3D Character Dynamics

In progress

1. Training data examples

We construct our training data by assigning randomized motions to a primitive, e.g. a sphere. All results in the later sections are predicted from the newtork trained on this dataset. We here provide three random motion examples of the sphere dataset. The color coding shows the dynamics.

Sphere (vtx#: 1015; motion: random; frames: 456):

2. Our Secondary Motion inference pipeline

Below is the basic pipeline of our method. Given the skinned animation mesh, we first build a uniform volumetric mesh and then set the constraints. At inference time, our network predics the secondary motion with respect to the input skinned volumetric mesh. Finally, we render the surface mesh interpolated from the predicted volumetric mesh.

3. Our results

Big vegas (Figure 1) (vtx#: 1468):

3.1 Homogeneous dynamics

Ortiz (vtx#: 1258; motion: cross jumps rotation; frames: 122):

Ortiz (vtx#: 1258; motion: jazz dancing; frames: 326)

Kaya (vtx#: 1417; motion: zombie scream; frames: 167)

Kaya (vtx#: 1417; motion: dancing running man; frames: 240)

3.2 Non-homogeneous dynamics

As described in Figure 6, we set three different material properties to the character. In the legend at the bottom of the video, the gray area is the constraint, the red area has lower stiffness and the pink area has higher stiffness.

Michelle (Figure 6) (vtx#: 1105; motion: cross jumps; frames: 122):

Michelle (vtx#: 1105; motion: gangnam style; frames: 371):

Big vegas (vtx#: 1468; motion; cross jumps rotation; frames: 122):

4. Ablation study and comparions

Big vegas (Figure 7) (vtx#: 1468; motion: hip hop dancing; frames: 283):

5. Limitations

As discussed in the Conclusion Section, if the local geometric detail of a character is significantly different to those seen during training, e.g., the main local structures in the ear regions of the mousey character don't appear in the volumetric mesh of the sphere for training, the quality of our output decreases. One potential avenue for addressing this is to design more general primitives for training, beyond the tetrahedralized sphere. A thorough study on the type of training primitives and motion sequences can be an interesting future direction.

Mousey (vtx#: 2303; motion: swing dancing; frames: 627):

6. Easter egg

15 different animations of five different characters with predicted secondary motion:

Thanks! Stay healthy and happy.