Release Notes¶

Version 1.1¶

Add “rest-scale” to make cloth shrink like shrinkwrap (or grow).
Add “pressure” to apply an external pressure force to cloth. Pressure and rest-scale are useful for wrapping fascia around muscles.
Significant performance improvements to tetrahedralization. Previously, we have advised setting zTet.tetSize to a large value and using surface refinement and refinement propagation to get high resolution where you need it. That workaround is no longer necessary and will be slower than setting tet-size directly to what you want. Surface refinement should only be used if you actually want spatially-varying refinement.
Lazy license checkout. The plugin only acquires a license once a node or command is run, note when the plugin is loaded.
Mesh analysis checks for negative-volume (inverted normals), which will usually look fine, but completely breaks material attributes, particularly on subtissues.
Significant performance improvements to zFindIntersections command (menu item “Ziva Tools” -> “Find Intersections”).

The plugin won’t load in “maya -prompt” mode.
Random crashes due to invalid internal constraints on cloth.
Warnings about MEL variable-shadowing happen on plugin load.
Running mayapy is using an authoring license instead of a batch license.
A sliding attachment with a subtissue target crashes maya.
Unstable cloth when rest shape was folded over itself.
Save and Load zCache dialogs no longer filter for file type when set to “All Files”

Node	Attribute Change	Purpose
zMaterial	Add restScale and pressure	To support fascia simulation and more general cloth sims. In actual fact, restScale was present in 1.0, but it was undocumented and unsupported.
zCloth	Add restScaleEnvelope and pressureEnvelope	To support stable runup with restScale and pressure effects.

Fix crashes or incorrect behaviour when tissue tets are larger than 1 meter across.
Fix incorrect spurious attachment of cloth vertices to other nearby parts of the same cloth.

Add zLineOfAction to enable semi-automatic muscle fiber excitation.
SubTissues - for volumetric material authoring.
Add zPolyCombine - a fast poly combine node. We use this internally because the Maya polyCombine is much too slow.
Empty Cavities mode on zTet mesh allows users to create internal cavities in tet mesh. For example, when meshing a fat layer over the entire body, this mode will not fill the rest of the body cavity with material.
Increased accuracy of tissue mass and stiffness for tets partially outside the tissue surface. Depending on resolution, this can reduce object mass and jiggle relative to previous versions.
Cloth - our cloth material model is no longer experimental. It is significantly more stable than past releases. It’s not a general cloth solution yet, but it is good for simulating fascia and skin.
Muscle Excitation is now visualized with a fiber color change.
Automatic fiber endpoint selection when adding a fiber node. Manual painting is still recommended, but it will paint a default automatically.
Logging improvements. All logging has controllable verbosity. All logging goes to the script editor and a log file.
Lots of performance improvements, affecting:
- Simulation caching
- Collision detection and response
- Attachment updates
- Attachment creation
- Material interpolation
- zEmbedder

Fix memory leak affecting cloth, volume conservation, inertial damping, and hard attachments/contacts.
Fix out-of-bounds memory access during tetrahedralization.
Ziva Menus no longer attempting to load in Batch mode.
zBones no longer draw when disabled.
Fix random crash on Linux.

Node Change	Purpose
Add zLineOfAction	Automatic muscle fiber excitation
Add zPolyCombine	Fast alternative to Maya’s polyCombine

Node	Attribute Change	Purpose
zTissue	Add iParentTissue and oChildTissue	To support subtissues.
zTissue	Add serializedCache	To support fast re-opening of scenes. Internal use only.
zTet	Change fillInterior from bool to enum.	To support a new option ‘Empty Cavities’. See Tetrahedal Meshes
zTet	Remove tetsUpperBound. Add maxResolution.	Same purpose, but the new parameter is easier to explain and understand.
zEmbedder	Remove iSolverParams	No longer needed.
zCloth	Remove collisionVolume	This never worked anyway.
zIsoMesh	Add inputGeometry	To allow a faster and more accurate algorithm on watertight input meshes.

Command	Purpose
Add ziva -addSubtissue	To support subtissues
Add ziva -removeSubtissue	To support subtissues
Add ziva -lineOfAction	To enable automatic muscle excitation.
Add zLineOfActionUtil	To help make rigs for automatic muscle excitation.
Add zPolyCombine	To create the new zPolyCombine node.