Physics simulation for real-world reconstruction examples

[haonanhe]

I am curious about real-world reconstruction examples, such as hand, face, and whole-body reconstructions. How did you implement the physics simulation for these cases, or was physics simulation not used for these examples? For the reconstruction of balls bouncing on the ground, I understand the simulation part is easy to implement. However, it is difficult to design simulations for the hand, face, or whole body. If there is no physics simulation, then how could better results compared to other methods be achieved?