Terminology

terminology image

The Ziva Maya Plugin is intended for simulating creatures, and so we use terminology from biology and creatures.

solver
The code that couples the scene together and “solves” for the state of the dynamic physical system. This is exposed in the zSolver node.
creature
A collection of simulation components (bodies, attachments, etc) that are simulated together in one solver. The parts of a creature can physically interact with each other.
body (simulation body)
Bone, tissue, or cloth object.
soft body
General deformable elastic object – a tissue or cloth. The motion of a soft body is computed by the solver.
bone
A mesh that is not computed by the solver. The motion (and deformation) of the bones are inputs to the solver, and can be controlled with all the standard Maya tools.
tissue
A general deformable elastic object that has 3D thickness, e.g. muscles or fat. The motion of a tissue is computed by the solver.
cloth
A general deformable elastic object that is sheet-like, e.g. skin, fascia, or fabrics. The motion of a cloth is computed by the solver.
material
The physical properties of a body, such as its density and stiffness.
integrator
A numerical procedure that computes the positions, velocities and accelerations of the vertices of simulation bodies at the end of the timestep, based on their current positions, velocities and accelerations, using the specified material properties, attachments, current contacts, etc.
muscle fiber
Muscle fibers can be added to a tissue to enable it to contract and flex like a real muscle. How much it flexes is controlled by its excitation.
subtissue
A subtissue has all the properties that a tissue has, but applies those properties to its parent tissue rather than being its own independent elastic object.
attachment
A connection between bodies that attaches them together. They may be fixed (as if the bodies are stapled together) or sliding (as if the bodies are stuck in contact).
tetrahedral mesh
Each tissue is simulated as a low-resolution tetrahedral (tet) mesh. The deformations of the tissue are all due to deformations of the tet mesh, because the tissue’s triangle mesh is embedded in the tet mesh.
embedded mesh
Maya meshes may be embedded within a tissue (or cloth). The embedding makes the triangle mesh move with the tissue.
default solver
The solver to use for Ziva commands in case there are two or more solvers in the scene, in case of solver ambiguity. Useful in multi-solver workflows. Only affects Ziva commands in the presence of two or more solvers. All solvers always simulate when pressing Play.
rig
The set of all components that go into creating an animatable character. A typical Ziva rig includes geometry defining the shape of the anatomy (tissues, bones, fascias (cloth), etc.), as well as painted spatially-varying attachments between them, their material properties, collision properties, muscle firing properties, simulation solver settings, damping settings, etc. Often used interchangeably with setup.
setup
Used as a synonym for rig in the context of creating creatures in Maya with ZivaVFX.
anatomy transfer
The process whereby the geometry and Ziva rig of one creature is transferred from one creature onto another, for example, using the skins of the two creatures.
harmonic warping
A general-purpose variant of warping suitable for warping interior geometry. This warp minimizes distortion of the warped geometry.
bone warping
The process whereby bones are warped in a way that keeps them straight and preserves relative positions of important landmarks.
RBF warping
A variant of warping that uses Radial Basis Functions. It is especially suitable for warping geometry exterior of a creature, such as hair, eyelids and similar.
zBuilder
A python scripting toolset developed by Ziva Dynamics to faciliate Ziva character rigging. Available for download on Ziva Dynamics’s website. Ziva Anatomy Transfer technology uses the zBuilder to load/save/copy/paste/transfer/mirror Ziva rigs.
mirroring
A process whereby one designs the geometry of a complete creature, and the Ziva rig on one half of the creature. The other half of the rig can then be generated automatically using our Ziva rig mirroring (copy/paste with name substitution) tools, saving rigging time.
skin cluster
A Maya term referring to geometry being deformed using a Maya joint hierarchy. This is a Maya process, not a Ziva process. In a Ziva scene, it can be used to drive the geometry of the bones. Our warping tools can transfer the skin clusters from the source creature onto the target.
skin
The external mesh of a creature.
mesh registration
The process whereby a skin mesh of the target creature is brought into correspondence with the skin mesh of the source creature, so that the warping process can begin. Being in correspondence means having the same number of vertices, in the same order, and the same triangles on those vertices. Ziva Anatomy Transfer tools require registered skin and target meshes.
motion
The temporal sequence of joint angles in the joint hierarchy of the creature. This typically forms the input to the Ziva rig.
motion retargeting
The process whereby motion (of the joint hierarchy) is transferred from one creature onto another. This process is commonly done in industry, and is independent of Ziva. It can be done using any of the many existing tools for this purpose.