Real-world data as the foundation for robotics simulations

Four tasks from the ABC dataset, reconstructed from real-world trajectories.Unlocking a padlock, a task from the ABC dataset, reconstructed from a real-world trajectory. The real demonstration is on the left and the reconstructed simulation is on the right. Real footage from the ABC dataset; simulations by Versor.Explore all tasks ↓

Simulation is only useful if its lessons transfer to the real world. At Versor, we are building real-to-sim-to-real systems that use real-world interactions to bridge the sim-to-real gap, turning real-world experience into realistic environments.

Central to our tech is visual system identification, which tracks objects and their articulation throughout a real world episode, and infers the physical properties of the objects, robot, and scene using the recorded interaction. Through physics stress tests and replay of real-world actions, we ensure that the environments are ready for reinforcement learning, data generation, and sim-to-real policy training.

Today, we are releasing 1,000 simulation environments reconstructed from real-world demonstrations for five manipulation tasks in the ABC dataset (Allshire et al., 2026). Every environment is a unique combination of robot cell, objects in the scene and layouts reconstructed from real trajectories.

  1. 1Real trajectories

    Real-world interaction data

  2. 2Simulation environment

    Scene, objects and physics reconstructed to match the real interactions

  3. RL

    3Train policies

    Generate demonstrations, train and improve the policy with reinforcement learning

  4. realsimπ

    4Validate and deploy

    Validate and improve the learned policy in sim before real-world deployment

Grounded real-to-sim-to-real. Versor uses real-world interaction data to generate simulated scenes that match real-world physics. The simulation then provides training grounds for policies, through reinforcement learning and expert data generation. Trained policies can be evaluated and improved in this grounded simulation that reproduces real-world failures, before real-world deployment.

Simulation environments ready for robot learning

The release spans five manipulation tasks that represent some of today's main challenges in robot learning: fine-grained manipulation (sorting screws and nuts), bimanual coordination (loading plates into a dish rack), deformable objects (placing snacks into a paper bag), and reorienting and placing objects (flipping mugs, placing bottles in a bin). Each environment was automatically reconstructed from a real-world demonstration to reproduce its scene, objects, and interactions.

Explore different layouts for each task. Hover over a real or simulated frame to magnify the same region in both.

Flip mugs upright

Flip mugs upright, real sceneReal
Flip mugs upright, scene rebuilt from that frameSim
Flip mugs upright, real sceneReal
Flip mugs upright, scene rebuilt from that frameSim

Sort screws and nuts

Sort screws and nuts, real head cameraReal
Sort screws and nuts, scene rebuilt from that frameSim
Sort screws and nuts, real head cameraReal
Sort screws and nuts, scene rebuilt from that frameSim

Place snacks into a paper bag

Place snacks into a paper bag, real head cameraReal
Place snacks into a paper bag, scene rebuilt from that frameSim
Place snacks into a paper bag, real head cameraReal
Place snacks into a paper bag, scene rebuilt from that frameSim

Three of the five tasks we release. Each pair is a frame from a real demonstration beside its reconstructed environment. Real images from the ABC dataset; reconstructed simulations by Versor.

Reconstruction lets us match the distribution of scenes that a policy encounters in the real world. Other simulation datasets sample object layouts that are significantly simpler than real-world, while our episode-centric reconstructions preserve the clutter the robot actually encounters.

Real screw-sorting scene from the ABC datasetReal
Versor reconstruction of the same screw-sorting sceneVersor
ABC default screw-and-nut simulation sceneABC
Versor reconstructed simulation against ABC's default simulation. Our environments match the layout complexity that robots encounter in the real world. Real image: ABC.

Beyond the five released tasks, we have also reconstructed tasks such as folding a paper box, opening a wallet, placing AirPods in their case, and unlocking a padlock, covering deformation, articulation, and precise contact. The explorer below shows 10 tasks, three from the release and seven beyond it: pick one to watch the real demonstration beside its reconstruction.

Explore the tasks

    REALSIM

    Ten reconstructed tasks spanning rigid, deformable and articulated objects, transparent glassware, and fine-grained contact. Each shows the real demonstration (ABC) on the left and its reconstruction on the right.

    Sim-to-real policy evaluation

    Simulation lets us compare checkpoints and inspect behaviors before running a policy on a physical robot, provided that performance in simulation reflects performance in the real world. We evaluate ABC’s released checkpoints in simulated reconstructions of its real-world evaluation scenes for mug flipping, bottle placement, and dishrack loading, and compare their task progress with the real robot’s.

    Simulation ranks the checkpoints almost exactly as the real robot does, matching 15 of the 18 pairwise orderings. Across the four checkpoints, simulated and real task progress are strongly correlated, with Pearson correlations of 0.996 for bottle placement, 0.92 for mug flipping and 0.71 for dishrack loading.

    sim = real 0255075100Real task progress, % 0255075100Sim task progress, % DiT-200kVLA-200kVLA-100kVLA-50kDiT-200kVLA-200kVLA-50kDiT-200kVLA-100kVLA-50k Mug flipr = +0.92 · 50 twins eachBottlesr = +0.996 · 50 twins eachLoad dishrackr = +0.71 · 50 twins eachBars ±1 SE on both axes. Each r isover four checkpoints in one series.Hover a point for its numbers;click a series to hide it.
    Mean task progress in sim and real for the four ABC checkpoints. Error bars show ±1 standard error of the mean, and correlations are computed across the four checkpoint means. Simulation ranks the checkpoints in nearly the same order as the real robot.
    See more details on the checkpoint evaluations

    How we evaluated checkpoints

    For each task and checkpoint we took 50 episodes from ABC's released real-world evaluation set. We rebuilt the scene of each episode in simulation and ran the same checkpoint in that reconstruction, so every simulated rollout has a real counterpart with the same layout and the same policy. Task progress is scored with ABC's evaluation protocol, and we report the mean and standard deviation across episodes.

    Results by task

    The charts below break the results down by task. Each pair of bars is one checkpoint, the real robot on the left and simulation on the right. Bottle placement agrees closely in level, mug flipping scores higher in simulation but keeps the real ordering, and dishrack loading swaps its two middle checkpoints.

    Mug flipping
    0255075100Task progress (%)DiT-200kVLA-200kVLA-100kVLA-50k41.052.334.044.025.542.725.042.0
    Bottle placement
    0255075100DiT-200kVLA-200kVLA-100kVLA-50k93.396.792.395.794.095.774.778.3
    Dishrack loading
    0255075100DiT-200kVLA-200kVLA-100kVLA-50k80.575.571.668.876.063.770.363.0

    Mean task progress per checkpoint, real against simulation, with each mean printed on its bar. Whiskers show ±1 SD across episodes, cut at 0 and 100%.

    Agreement between simulation and the real robot

    We use four metrics to compare performance in simulation and on the real robot, shown in the table below. Pairwise orderings counts how many of the six pairs of checkpoints come out in the same order in both. Pearson r shows how well the simulated scores move with the real ones. MMRV, from SIMPLER (Li et al., 2024), is 0 when the order is fully preserved and grows when simulation swaps checkpoints that are far apart on the real robot. The mean absolute gap is how many points simulation is off, on average.

    Mug flipping keeps every ordering, though simulation scores it about 14 points higher than the real robot. Bottle placement is the closest absolute match, about 3 points off; simulation swaps two checkpoints only 0.7 points apart on the real robot, and ties two others (95.7 each) that are 1.7 points apart on the real robot. We count a tie as a miss in ordering. For dishrack, simulation swaps two checkpoints which are 4.4 points apart on the real robot. Note that with 50 episodes per checkpoint, differences of a few points can be noise, and all simulation means are within 1 standard deviation of their real counterparts.

    Task Pairwise orderings ↑ Pearson r ↑ MMRV ↓ Mean absolute gap (pp) ↓
    Mug flipping 6/6 0.92 0.000 13.9
    Bottle placement 4/6 0.996 0.003 3.0
    Dishrack loading 5/6 0.71 0.022 6.9

    Mug flipping scores

    Checkpoint Real mean ± SD (%) Sim mean ± SD (%)
    DiT-200k 41.0 ± 21.1 52.3 ± 27.8
    VLA-200k 34.0 ± 25.9 44.0 ± 26.2
    VLA-100k 25.5 ± 21.5 42.7 ± 22.4
    VLA-50k 25.0 ± 21.2 42.0 ± 26.2

    Bottle placement scores

    Checkpoint Real mean ± SD (%) Sim mean ± SD (%)
    DiT-200k 93.3 ± 14.1 96.7 ± 8.8
    VLA-200k 92.3 ± 12.6 95.7 ± 8.0
    VLA-100k 94.0 ± 17.2 95.7 ± 11.5
    VLA-50k 74.7 ± 31.8 78.3 ± 27.0

    Dishrack loading scores

    Checkpoint Real mean ± SD (%) Sim mean ± SD (%)
    DiT-200k 80.5 ± 16.6 75.5 ± 21.7
    VLA-200k 71.6 ± 25.5 68.8 ± 20.8
    VLA-100k 76.0 ± 17.0 63.7 ± 23.5
    VLA-50k 70.3 ± 18.9 63.0 ± 23.4

    Simulation reproduces real-world failures

    Aggregate metrics help select checkpoints for deployment but policy behavior can reveal policy weaknesses, helping target new training data. Typically, while sim and real might agree in aggregates, exact behaviors do not match due to distribution shifts. With our reconstructed scenes, we observe a strong sim and real behavior correspondence, beyond aggregate metrics.

    Below are three examples where we observe the same failure mode in sim and real: a mug dropped during handover, a plate slipping during pick, and a bottle missing the bin. These shared behaviors show how simulation can help identify potential failures and guide data generation and retraining for more reliable policies.

    REALSIM

      Simulated and real episodes of the same checkpoint fail in similar ways. The failures play one after another; select one below the video to jump to it. Real footage from the ABC dataset; simulations by Versor.

      Sim-to-real transfer in a new robot cell

      Beyond evaluating policies, our environments can generate the data to train them. Adapting a policy to a new robot cell usually requires collecting teleoperated demonstrations in that target cell, which can be time consuming and slows down deployments. Instead, we reconstruct a new YAM cell in simulation and fine-tune an open-source VLA only on data generated in that simulation, without collecting any real-world demonstrations in the new cell.

      We test this on the mug flipping task, included in this release. The robot picks up mugs from a tray, hands them over to the other arm, flips, and places them. We start from VLA-200k, a checkpoint ABC trained on its real-world data, and compare two ways to fine-tune it: using ABC's real-world mug-flipping episodes, or using demonstrations generated in our simulation of the new cell. Neither dataset includes real-world data from the new cell. First, we show how the policies performed on the real robot; then we explain how we generated the simulation data.

      Real-robot results

      We evaluate each policy in the real cell across six layouts, and four trials per layout. Each evaluation has two mugs, and task progress scores an episode 0%, 50% or 100% for zero, one or two mugs left upright. Strict success 1.0 when both mugs are placed upright, and 0.0 otherwise. Without fine-tuning, VLA-200k makes little progress on the new cell. Fine-tuning on ABC's real-world data reaches 35% mean task progress and 8% strict success. Fine-tuning on Versor's simulation data reaches 60% task progress and 33% strict success (closely matching simulation performance of 59.7% task progress and 27% strict success).

      None of these policies saw real-world demonstrations from the new cell, but the policy fine-tuned in simulation still achieved 33% strict success. There is still a lot of room for improvement, but this is an early signal on how simulation can supply cell-specific training data without collecting new teleoperated demonstrations.

      Real-world evaluation of the policy finetuned on sim data

      Sample real-world evaluations of the policy trained on simulation data.
      Mean task progress
      0255075100Task progress (%)Base policy8%Real only35%Sim results60%
      Full successes
      0255075100Episodes completed (%)Base policy4%Real only8%Sim results33%

      We measure mean task progress and the share of episodes that complete the full task, on the real robot. Whiskers show ±1 standard error and 95% Wilson intervals.

      Fine-tuning VLA-200k for the new cell: real-robot episodes per policy
      Fine-tuning dataMean task progress (%)Full successes
      Base policy8 ± 54% (95% interval 1–20%)
      Real only35 ± 68% (95% interval 2–26%)
      Sim results60 ± 733% (95% interval 18–53%)

      Generating the simulation data

      The strongest results came from training on simulated data of the new cell. To generate this data, we combine motion retargeting, which adapts real-world demonstrations recorded in other cells to the new cell, with reinforcement learning, where policies practice the task in simulation and learn from their attempts. Together, these methods produce perfect demonstrations, new strategies, as well as, failures and recoveries, such as setting a toppled mug upright or retrying after a missed grasp. In total, we generate 3,252 episodes, about 18 hours of robot data. Each episode has two mugs in randomized positions, with randomized lighting, camera pose, and wall and table tint.

      SIM · lifts a fallen mug
      SIM · pick and handover
      SIM · distant mug
      SIM · pulls the tray closer
      SIM · flips both mugs
      SIM · flips both mugs
      SIM · mug on its side
      SIM · missed grasp
      Simulated episodes in the new cell, each in its own layout and rendered under different lighting conditions. Top: episodes that start with a mug on its side, hand a mug over, reach for a distant mug, or pull the tray closer first. Bottom: episodes that flip both mugs and recover from failures, such as a mug on its side or a missed grasp.

      What's next

      Building our simulations from real-world data allows us to precisely capture the robot and scene properties that matter in the real world. That realism lets us train and evaluate policies, from demonstrations or reinforcement learning, and transfer to the real world. Next, as we get more real world evaluation data, we are feeding this back to the simulator, and training more reliable and performant policies, continuously improving the real-to-sim-to-real loop.

      In addition, we are extending our environments to longer, contact-rich commercially valuable tasks, and to a wide range of objects and materials. To learn more about our work and help push real-to-sim-to-real forward, get in touch at founders@versor.tech.

      Citation

      If you use these scenes, please cite our post and the ABC paper:

      BibTeX
      @misc{versor2026abcsim,  title        = {Real-world data as the foundation for robotics simulations},  author       = {{Versor}},  year         = {2026},  howpublished = {\url{https://versor.tech/news/abc-sim/}}}@article{allshire2026abc,  title   = {Scalable Behavior Cloning with Open Data, Training, and Evaluation},  author  = {Arthur Allshire and Himanshu Gaurav Singh and Ritvik Singh and Adam Rashid and Hongsuk Choi and David McAllister and Justin Yu and Yiyuan Chen and Huang Huang and Pieter Abbeel and Xi Chen and Rocky Duan and Phillip Isola and Jitendra Malik and Fred Shentu and Guanya Shi and Philipp Wu and Angjoo Kanazawa},  journal = {arXiv preprint arXiv:2606.27375},}
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