Recent advances in diffusion models have significantly improved text-to-video generation, enabling personalized content creation with fine-grained control over both foreground and background elements. However, precise face-attribute alignment across subjects remains challenging, as existing methods lack explicit mechanisms to ensure intra-group consistency. Addressing this gap requires both explicit modeling strategies and face-attribute-aware data resources. We therefore propose LumosX, a framework that advances both data and model design. On the data side, a tailored collection pipeline orchestrates captions and visual cues from independent videos, while multimodal large language models (MLLMs) infer and assign subject-specific dependencies. These extracted relational priors impose a finer-grained structure that amplifies the expressive control of personalized video generation and enables the construction of a comprehensive benchmark. On the modeling side, Relational Self-Attention and Relational Cross-Attention intertwine position-aware embeddings with refined attention dynamics to inscribe explicit subject-attribute dependencies, enforcing disciplined intra-group cohesion and amplifying the separation between distinct subject clusters. Comprehensive evaluations on our benchmark demonstrate that LumosX achieves state-of-the-art performance in fine-grained, identity-consistent, and semantically aligned personalized multi-subject video generation. Code and models are available at https://jiazheng-xing.github.io/lumosx-home/.
Figures & tables
Figure 1: Lumos X supports flexible personalized multi-subject video generation.
Figure 2: Dataset construction pipeline for personalized multi-subject video generation. We build the training dataset from raw videos in three steps: (1) generate a caption and detect human subjects in extracted frames; (2) retrieve entity words from the caption and match subjects with their attributes; (3) use these entity tags to localize and segment target subjects and objects, producing a clean background image.
Figure 3: Overview of Lumos X . Built on the T2V model Wan2.1 [ 40 ] , our framework encodes all condition images into image tokens via a VAE encoder, concatenates them with denoising video tokens, and feeds the result into DiT [ 31 ] blocks. Within each block, the proposed Relational Self-Attention and Relational Cross-Attention enable causal conditional modeling, enhance visual token representations, and ensure precise face–attribute alignment.
Figure 4: Illustration of Attention Mask Design: Causal Self-Attention Mask (CSAM) and Multilevel Cross-Attention Mask (MCAM). We present a specific customized task case as an example.
Table 5
Methods
Entire Video
Extracted Subjects
Dynamic ↑
ViCLIP-T ↑
ViCLIP-V ↑
CLIP-T↑
CLIP-I ↑
DINO-I↑
ArcSim↑
CurSim↑
SkyReels-A2 [ 8 ]
0.671
0.251
0.839
0.178
0.606
0.192
0.271
0.290
Phantom [ 24 ]
0.661
0.254
0.865
0.185
0.647
0.216
0.444
0.477
Lumos X
0.723
0.260
0.932
0.201
0.692
0.261
0.454
0.483
Table 3: Comparison of different methods for subject-consistent video generation, including evaluation of the entire video and evaluation on the extracted subjects.
Figure 5: Qualitative comparison for identity-consistent and subject-consistent video generation.
Methods
CLIP-T↑
ArcSim ↑
None
0.184
0.316
+R2PE
0.178
0.363
+R2PE + CSAM
0.182
0.363
+R2PE + CSAM + MCAM ( 0.1 )
0.182
0.364
+R2PE + CSAM + MCAM ( 0.5 )
0.186
0.429
+R2PE + CSAM + MCAM ( 1.0 )
0.187
0.384
Table 4: Ablation study for the subject-consistent video generation. The value in the MACM parentheses is r .
Appendix figures & tables20 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 6: Process of entity words retrieval and subject-attributes matching with four steps: Data Collection, Data Organization, Data Processing, and Data Annotation.
Figure 7: Process of acquiring condition images of subjects, objects, and the background.
Methods
Numbers
Identity Consistency
Prompt Following
ArcSim ↑
CurSim ↑
ViCLIP-T ↑
SkyReels-A2 [ 8 ]
1 face
0.509
0.540
0.258
Phantom [ 24 ]
1 face
0.602
0.637
0.261
Lumos X
1 face
0.542
0.575
0.262
SkyReels-A2 [ 8 ]
≥ 2 faces
0.282
0.292
0.263
Phantom [ 24 ]
≥ 2 faces
0.434
0.457
0.266
Appendix
Table 5: Fine-grained quantitative comparison of identity-consistent video generation across different numbers of faces.
Methods
Numbers
Entire Video
Extracted Subjects
Dynamic ↑
ViCLIP-T ↑
ViCLIP-V ↑
CLIP-T↑
CLIP-I ↑
DINO-I↑
ArcSim↑
CurSim↑
SkyReels-A2
1 subject
0.772 (0.080)
0.252 (0.007)
0.870 (0.064)
0.177 (0.022)
0.604 (0.082)
0.199 (0.069)
0.356 (0.133)
0.380 (0.136)
Phantom
1 subject
0.848 (0.004)
0.254 (0.005)
0.880 (0.054)
0.186 (0.013)
0.646 (0.040)
0.215 (0.053)
0.539 (0.050)
0.581 (0.065)
Lumos X
1 subject
0.852
0.259
0.934
0.199
0.686
0.268
0.489
0.516
SkyReels-A2
2 subjects
0.655 (0.009)
0.251 (0.011)
0.820 (0.110)
0.182 (0.021)
0.620 (0.079)
0.185 (0.064)
0.216 (0.227)
0.233 (0.241)
Phantom
2 subjects
0.526 (0.138)
0.255 (0.007)
0.856 (0.074)
0.188 (0.015)
0.658 (0.041)
0.215 (0.034)
0.396 (0.047)
0.424 (0.050)
Appendix
Table 6: Fine-grained quantitative comparison of subject-consistent video generation across different numbers of subjects. ( ⋅ ) denotes that the respective method yields a lower value than our Lumos X on this metric, whereas ( ⋅ ) indicates better performance. Values in parentheses are recalibrated differences computed as (Method − Lumos X ) for the same setting and metric.
Methods
Entire Video
Extracted Subjects
Dynamic ↑
ViCLIP-T ↑
CLIP-T↑
CLIP-I ↑
DINO-I↑
ArcSim↑
CurSim↑
SkyReels-A2 [ 8 ]
0.839
0.235
0.207
0.614
0.173
0.160
0.166
Phantom [ 24 ]
0.929
0.255
0.226
0.623
0.195
0.271
0.305
Lumos X
0.804
0.247
0.232
0.668
0.336
0.317
0.346
Appendix
Table 7: Comparison of different methods for subject-consistent video generation, including evaluation of the entire video and evaluation on subjects.
Figure 8: Visualization of 10-person T2V results of our baseline model Wan2.1-T2V-1.3B.
Methods
Subject Consistency ↑
Background Consistency ↑
Motion Smoothness ↑
Face Consistency ↑
SkyReels-A2 [ 8 ]
0.654
0.798
0.979
0.739
Phantom [ 24 ]
0.768
0.853
0.986
0.883
Lumos X
0.962
0.946
0.988
0.895
Appendix
Table 8: Quantitative comparison of temporal coherence metrics on subject-consistent video generation.
Method
#Base Model
Text-S ↑
Vid-S ↑
Subj-S ↑
Dync-D ↑
SkyReels-A2 [ 8 ]
Wan2.1-14B-T2V
0.253
0.781
0.554
0.783
Phantom [ 24 ]
Wan2.1-1.3B-T2V
0.270
0.696
0.534
0.461
Lumos X
Wan2.1-1.3B-T2V
0.258
0.707
0.549
0.786
Appendix
Table 9: Quantitative comparison on MSRVTT-personalization [ 5 ] benchmark. boldfacen and underline font indicate the highest and the second highest results.
Figure 9: Visual effectiveness of individual components proposed in our Lumos X .
Figure 11: Qualitative comparison under varying control hyperparameters r in MCAM.
Method
FID ↓
AI Judgement ↑
Stable-Diffusion-2-Inpainting
96.32
36%
FLUX-Inpainting
92.83
64%
Appendix
Table 10: Comparison between Stable-Diffusion-2 [ 33 ] and FLUX [ 21 ] for background inpainting.
Figure 12: Qualitative comparison between Stable-Diffusion-2 and FLUX for background inpainting.
Figure 13: Human study results for multi-subject video customization. (a) Results across the four evaluation dimensions. (b) Average scores computed over all four dimensions.
Methods
Attribute Control
CLIP-T
CLIP-I
DINO-I
SkyReels-A2 [ 8 ]
text-only
0.192
0.643
0.192
text&visual
0.178
0.606
0.192
Phantom [ 24 ]
text-only
0.207
0.687
0.209
text&visual
0.185
0.647
0.216
Lumos X
text-only
0.205
0.684
0.210
text&visual
0.193
0.681
0.265
Appendix
Table 11: Quantitative comparison of text-only vs. text&visual attribute control across methods.
Methods
Entire Video
Extracted Subjects
Dynamic ↑
ViCLIP-T ↑
ViCLIP-V ↑
CLIP-T↑
CLIP-I ↑
DINO-I↑
ArcSim↑
CurSim↑
UNO + Wan2.1-I2V-14B
0.547
0.261
0.880
0.201
0.650
0.197
0.237
0.244
Lumos X
0.723
0.260
0.932
0.201
0.692
0.261
0.454
0.483
Appendix
Table 12: Comparison of image-personalization–based method and Lumos X for subject-consistent video generation, including evaluation of the entire video and evaluation on subjects.
Methods
Self-Attn Latency
Cross-Attn Latency
Latency/step
FLOPs/step
GPU Memory Usage
None
0.1440s
0.0026s
8.66s
195.44 T
21.5G
+R2PE
0.1441s
0.0025s
8.66s
195.44 T
21.5G
None (MagiAttention in Self-Attn)
0.0935s
0.0025s
5.79s
195.44 T
21.5G
+R2PE (MagiAttention in Self-Attn)
0.0936s
0.0026s
5.79s
195.44 T
21.5G
+R2PE+CSAM
0.0966s
0.0026s
5.81s
195.44 T
21.5G
+R2PE+CSAM+MCAM
0.0965s
0.0045s
6.11s
195.46 T
22.7G
Appendix
Table 13: Inference-stage computational overhead and latency statistics for each module under the same video customization case on an H20 GPU.
Figure 14: Qualitative comparison for identity-consistent video generation.
Figure 15: Qualitative comparison for subject-consistent video generation.
Figure 16: Qualitative comparison for subject-consistent video generation.