University of Pennsylvania · Fall 2026

World Models

This course introduces world models—learned representations and predictors of environment dynamics for perception, planning, and decision making. We study how they support control and reasoning across reinforcement learning, video and 3D, multimodal agents, and robotics.

Instructor
Jiatao Gu ↗
Time
Tuesdays & Thursdays · 12:00–1:29 PM
Room
AGH 105A & 105B ↗
Instructor office hours
Thursdays · 4:30–5:30 PM · AGH 423
Section
001 · CRN 90075

What is next

Course staff

Meet the instructional team. Instructor office hours are Thursdays, 4:30–5:30 PM in AGH 423.

TA office hours: Please see Ed Discussion for schedules, locations, and online meeting links.

Tentative Schedule

21 lectures, one special topic, one invited lecture, one final project presentation, and one final exam, plus four confirmed no-class dates and one tentative cancellation, following the Penn academic calendar. Assignment and project deadlines are collected under Coursework. Slides and readings appear here as the semester goes on.

Representation, prediction, and interaction are recurring themes, not sequential phases. Later application units—including 3D and robotics—bring these questions back together.

Download course calendar (.ics) ↓
  • Latent World ModelsL3–L10
  • Generative & Video ModelsL11–L14
  • Spatial & Physical ModelsL15–L17
  • Robotics & AgentsL18–L20
  1. 01

    World Models: An Overview

    Observation, state, transition, memory, action, prediction, simulation, planning, and reasoning.

    Slides (PDF)
    Lecture 1
  2. 02

    World Models: History, Foundations, and Probabilistic Formulation

    Trajectory distributions, latent state, partial observability, and one-step versus rollout objectives.

    Lecture 2
  3. 03

    Environments, Simulators, and Rollouts

    Environment interfaces, known transition rules, reset and step, observations, actions, feedback, and trajectory collection.

    Lecture 3
  4. 04

    State-Space Models

    Transition and emission models, filtering, smoothing, observability, and belief-state inference.

    Lecture 4
  5. 05

    Self-supervised Representation Learning I

    What representations preserve, how probes test them, and how reconstruction, masked prediction, autoregressive prediction, and contrastive objectives shape features.

    Lecture 5
  6. 06

    Self-supervised Representation Learning II

    Joint-embedding prediction, target encoders, masked latent prediction, and action-conditioned extensions.

    Lecture 6
  7. 07

    Latent-Variable and Adversarial Models

    Held virtually via Zoom. VAEs, the ELBO, posterior collapse, GANs, and explicit versus implicit generation.

    Lecture 7Zoom
  8. —

    Tentative — No class

    Class is tentatively canceled due to urgent instructor travel. Confirmation will be posted on Canvas.

    Tentative
  9. 08

    Latent World Models

    Tentative format change: virtual via Zoom; the link will be posted on Canvas. Autoregressive prediction, history and action conditioning, training versus rollout, and the World Models (2018) system.

    Slides (PDF)
    Lecture 8ZoomTentative
  10. 09

    Planning and Control with World Models

    Held virtually via Zoom. Planning from LGSSMs to learned latent dynamics; MPC, CEM, MPPI, gradient-based action optimization, and planning limitations.

    Slides (PDF)
    Lecture 9Zoom
  11. 10

    Policy and Value Learning with World Models

    L6–L9 revisit: representation learning, latent prediction, LeWM, RSSM, and CEM, followed by an introduction to policy and value learning with Dreamer.

    Slides (PDF)
    Lecture 10
  12. —

    No class — Fall Term Break

    University break.

  13. —

    No class — COLM 2026

    Instructor conference travel.

  14. —

    No class — COLM 2026

    Instructor conference travel.

  15. 11

    Dreamer, Diffusion and Flow Matching

    Dreamer policy and value learning from imagined experience, VAE-to-diffusion foundations, DDIM, and flow matching.

    Slides (PDF)
    Lecture 11
  16. 12

    Video Diffusion Models

    DDIM, flow matching, guidance, U-Net and DiT architectures, latent and pixel generation, and bidirectional text-to-video and image-to-video models.

    Slides (PDF)
    Lecture 12
  17. 13

    Video World Models and Fast Sampling

    Joint video generation, spatial-temporal attention, action-conditioned autoregressive video, teacher forcing and diffusion forcing, flow maps, BOOT, pi-Flow, consistency, and MeanFlow.

    Slides (PDF)
    Lecture 13
  18. 14

    Fast Sampling and Interactive World Models

    Flow maps, BOOT, pi-Flow, consistency and MeanFlow; distribution matching with DMD, Drifting, and FD-Loss; autoregressive video rollouts, Self Forcing, Causal Forcing, and Self-Forcing++.

    Slides (PDF)
    Lecture 14
  19. 15

    Special Topic: Are Normalizing Flows Good Candidates for World Models?

    Normalizing flows as generative models and candidates for world modeling.

    Special topic
  20. 16

    3D World Models I: 3D and 4D Representations

    Points, meshes, voxels, fields, radiance fields, Gaussian splats, persistent point identity, visibility, coordinate frames, and deformation.

    Slides (PDF)
    Lecture 15
  21. 17

    3D World Models II: Learning, Prediction, and Generation

    Learning geometry and tracking from images, action-conditioned 3D prediction, and native and video-based spatial generation.

    Lecture 16
  22. 18

    Neural Physics and Learned Physical Dynamics

    Learned simulators for particles, meshes, fluids, and deformable objects; graph networks, neural operators, physical priors, and long-horizon stability.

    Lecture 17
  23. 19

    World Models for Robot Learning I: Simulation, Control, and Sim-to-Real

    Classical and learned dynamics for model-based control, system identification, domain randomization, and sim-to-real transfer.

    Lecture 18
  24. 20

    World Models for Robot Learning II: Vision-Language-Action and World-Action Models

    Vision-language-action policies, latent actions, video pretraining, and world-action models that jointly predict futures and robot actions.

    Lecture 19
  25. 21

    LLM as World Models

    Language-model world representations, state tracking, executable simulations, reasoning, and feedback for digital agents.

    Lecture 20
  26. 22

    Evaluating World Models: Utility, Robustness, and Open Problems

    Utility, controllability, calibration, OOD behavior, intervention, drift, latency, and failure.

    Lecture 21
  27. 23

    Invited Lecture: Randall

    Guest lecture by Randall. Topic to be announced. Penn follows a Thursday schedule on Tuesday.

    Invited lecture
  28. —

    No class — Thanksgiving Break

    University break.

  29. 24

    Final Project Presentations

    Student project presentations, discussion, and course synthesis.

  30. 25

    Final Exam

    In-class final exam covering the core concepts developed throughout the course.

Lecture slides

Lecture 1World Models: An Overview

Resources

A growing collection of useful blogs, tutorials, seminars, and systems. New links will be added throughout the semester.

Updated throughout Fall 2026

Coursework

All assignment and project dates are collected here, separate from the lecture schedule. Specifications and grading weights are posted before each release.

01

Assignment 1

Out
Sep 10
Due
Sep 24
02

Assignment 2

Out
Sep 30
Due
Oct 19
03

Assignment 3

Out
Nov 2
Due
Nov 18

Final project

Final project data are now available. See Canvas for instructions and updates.

Explore a world-modeling method in one application domain, making the modeled state, transition, action interface, and evaluation criteria explicit.

Physical systemsVideo & spatial worldsRobot learningLanguage & digital agents
  1. Proposal

    Question, domain, method, and evaluation plan.

  2. Checkpoint

    Working system, early evidence, and risks.

  3. Final project presentations

    Results, failure analysis, and discussion.

  4. Report + code

    Final submission; exact format to be announced.

Logistics

Everything marked “to be announced” is confirmed and posted here before classes begin.

Office hours & course contact

Instructor office hours: Thursdays, 4:30–5:30 PM, AGH 423. Course questions and temporary meeting links are posted on Canvas.

Grading, late work & AI use

To be announced

Academic integrity

Penn’s Code of Academic Integrity applies to all work in this course.

Read the code ↗
Is this a reinforcement learning course?

No. We teach the RL and control machinery needed to understand how learned world models support decisions, but the course also covers representation learning, generative modeling, video and 3D, robotics, language, and digital agents.

Is the schedule final?

Class dates and major milestones are set. Topic order, readings, and guest speakers may still change, and per-session materials are linked from the schedule as they are ready.

What will the final project look like?

You explore a world-modeling method in one application domain. Final project data are now available. See Canvas for project instructions and updates.