Introduction ************ .. image:: images/max_kick0162.png :width: 400px :align: right :alt: anatomy image In this documentation, we will provide you with the tools you’ll need to know in order to become an effective Character Engineer. Physics-Based Animation ======================= In the past, physics-based elastic character simulation systems have been available only to the most privileged and resourced game, animation and visual effects studios. This is no longer the case. We provide a streamlined interface for simulating the breadth of anatomical tissues responsible for the physical appearance of every living creature as well as plants and inanimate, but deformable objects like trees, bridges and beach balls. Why Use Physics-Based Animation? -------------------------------- We all want more realism in our graphics, but we also have an increased demand to create more and more content. The only way to achieve both is physics-based graphics techniques. Already widely used for cloth and fluid simulation, physics-based character simulation is the next natural step. Why Use the Finite Element Method? ---------------------------------- The finite element method (FEM) is the prevailing approach used to simulate elastic objects for engineering and scientific purposes. FEM is the most accurate, flexible, well-understood and stable of the continuum discretization strategies. It is capable of producing results that are faithful to materials of real-world objects. FEM results are mesh-independent, unlike mass-spring systems, which are mesh-dependent and don’t model any particular physical material with much accuracy. Ziva Creatures ============== We typically refer to the characters created with Ziva VFX as ":term:`creatures`." This is partly to communicate that a huge variety of characters are possible, from real-world humans and animals to fantastic beasts from your wildest imaginings. Creatures made with Ziva are best thought of as "real" physical beings with actual weight, volume and elastic properties. A creature consists of meshes modeling its anatomy (bones, muscles, fat, skin, etc.), as well as its elastodynamic, contact, and attachment properties (the :term:`Ziva rig`). Ziva VFX software simulates the creatures using physics based simulation (FEM). Anatomy Transfer ---------------- Since v1.6, Ziva VFX includes tools for :ref:`sec-AnatomyTransfer`. This technology makes it possible to create a creature once, and then re-purpose it for similar creatures. Using Ziva Anatomy Transfer, one can easily transfer a :term:`Ziva rig` and its internal anatomical meshes to a new creature, based solely on the new creature's external "skin" mesh. The transfer of the :term:`Ziva rig` is facilitated using our :ref:`sec-zBuilder` toolset, which is a set of Python tools to edit, copy, load and save Ziva rigs. Anatomy transfer greatly speeds up the design of new creatures, by making it possible to re-purpose existing creatures with minimal manual work.