THE 3D DEFORMATION OF A MUSCULAR AESTHETIC UNIT HAS TO BE SUPERPOSED WITH THE DEFORMATION OF VISCO ELASTIC ELASTOMERS IN ANISOTROPE SPACES. To perform such 3D reshaping without volume or mass increasing, you need to work thinking always 3D using
Vectors are normal to the muscle layer. They need to make an angle of 90 grades with the face plans.
Tensors are following sense and direction of the muscular area.They stay in the plan of the face.They are called tensors per analogy of physics.
Components of a stress tensor
The angle between a vector and a tensor has to be usually 90 grades.