.. _sec-zTissue: zTissue ------- This node specifies tissue-specific attributes. +----------------------------+--------------------------------------------------------------------------------+ | Attribute | Meaning | | | | +============================+================================================================================+ | **enable** | When disabled, removes this tissue and affiliated attachments from the solve. | +----------------------------+--------------------------------------------------------------------------------+ | **material** | Specifies the material model being used by this specific tissue. | | | The default material is "StVK". Other choices are: “NeoHookean”, "Corotational"| | | and “Anisotropic”. See the “Elastic materials” section for a description of the| | | different materials. | +----------------------------+--------------------------------------------------------------------------------+ | **compressionResistance** | This more accurately prevents per element compression than using | | | "poissonsRatio" on the zMaterial node. If this value is set too high, | | | instabilities can occur. The default value is safe, but can be increased | | | depending on your situation to better maintain volume. | | | | | | Also consider with zMaterial.volumeConservation, which prevents both | | | compression and expansion and is more stable. | | | | | | N.B. This attribute does not apply to the “Corotational” and “Anisotropic” | | | material models. | +----------------------------+--------------------------------------------------------------------------------+ | **transverseAnisotropy** | This parameter only applies to the “Anisotropic” material model. It controls | | | how much weaker the material is in the transverse (i.e., perpendicular) | | | direction to the muscle fibers. A value of 1.0 means that the material is | | | equally strong in all directions (i.e., isotropic material). A value of 0.1 | | | means that the material is 10x weaker in the direction perpendicular to the | | | muscle fiber, whereas a value of, say, 100, will generate a material that is | | | 100x stronger in the perpendicular direction. The muscle fiber is needed to | | | establish a direction of anisotropy. The muscle fiber does not actually need to| | | be activated. If it is not activated, one obtains a passive tissue that is | | | anisotropic. If activated, one obtains an anisotropic active muscle. | +----------------------------+--------------------------------------------------------------------------------+ | **iParentTissue** | When connected to another tissue, this tissue becomes a subtissue of that one. | +----------------------------+--------------------------------------------------------------------------------+ | **oChildTissue** | When connected to another tissue, that tissue becomes a subtissue of this one. | +----------------------------+--------------------------------------------------------------------------------+ | **inertialDamping** | Inertial damping is a non-physical effect useful to enhance stability or handle| | | non-physical inputs. Inertial damping prevents tissues from ‘feeling’ inertia | | | due to large-scale motions. Small-scale deformations still have all of their | | | inertia, so elastic waves travel through objects normally. Using this, tissues | | | can be subjected to extreme acceleration without tearing themselves apart. This| | | is very different from the mass and stiffness damping available on the zSolver | | | node. | +----------------------------+--------------------------------------------------------------------------------+ | **restScaleEnvelope** | Modulates the effect of zMaterial.restScale. | | | When envelope is zero, restScale has no effect. | | | When restScaleEnvelope is negative, the effect inverts - causing objects | | | to grow instead of shrink, or vice versa. | | | This attribute is keyable, unlike zMaterial.restScale. | +----------------------------+--------------------------------------------------------------------------------+ | **pressureEnvelope** | Multiplies the pressure force from zMaterial.pressure. | | | This attribute is keyable, unlike zMaterial.pressure. | +----------------------------+--------------------------------------------------------------------------------+ | **surfaceTensionEnvelope** | Multiplies the surface tension force from zMaterial.surfaceTension. | | | This attribute is keyable, unlike zMaterial.surfaceTension. | +----------------------------+--------------------------------------------------------------------------------+ | | This attribute is keyable, unlike zMaterial.pressure. | | **collisions** | Enables collision detection and response with this tissue. | +----------------------------+--------------------------------------------------------------------------------+ | **collisionVolume** | Vertices from bodies that intersect this tissue (provided this tissue is a | | | closed volume and not self intersecting) will be pushed out. | +----------------------------+--------------------------------------------------------------------------------+ | **selfCollisions** | Enables self-collision detection and response. | +----------------------------+--------------------------------------------------------------------------------+ | **hardContact** | [Deprecated in v1.5. Continues to work, but hidden from the Maya UI. May be | | | removed in a future version. New designs should use the default (isHard=off).] | | | When enabled, uses implicit hard contact forces - this is more numerically | | | stable but comes at the cost of generating a larger system matrix to solve. | +----------------------------+--------------------------------------------------------------------------------+ | **contactStiffness** | The stiffness of “softContact” springs. It controls the “hardness” of the | | | contact between the two objects. Lower values may cause intersections to occur | | | during contact, but will be more stable. Higher values will cause little or no | | | intersection, but may require “hardContact” to be enabled and/or more solver | | | substeps to be stable. | +----------------------------+--------------------------------------------------------------------------------+ | **contactStiffnessExp** | The power to which the value of the **“contactStiffness”** is raised. | +----------------------------+--------------------------------------------------------------------------------+ | **contactSliding** | When enabled, contacts are resolved with the freedom to slide tangentially. | +----------------------------+--------------------------------------------------------------------------------+ | **fields** | Maya fields that affect this tissue (for external forces). | +----------------------------+--------------------------------------------------------------------------------+