SlotDiT: Object-Centric Representations for Diffusion Transformers

British Machine Vision Conference (BMVC) 2026

Abstract

Text-conditioned latent diffusion models are powerful video generators and promising backbones for robotic applications, but common pixel- or VAE-based latents prioritize reconstruction fidelity and lack explicit semantic structure. Object-centric slots instead decompose a scene into compact representations of its entities.

We introduce SlotDiT, a text-guided Diffusion Transformer operating in a slot-based latent space. Given one reference image, it extracts object-centric slots and, conditioned on the text instruction and scene context, autoregressively denoises future slot trajectories, enabling the prediction of future scene dynamics.

We compare slot, VAE-based, and semantics-aligned latents within one unified DiT setup across four robotic datasets. SlotDiT delivers competitive visual quality, consistently stronger task completion, leading robot-control performance, and substantially faster inference.

Method

SlotDiT

Given a reference image and language instruction, SlotDiT first encodes the scene into a compact set of object-centric slots. Conditioned on the instruction and observed slots, the diffusion transformer iteratively denoises future slot trajectories from Gaussian noise.

The latest predicted slots are reused as context for autoregressive generation, and a frozen object-centric decoder can render the resulting trajectories as future frames.

SlotDiT pipeline from a reference image and language instruction to future object-centric slots and decoded frames
Figure 1(a). SlotDiT parses the reference image into slots and autoregressively denoises future slot trajectories conditioned on language and scene context.
Experiments

Evaluation

We isolate the effect of the latent space by comparing object-centric slots with VAE-based and semantics-aligned representations under the same DiT architecture, training procedure, and inference scheme.

Evaluation comprises two distinct tasks: text-guided video generation on CLIPort, LanguageTable-Synthetic, LanguageTable-Real, and BridgeData V2; and robot control on CLIPort and LanguageTable-Synthetic.

VAE-based, semantics-aligned, and object-centric slot latent representations
Figure 1(b). Latent spaces compared in the unified DiT study.
Evaluation task 01

Text-Guided Video Generation

SlotDiT outperforms all the VAE-based baselines by achieving the highest task-success rate on CLIPort (87.8%), LanguageTable-Synthetic (79.7%), and LanguageTable-Real (64.6%), while remaining competitive on BridgeData V2 (57.6%). VAE-based baselines can obtain stronger perceptual scores, but visual fidelity alone does not reliably indicate instruction following or task completion.

Text-guided video generation results on four robotic datasets
Text-guided video generation results at prediction horizon of 29 future frames. Click to view full size.

Qualitative comparison

These rollouts illustrate the metric–task gap: visually plausible baselines may preserve appearance yet fail to execute the instruction, while SlotDiT models the task-relevant object dynamics and its predictions correctly illustrate the completed task.

Evaluation task 02

Robot Control

For the robot control setting, we use inverse dynamics models (IDMs) to map predicted latents to actions. SlotDiT reaches 73.0% success in open-loop robot control on CLIPort and 74.5% in the in-distribution closed-loop LanguageTable-Synthetic setting, leading all learned predictors and nearly matching the GT slots oracle.

It remains strongest in the LanguageTable-Synthetic's out-of-distribution scenarios—harder eight-block scenes and unseen instruction templates—showing that object-centric dynamics retain task-relevant information beyond training.

Robot-control success on CLIPort and LanguageTable-Synthetic robustness settings
Robot-control success. SlotDiT leads the learned predictors and is close to the ground-truth-slot oracle in distribution. Click to view full size.
Model analysis

Efficiency

Average task success versus inference throughput for SlotDiT and latent-space baselines
Figure 1(c). SlotDiT combines the highest average task completion with the fastest inference.

SlotDiT represents each frame with only 10 slot tokens, compared with 256 tokens for the alternative latents. It reaches 9.33 FPS, a 5.68× speedup over DiT + SD-VAE, with most of the gain coming from diffusion sampling, highlighting the efficiency gains from the compact and semantic object-centric latent space.

Inference time, throughput, and token-count comparison
Inference efficiency on CLIPort. Compact slot trajectories substantially reduce diffusion sampling cost. Click to view full size.
Model analysis

Controllability

Given the same initial observation, SlotDiT generates distinct future trajectories for two different instructions, while preserving the overall scene layout and object identities. In both cases, SlotDiT is able to identify the new objects and correctly applies the described motion, seamlessly adapting to the new text instruction.

CLIPort

Instructionput the yellow block in the blue bowl

Changedput the red block in the blue bowl

Ground truth
Ground truth
Original instruction
Original instruction
Changed instruction
Changed instruction

LanguageTable-Synthetic

Instructionmove the star to the blue cube

Changedmove the pentagon to the blue cube

Ground truth
Ground truth
Original instruction
Original instruction
Changed instruction
Changed instruction

LanguageTable-Real

Instructionslide the green star on top of yellow hexagon

Changedslide the red circle on top of yellow hexagon

Ground truth
Ground truth
Original instruction
Original instruction
Changed instruction
Changed instruction

BridgeData V2 - Example 1

Instructionmove the pot to the cooker

Changedmove the yellow object to the cooker

Ground truth
Ground truth
Original instruction
Original instruction
Changed instruction
Changed instruction

BridgeData V2 - Example 2

Instructionmove the corn to the stove

Changedmove the lit to the stove

Ground truth
Ground truth
Original instruction
Original instruction
Changed instruction
Changed instruction
Inside the representation

Object-Centric Behaviour

SlotDiT models scene dynamics through persistent object-level representations. The masks show the decomposition of each predicted frame, while the individual slot reconstructions reveal how individual scene entities are represented and how they evolve over time.

BridgeData V2 · Example 1

Instruction-conditioned object-centric rollout

Ground truth
Ground truth
SlotDiT prediction
SlotDiT prediction
Slot masks
Slot masks
Object 1
Object 1
Object 2
Object 2
Object 3
Object 3
Object 4
Object 4

BridgeData V2 · Example 2

Instruction-conditioned object-centric rollout

Ground truth
Ground truth
SlotDiT prediction
SlotDiT prediction
Slot masks
Slot masks
Object 1
Object 1
Object 2
Object 2
Object 3
Object 3
Object 4
Object 4
Conclusion

Key Findings

  • Object-centric DiT latents improve instruction following and task completion while retaining competitive visual quality.
  • Perceptual video metrics alone do not measure whether a robotic instruction was actually completed successfully.
  • Compact object-centric slots make diffusion inference substantially more efficient than dense alternatives.
  • Object-centric structure proves to be a powerful inductive bias for diffusion-based generative modeling in robotic environments.
Citation
@inproceedings{plepi2026slotdit,
  title     = {SlotDiT: Object-Centric Representations for Diffusion Transformers},
  author    = {Plepi, Gjergj and Behnke, Sven},
  booktitle = {British Machine Vision Conference (BMVC)},
  year      = {2026}
}