Beyond One-Step Accuracy: State-Affine Latent Transition for Reliable Visual Planning
Authors: Boyuan Zhang, Yingjun Du, Xiantong Zhen, Ling Shao
Organizations: UCAS-Terminus AI Lab, School of Engineering Science, University of Chinese Academy of Sciences · VIS Lab, University of Amsterdam · Central Research Institute, United Imaging Healthcare, Co., Ltd.
Joint-embedding world models enable visual planning by learning action-conditioned dynamics in latent space. Yet they are commonly trained for one-step prediction on encoded states, while planning recursively applies the learned transition to its own predictions. One-step accuracy therefore does not capture how prediction errors propagate under recursive rollout. We decompose multi-step rollout error into the errors introduced at individual steps and their propagation through subsequent transitions. We show that state-affine dynamics are precisely the differentiable transitions with state-independent Jacobians, eliminating the nonlinear propagation residual and making the error propagation operators depend only on the action sequence. Guided by this result, we introduce SALT (State-Affine Latent Transition), an action-conditioned state-affine dynamics model in which the action modulates both the state transformation and the additive update. We train SALT through recursive multi-step rollout supervision, feeding each predicted latent state back into the transition so that training matches how the model is used during planning. Across four visual planning environments, SALT exhibits 1.48--2.19× higher one-step prediction error than the matched LeWM baseline, yet improves closed-loop success in every environment by 10.0 percentage points on average. On OGBench-Cube, the fraction of episodes that fail with a sharp rise in model-predicted cost after execution decreases from 23.3 to 2.0.
Figures & tables
Figure 1 : State dependence and current-state rollout reconstruction of the LeWM predictor. (a) Distribution of σmax(∂zF) for the current-state Jacobian across 12 fixed action sequences while varying the current latent state. Points denote samples, the thick bar shows the interquartile range, and the dashed line marks σmax=1 . (b) Relative discrepancy between the rollout error and its current-state first-order reconstruction as the rollout horizon increases. The reconstruction uses only current-state Jacobians and omits propagation through earlier history inputs.
Method
Two-Room
Reacher
PushT
OGBench-Cube
Avg.
PLDM †
97
78
78
65
79.50
DINO-WM †
100
79
74
86
84.75
Sub-JEPA †
95.00
84.00
89.00
76.33
86.08
SD-JEPA †
90.00
88.00
97.30
72.00
86.83
SMWM †
99.00
66.00
83.00
84.00
83.00
Random
2.00 ± 2.00
12.00 ± 4.00
5.30 ± 2.30
42.00 ± 4.00
15.33
Table 1: Closed-loop planning success rates (%) across four environments. Controlled evaluations use H=5 and report the mean ± standard deviation over three evaluation seeds of 50 episodes each. † quoted from the literature under different protocols. Bold marks the best mean among controlled rows.
Training (it/s)
Predictor
Params
Forward (ms)
One-step
Rollout
Planning (s)
LeWM (ViT-S)
11.58M
2.36
6.5
2.9
35.2
SALT (Affine)
0.70M ( × 16.5)
0.29 ( × 8.1)
6.0
2.4
11.4 ( × 3.1)
Table 2: Predictor complexity and computational efficiency. Parameter counts and single-step forward times cover the predictor together with its projection head. Planning time is the CEM wall-clock time averaged over the four environments and H∈{5,10,15,20} . Additional timing details are provided in Appendix B.6 .
Figure 2 : From one-step accuracy to recursive error propagation. (a) Relative one-step prediction error and closed-loop success across four environments. (b) Recursive rollout error on PushT. (c) Spectral norm of the measured propagation operator on PushT; the band spans the minimum and maximum over nine measurements.
Objective
LeWM
SALT
One-step
82.7
84.4
Rollout
77.8
92.7
Δ
-4.9
+8.3
Table 3: Transition structure and training objective. Mean closed-loop success rate (%) over Two-Room, Reacher, PushT, and OGBench-Cube, with equal weight assigned to each environment. Training windows, target frames, and training budgets are matched across objectives.
Figure 3 : Failure anatomy on OGBench-Cube. Among failed episodes, mismatch failures satisfy r=c/c^>5 , while unflagged failures satisfy r≤5 . Here, c^ and c are model-predicted terminal costs before execution and during subsequent replanning, respectively. The examples are reproduced LeWM failures, and all images are real observations. Bars report counts over 150 paired episodes per model.
Figure 4 : Long-horizon planning performance. Success rate on the four environments at H∈{10,15,20} . Arrows mark the performance difference between SALT and LeWM at H=10 and H=20 .
Method
Success rate
Random
32.7 ± 4.2
LeWM
36.0 ± 5.3
SALT
54.0 ± 3.5
Table 4: Success rate (%) on Cube-Double.
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
Component
Symbol
Shape
Parameters
Initialization
Generator of U
Wu
192×192
36,864
0
Generator of V
Wv
192×192
36,864
0
Singular-value parameters
s
192
192
3.0
Gate
Wg
16×192
3,072
U(−1/192,1/192)
Modulation modes
N1,…,N16
16×192×192
589,824
0
Action injection
B
192×192
36,864
0
Appendix
Table 5 : Parameters of the SALT transition model ( d=192 , R=16 ). Counts are stored parameters. Only the skew-symmetric parts of Wu and Wv affect the transition, corresponding to 18,336 independent entries for each matrix.
Figure 5 : Decoded open-loop rollouts across four environments. The first three columns ( t=0,5,10 ) are ground-truth context frames from the common evaluation interface. Only the final frame initializes SALT , which predicts seven subsequent latent states using dataset actions. At frameskip 5 , these predictions cover 35 additional environment steps ( t=15,…,45 ). Images are produced by a post-hoc decoder trained only on ground-truth latents and excluded from world-model training and planning.
Figure 6 : Rollout error and propagation across four environments. Top: relative rollout error as a function of rollout step k . Bottom: the spectral norm of the measured propagation operator Φ0→k . Results use test seeds 1 , 2 , and 3 . Blue circles denote reproduced LeWM; orange squares denote SALT . Each model step corresponds to five environment steps.
Model
Mismatch
Unflagged
LeWM
35/150 ( 23.3% )
17/150 ( 11.3% )
SALT
3/150 ( 2.0% )
6/150 ( 4.0% )
Appendix
Table 6 : Episode-level failure rates by type on OGBench-Cube. Rates are computed over 150 paired episodes per model using the fixed threshold r=5 . LeWM denotes the reproduced baseline.
Environment
Horizon
LeWM
SALT
Gap (pp)
Two-Room
10
63
74
+11
15
54
65
+11
20
47
58
+11
Reacher
10
26
30
+4
15
20
26
+6
20
18
26
+8
Appendix
Table 7 : Success rate (%) under the long-horizon protocol. Results correspond to the long-horizon experiment reported in the main text.
Configuration
Planning success
Action-independent transition matrix
11.3±3.1
Full structure
90.7±3.1
Appendix
Table 8 : Effect of removing the action-dependent modulation of the transition matrix. Success rate (%) on Reacher over three evaluation seeds.
Figure 7 : Success rate against the SIGReg weight on PushT. Shading shows standard deviation across three evaluation seeds; the dashed line marks the default λ=0.09 .
Figure 8 : Success rate of SALT against latent dimension on Two-Room and OGBench-Cube. The horizontal axis uses a base-two log scale; error bars show standard deviation across three evaluation seeds.
School of Computer Science and Technology, University of Chinese Academy of Sciences, Beijing · Institute of Information Engineering, Chinese Academy of Sciences, Beijing · School of Computer Science and Technology, Harbin Institute of Technology, Weihai +2