In this paper

we introduce a novel approach to as-rigid-as-possible mesh deformation based on tetrahedral cells. The most distinctive feature of this approach is that users can modify the original mesh by selecting a couple of vertices on the mesh. First

sets of tetrahedral cells are produced

which fit well to the mesh surface

through sparse voxelization. Preserving the rigidity of local transformations of the mesh surface and these tetrahedra during deformation is achieved by minimizing the corresponding energy formulation that prevents unnatural artifacts both on the surface and in the interior of the model. Meanwhile

in order to avoid the possible collapse emerged under large-scale deformation

we present a simple adaptive tetrahedron decomposition method

which brings more local deformation freedom to the interior of the mesh to eliminate the implausible deformation effects based on these dramatic volume changes in the local area. In addition

a few tetrahedra are generated by this method

and then more tetrahedral cells would be densely involved into the deformation process if necessary

there by resulting in highly efficient and robust results. In our experiments

we show that the volume and the surface details of the whole mesh can be approximately preserved and the local degeneration inside the mesh under the large-scale deformation could be efficiently avoided.