Unified Vision-Language Models (UVLMs) aim to advance multimodal learning by supporting both understanding and generation within a single framework. However, existing approaches largely focus on architectural unification while overlooking the need for explicit interaction between the two capabilities during task solving. As a result, current models treat understanding and generation as parallel skills rather than synergistic processes. To achieve real synergy, we introduce the interleaved Analyzing-Drafting problem-solving loop (AD-Loop), a new think paradigm that dynamically alternates between analytic and drafting operations. By interleaving textual thoughts with visual thoughts, AD-Loop enables models to iteratively refine both comprehension and outputs, fostering genuine synergy. To train this mechanism, we design a two-stage strategy: supervised learning on interleaved thought data to initialize alternation, followed by reinforcement learning to promote adaptive and autonomous control. Extensive experiments demonstrate that AD-Loop consistently improves performance across standard benchmarks for both understanding and generation, with strong transferability to various UVLMs architectures. Visual analyses further validate the effectiveness of implicit visual thoughts. These results highlight AD-Loop as a principled and broadly applicable strategy for synergizing comprehension and creation. The project page is at https://sqwu.top/AD-Loop.
Figures & tables
Figure 1: Illustration of the interleaved analytic–drafting problem-solving loop, where understanding and generation interact synergistically to yield accurate solutions.
Figure 2: Pipeline of our training framework. Stage-1 : train the UVLM to emit interleaved thinking traces. Stage-2 : apply GRPO for hybrid reasoning. The policy samples multiple traces with/without the interleaved AD-Loop for each input. A reward model scores outcomes, and then group-normalized advantages are applied to update the policy, teaching the model when AD-Loop helps.
Model
#Params
POPE ↑
MME-P ↑
MMB ↑
SEED ↑
GQA ↑
MMMU ↑
MM-Vet ↑
∙ Und. Only
LLaVA-v1.5 ( Liu et al., 2024a )
7B
85.9
1510.7
64.3
58.6
62.0
35.4
31.1
Qwen-VL-Chat ( Bai et al., 2023 )
7B
-
1487.5
60.6
58.2
57.5
–
–
IDEFICS ( Laurençon et al., 2023 )
8B
-
-
48.2
-
38.4
-
-
InstructBLIP ( Dai et al., 2023 )
13B
78.9
1212.8
-
-
49.5
–
25.6
∙ Und. and Gen.
Table 1: Comparison with baselines on multimodal understanding benchmarks. “Und.” and “Gen.” denote understanding and generation , respectively.
Model
Single Obj. ↑
Two Obj. ↑
Counting ↑
Colors ↑
Position ↑
Attri. ↑
Overall ↑
∙ Gen. Only
Emu3-Gen ( Wang et al., 2024 )
0.98
0.71
0.34
0.81
0.17
0.21
0.54
SDXL ( Podell et al., 2023 )
0.98
0.74
0.39
0.85
0.15
0.23
0.55
FLUX.1-dev ( Yang et al., 2024 )
0.99
0.81
0.79
0.74
0.20
0.47
0.67
SD3-Medium ( AI, 2025 )
0.99
0.94
0.72
0.89
0.33
0.60
0.74
∙ Und. and Gen.
Table 2: Comprehensive generation comparison on GenEval ( Ghosh et al., 2023 ) benchmark. “Und.” and “Gen.” denote understanding and generation , respectively.
Think Strategy
Understanding
Generation (WISE)
MathVista ↑
LogicVista ↑
SAT ↑
Cultural ↑
Space ↑
Biology ↑
Isolated thinking
61.5
40.2
0.63
0.44
0.68
0.44
T
68.3
44.1
0.74
0.67
0.69
0.56
T+I ( explicit )
72.9
46.6
0.81
0.73
0.74
0.64
T+I ( implicit )
73.6
47.2
0.84
0.75
0.77
0.65
T / T+I
75.8
49.5
0.89
0.79
0.78
0.68
Table 3: Comparison with different thinking strategies. Isolated thinking : understanding or generation performed in isolation; T : analyzing-only thinking; T+I (explicit) : supervised textual–visual (explicit) interleaving; T+I (implicit) : learned textual–visual (implicit) interleaving; T / T+I : adaptive interleaved thinking that automatically selects with or without interleaved thinking.
Figure 3: Qualitative comparison: original prompt (left), self-think mode, interleaved thoughts, and text-only thoughts filtered from the interleaved thoughts (right). [ V-T ] means latent visual thoughts.
Figure 4: Absolute performance gain after applying AD-Loop, comparing Janus-Pro with discrete tokenization and BAGEL with continuous embedding for visual thoughts learning.
MMstar
MathVista
LogicVista
GenEval
WISE (cultural)
WISE (Biology)
From Gen. Encoder
54.9
75.8
47.5
0.86
0.79
0.68
From Und. Encoder
51.6
70.9
44.3
0.84
0.71
0.61
Table 4: Comparison of latent visual representations learn by the generation (Gen.) vs. understanding (Und.) encoder.
Figure 5: Examples of latent visual thoughts. Each case shows the original image (left) and the corresponding visual thoughts (right), capturing abstract visual structures.
Figure 6: Performance across skills and capabilities on the LogicVista dataset, comparing models with and without visual thoughts, alongside the proportion of visual-thought usage.
Figure 7: Comparison of unified MLLMs on T2I generation. Existing models often fail on prompts requiring deeper reasoning, whereas our approach yields more faithful outcomes.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 8: Comparison of existing mechanisms for synergizing understanding and generation, including isolated learning where the two abilities are trained independently, dual learning which leverages cross-modal reconstruction for mutual supervision, and co-learning which jointly optimizes both tasks with paired samples.
Figure 9: Visualization of the constructed dataset. Given a user query, we establish an analyzing–drafting problem-solving loop in which textual and visual thoughts alternate dynamically, ultimately yielding the final answer.
Task
Dataset
Avg.
Stage-1
Stage-2
Total
Understanding
CMoT ( Cheng et al., 2025b )
3
1K
1K
2K
Visual-CoT ( Shao et al., 2024 )
2
12K
1K
13K
CoF ( Zhang et al., 2025b )
3
4K
1K
5K
VSP ( Yang et al., 2025b )
3
3K
1K
4K
Generation
GoT-T2I ( Fang et al., 2025 )
4
12K
3K
15K
Inter-T2I
4
10K
2K
12K
Appendix
Table 5: The statistics of the constructed dataset for two-stage learning. ‘Avg.’ indicates the average number of latent visual thoughts within the datasets.
Type
Model
Level 3
Level 6
Explicit
Anole ( Chern et al., 2025 )
0.02
0.00
MVoT ( Li et al., 2025 )
0.21
0.03
Implicit
Mirage ( Yang et al., 2025b )
0.75
0.39
Ours
0.81
0.47
Appendix
Table 6: Performance comparison of explicit and latent visual thoughts on the spatial visual planning task at levels 3 and 6.
Figure 10: Qualitative comparison across baseline unified MLLMs on multimodal understanding. Correct answers are marked in green , errors in red , and [ V-T ] denotes latent visual thoughts.
Figure 11: Understanding Comparison across UVLMs on the math question answering task. Correct answers are marked in green , errors in red , and [ V-T ] denotes latent visual thoughts.
Figure 12: Understanding Comparison across UVLMs on multimodal content reasoning task. Correct answers are marked in green , errors in red , and [ V-T ] denotes latent visual thoughts.
Figure 13: Generation Comparison across UVLMs.
Figure 14: Generation Comparison on MindOmni ( Xiao et al., 2025b ) and BAGEL ( Deng et al., 2025 ) with/without Think process.Our proposed method achieves more accurate generation results.
Figure 15: Editing Comparison on BAGEL ( Deng et al., 2025 ) with/without think process.
Figure 16: Failure cases illustrating over-drafting on simple tasks, as well as challenges on problems that require strictly logical mathematical reasoning.
Figure 17: Failure cases showing that the proposed method still struggles with rendering scene text, as well as fine-grained body details and numerically precise content.