def gravity_center(self):
        """torch.Tensor: A tensor with center of each box."""
        bottom_center = self.bottom_center
        gravity_center = torch.zeros_like(bottom_center)
        gravity_center[:, :2] = bottom_center[:, :2]
        gravity_center[:, 2] = bottom_center[:, 2] + self.tensor[:, 5] * 0.5
        return gravity_center
torch.Tensor: A tensor with center of each box.
projects/mmdet3d_plugin/core/bbox/structures/lidar_box3d.py