching Video Models To Accomplish Physics-Conditioned Goals9 Jan 2026
- 2025Over++: Generative Video Compositing for Layer Interaction Effects22 Dec 2025
- 2025PhysFire-WM: A Physics-Informed World Model for Emulating Fire Spread Dynamics19 Dec 2025
- 2025VDAWorld: World Modelling via VLM-Directed Abstraction and Simulation11 Dec 2025
- 2025ProPhy: Progressive Physical Alignment for Dynamic World Simulation5 Dec 2025
- 2025MoReGen: Multi-Agent Motion-Reasoning Engine for Code-based Text-to-Video Synthesis3 Dec 2025
- 2025SeeU: Seeing the Unseen World via 4D Dynamics-aware Generation3 Dec 2025
- 2025What about gravity in video generation? Post-Training Newton's Laws with Verifiable Rewards29 Nov 2025
- 20254DWorldBench: A Comprehensive Evaluation Framework for 3D/4D World Generation Models25 Nov 2025
- 2025Planning with Sketch-Guided Verification for Physics-Aware Video Generation21 Nov 2025
- 2025TiViBench: Benchmarking Think-in-Video Reasoning for Video Generative Models17 Nov 2025
- 2025Simulating the Visual World with Artificial Intelligence: A Roadmap11 Nov 2025
- 2025Cloning Deterministic Worlds: The Critical Role of Latent Geometry in Long-Horizon World Models30 Oct 2025
- 2025Epipolar Geometry Improves Video Generation Models24 Oct 2025
- 2025PhysMaster: Mastering Physical Representation for Video Generation via Reinforcement Learning15 Oct 2025
- 2025Learning to Generate Rigid Body Interactions with Video Diffusion Models2 Oct 2025
- 2025Enhancing Physical Plausibility in Video Generation by Reasoning the Implausibility29 Sep 2025
- 2025NewtonGen: Physics-Consistent and Controllable Text-to-Video Generation via Neural Newtonian Dynamics25 Sep 2025
- 2025Hierarchical Fine-grained Preference Optimization for Physically Plausible Video Generation14 Aug 2025
- 2025Force Prompting: Video Generation Models Can Learn and Generalize Physics-based Control Signals26 May 2025
- 2025Exploring the Evolution of Physics Cognition in Video Generation: A Survey27 Mar 2025
- 2025Force Prompting: Video Generation Models Can Learn and Generalize Physics-based Control Signalscited by 51
- 2026Solaris: Building a Multiplayer Video World Model in Minecraftcited by 38
- 2025Simulating the Visual World with Artificial Intelligence: A Roadmapcited by 15
- 2026WorldBench: Benchmarking Physical Understanding of World Models by Isolating Physics Conceptscited by 12
- 2025PhysMaster: Mastering Physical Representation for Video Generation via Reinforcement Learningcited by 10
- 20254DWorldBench: A Comprehensive Evaluation Framework for 3D/4D World Generation Modelscited by 10
- 2026Gamma-World: Generative Multi-Agent World Modeling Beyond Two Playerscited by 10
- 2026Goal Force: Teaching Video Models To Accomplish Physics-Conditioned Goalscited by 9
- 2026ACWM-Phys: Investigating Generalized Physical Interaction in Action-Conditioned Video World Modelscited by 9
- 2025Cloning Deterministic Worlds: The Critical Role of Latent Geometry in Long-Horizon World Modelscited by 3
- 2026YoCausal: How Far is Video Generation from World Model? A Causality Perspectivecited by 3
- 2026GAUGE: A Measurement-Grounded Benchmark for Physical Fidelity in Simulation Engines and Video World Modelscited by 3
12 most cited of 16 All 16 (JSON)
- 2026MultiEcho: An Experimental Science of Learned Worlds27 Sep 2026
- 2026GAUGE: A Measurement-Grounded Benchmark for Physical Fidelity in Simulation Engines and Video World Models6 Aug 2026
- 2026PhysEditWorld: A Large-Scale Dataset Toward Physics-Editable World Models25 Jun 2026
- 2026YoCausal: How Far is Video Generation from World Model? A Causality Perspective28 May 2026
- 2026Gamma-World: Generative Multi-Agent World Modeling Beyond Two Players27 May 2026
- 2026ACWM-Phys: Investigating Generalized Physical Interaction in Action-Conditioned Video World Models9 May 2026
- 2026Solaris: Building a Multiplayer Video World Model in Minecraft25 Feb 2026
- 2026WorldBench: Benchmarking Physical Understanding of World Models by Isolating Physics Concepts29 Jan 2026
- 2026Goal Force: Teaching Video Models To Accomplish Physics-Conditioned Goals9 Jan 2026
- 2025PhysFire-WM: A Physics-Informed World Model for Emulating Fire Spread Dynamics19 Dec 2025
- 2025VDAWorld: World Modelling via VLM-Directed Abstraction and Simulation11 Dec 2025
- 20254DWorldBench: A Comprehensive Evaluation Framework for 3D/4D World Generation Models25 Nov 2025
12 newest of 16 All 16 (JSON)
- 2025Exploring the Evolution of Physics Cognition in Video Generation: A Surveycited by 31
- 2025What about gravity in video generation? Post-Training Newton's Laws with Verifiable Rewardscited by 23
- 2025Epipolar Geometry Improves Video Generation Modelscited by 22
- 2026VGGRPO: Towards World-Consistent Video Generation with 4D Latent Rewardcited by 19
- 2025Enhancing Physical Plausibility in Video Generation by Reasoning the Implausibilitycited by 13
- 2026Physical Simulator In-the-Loop Video Generationcited by 12
- 2026PhyCo: Learning Controllable Physical Priors for Generative Motioncited by 5
- 2025Learning to Generate Rigid Body Interactions with Video Diffusion Modelscited by 2
- 2026Seeking Physics in Diffusion Noisecited by 1
- 2026DiReCT: Disentangled Regularization of Contrastive Trajectories for Physics-Refined Video Generationcited by 1
- 2026PhyCo: Learning Controllable Physical Priors for Generative Motion30 Apr 2026
- 2026VGGRPO: Towards World-Consistent Video Generation with 4D Latent Reward27 Mar 2026
- 2026DiReCT: Disentangled Regularization of Contrastive Trajectories for Physics-Refined Video Generation26 Mar 2026
- 2026Seeking Physics in Diffusion Noise15 Mar 2026
- 2026Physical Simulator In-the-Loop Video Generation6 Mar 2026
- 2025What about gravity in video generation? Post-Training Newton's Laws with Verifiable Rewards29 Nov 2025
- 2025Epipolar Geometry Improves Video Generation Models24 Oct 2025
- 2025Learning to Generate Rigid Body Interactions with Video Diffusion Models2 Oct 2025
- 2025Enhancing Physical Plausibility in Video Generation by Reasoning the Implausibility29 Sep 2025
- 2025Exploring the Evolution of Physics Cognition in Video Generation: A Survey27 Mar 2025
- 2025NewtonGen: Physics-Consistent and Controllable Text-to-Video Generation via Neural Newtonian Dynamicscited by 40
- 2026PhysRVG: Physics-Aware Unified Reinforcement Learning for Video Generative Modelscited by 15
- 2026Self-Refining Video Samplingcited by 14
- 2025ProPhy: Progressive Physical Alignment for Dynamic World Simulationcited by 11
- 2026PhysInOne: Visual Physics Learning and Reasoning in One Suitecited by 9
- 2025Planning with Sketch-Guided Verification for Physics-Aware Video Generationcited by 6
- 2025SeeU: Seeing the Unseen World via 4D Dynamics-aware Generationcited by 3
- 2025Over++: Generative Video Compositing for Layer Interaction Effectscited by 3
- 2026Learning Explicit Physical Parameter Control and Benchmarking for Video Generationcited by 3
- 2026Physics Question Scene Graph: Fine-grained Evaluation of Physical Plausibility in Text-to-Video Generationcited by 1
- 2026NewtPhys: Do Foundation Models Understand Newtonian Physics?cited by 0
- 2026DeforM: Reasoning-Guided Physics-Aware Video Generation via Spatial-Temporal Maskingcited by 0
12 most cited of 18 All 18 (JSON)
- 2026Fluid-Gen-Zero: Grounding Pretrained Video Generators in Physics without Training7 Oct 2026
- 2026HiPhy: Hierarchical Alignment for Physically-Plausible Multi-Principle Video Generation1 Oct 2026
- 2026PhysWeep: Does a Video Generator Realize the Physics You Ask For?5 Sep 2026
- 2026Principia: Relational Physics Tests for Video Models3 Sep 2026
- 2026RigidBench: Evaluating Rigid-Body Physics in Video Generation Models16 Aug 2026
- 2026Diagnosing Under-Development of Irreversible Processes in Video Generation1 Aug 2026
- 2026Learning Explicit Physical Parameter Control and Benchmarking for Video Generation21 Jul 2026
- 2026DeforM: Reasoning-Guided Physics-Aware Video Generation via Spatial-Temporal Masking21 Jul 2026
- 2026Physics Question Scene Graph: Fine-grained Evaluation of Physical Plausibility in Text-to-Video Generation24 Jun 2026
- 2026NewtPhys: Do Foundation Models Understand Newtonian Physics?2 Jun 2026
- 2026PhysInOne: Visual Physics Learning and Reasoning in One Suite10 Apr 2026
- 2026Self-Refining Video Sampling26 Jan 2026
12 newest of 18 All 18 (JSON)
Similar, not cited
Close in wording, no citation either way
- 2025Show Me: Unifying Instructional Image and Video Generation with Diffusion Models
- 2024AVID: Adapting Video Diffusion Models to World Models
- 2026Physics-IQ Verified
- 2026PhyGround: Benchmarking Physical Reasoning in Generative World Models
- 2025Physics-Guided Motion Loss for Video Generation Model
- 2026Does Physics Live in the Activations? Localizing Physical Quantities in Video Diffusion Models
- 2022Video Diffusion Models
- 2025LikePhys: Evaluating Intuitive Physics Understanding in Video Diffusion Models via Likelihood Preference