Despite recent progress, video diffusion models still struggle to synthesize realistic videos involving highly dynamic motions or requiring fine-grained motion controllability. A central limitation lies in the scarcity of such examples in commonly used training datasets. To address this, we introduce DynaVid, a video synthesis framework that leverages synthetic motion data in training, which is represented as optical flow and rendered using computer graphics pipelines. This approach offers two key advantages. First, synthetic motion offers diverse motion patterns and precise control signals that are difficult to obtain from real data. Second, unlike rendered videos with artificial appearances, rendered optical flow encodes only motion and is decoupled from appearance, thereby preventing models from reproducing the unnatural look of synthetic videos. Building on this idea, DynaVid adopts a two-stage generation framework: a motion generator first synthesizes motion, and then a motion-guided video generator produces video frames conditioned on that motion. This decoupled formulation enables the model to learn dynamic motion patterns from synthetic data while preserving visual realism from real-world videos. We validate our framework on two challenging scenarios, vigorous human motion generation and extreme camera motion control, where existing datasets are particularly limited. Extensive experiments demonstrate that DynaVid improves the realism and controllability in dynamic motion generation and camera motion control.
Figures & tables
Figure 2: Overview of our dataset generation pipeline.
Figure 3: Overview of DynaVid. (a) The motion generator first synthesizes motion and then produces video frames conditioned on the generated motion. For camera-controlled video synthesis, Plücker embeddings are provided as additional input. (b) Our framework adopts VACE [ 25 ] to incorporate control signals such as Plücker embeddings or optical flow maps.
Figure 4: Qualitative comparison of dynamic object motion generation. CogVideoX [ 56 ] and Wan2.2-5B [ 48 ] often produce distorted or unrealistic human motions with visual artifacts. HyperMotion [ 52 ] produces unnatural appearances because it relies on the first frame as input. In contrast, our method generates realistic videos with natural and highly dynamic motions.
Pexels
DynaVid-Human test
FVD ( ↓ )
A-Qual ( ↑ )
I-Qual ( ↑ )
M-Smooth ( ↑ )
T-Flick ( ↑ )
FVD ( ↓ )
A-Qual ( ↑ )
I-Qual ( ↑ )
M-Smooth ( ↑ )
T-Flick ( ↑ )
CogVideoX-5B
1519.54
0.5646
0.6613
0.9844
0.9673
2238.68
0.5071
0.5562
0.9779
0.9565
Wan2.2-5B
1172.02
0.5779
0.7235
0.9928
0.9883
1775.99
0.5389
0.6974
0.9904
0.9791
HyperMotion
420.82*
0.5578
0.6972
0.9922
0.9850
391.22*
0.5092
0.6265
0.9939
0.9914
Ours
1126.38
0.5807
0.7342
0.9900
0.9748
1351.94
0.5312
0.7352
0.9931
0.9864
Table 1: Quantitative evaluation of object motion generation on the Pexels [ 37 ] and DynaVid-Human test datasets, representing common and highly dynamic scenes, respectively. Our method achieves comparable or superior results on both datasets compared to other baseline methods. *: HyperMotion [ 52 ] uses a first frame as input, resulting in lower FVD scores due to the appearance similarity.
Figure 5: Qualitative comparison of camera-controlled video synthesis. Red arrows indicate the directions of camera motion. AC3D [ 1 ] fails to follow the extreme 180 ∘ rotation, while GEN3C [ 40 ] produces noticeable artifacts in regions unseen from the initial view (zoomed-in red box). In contrast, our method produces natural-looking videos that faithfully follow the input camera trajectory. For fair comparison, the same camera parameters are used for all methods.
RE10K test
DynaVid-Camera test
mRotErr ( ↓ )
FVD ( ↓ )
A-Qual ( ↑ )
I-Qual ( ↑ )
M-Smooth ( ↑ )
T-Flick ( ↑ )
mRotErr ( ↓ )
FVD ( ↓ )
A-Qual ( ↑ )
I-Qual ( ↑ )
M-Smooth ( ↑ )
T-Flick ( ↑ )
AC3D
0.1347
685.05
0.5184
0.6636
0.9918
0.9651
1.1529
782.01
0.4483
0.5407
0.9727
0.9403
GEN3C
0.0809
566.99*
0.4579
0.6079
0.9899
0.9731
1.1852
237.15*
0.3889
0.5659
0.9844
0.9611
Ours
0.1136
664.21
0.5425
0.7224
0.9888
0.9699
0.9289
674.72
0.4501
0.6713
0.9760
0.9487
Table 2: Quantitative evaluation of camera-controlled video synthesis on RE10K [ 61 ] and DynaVid-Camera, representing common and dynamic scenes, respectively. While achieving comparable rotation errors on common scenes, our method significantly outperforms other baseline methods on scenes with rapidly changing viewpoints. *: GEN3C [ 40 ] uses a first frame as input, resulting in lower FVD scores.
Pexels
DynaVid-Human test
FVD ( ↓ )
A-Qual ( ↑ )
I-Qual ( ↑ )
M-Smooth ( ↑ )
T-Flick ( ↑ )
FVD ( ↓ )
A-Qual ( ↑ )
I-Qual ( ↑ )
M-Smooth ( ↑ )
T-Flick ( ↑ )
Ours
1126.38
0.5807
0.7342
0.9900
0.9748
1351.94
0.5312
0.7352
0.9931
0.9864
w/o synthetic motion data (a)
(-49.85)
(-0.0199)
(-0.0156)
(-0.0002)
(-0.0019)
(+527.04)
(+0.0106)
(-0.0403)
(-0.0062)
(-0.0249)
w/o batch mixture (b)
(+759.36)
(-0.0073)
(-0.0070)
(+0.0030)
(+0.0144)
(-122.24)
(-0.0050)
(-0.0006)
(-0.0022)
(-0.0013)
w/o dataset filtering † (c)
(-33.79)
(+0.0011)
(+0.0035)
(+0.0007)
(+0.0009)
(+32.44)
(+0.0055)
(-0.0140)
(+0.0008)
(+0.0012)
w/ synthetic video data (d)
(+104.43)
(+0.0163)
(+0.0124)
(-0.0012)
(+0.0005)
(-653.98)*
(+0.0112)
(-0.0487)
(-0.0000)
(+0.0049)
Table 3: Ablation study of our main components, evaluating video and motion synthesis quality on the Pexels and DynaVid-Human test datasets. † : Our model without data filtering achieves comparable quantitative results but produces noticeably degraded visual quality in highly dynamic motion synthesis, as shown in Fig. 6 . *: Our model trained with rendered synthetic videos reports lower FVD scores, because it produces artificial appearances resembling synthetic data, as shown in Fig. 6 .
Figure 6: Visual examples of the ablation study. Our model without dataset filtering produces video frames that are inconsistent with the input motion (top). Our model trained using the synthetic video dataset reproduces the artificial look of rendered videos (bottom).
Clean
25dB
20dB
15dB
10dB
5dB
M-Err ( ↓ )
4.287
4.371
4.374
4.323
4.391
4.434
A-Qual ( ↑ )
0.5312
0.5233
0.5239
0.5148
0.5071
0.4632
Table 4: Error robustness of the motion-guided video generator.
Figure 7: Capability to synthesize non-human dynamic motions.
Figure 8: Limitations. Our method is less effective in generating videos with multiple people performing dynamic motions.