FAQ in daily usage¶
This page provides explanations/solutions for some commonly asked questions regarding the Ziva VFX product. These issues can be:
Bugs not caused by Ziva VFX, but are related to its use.
Bugs/error messages that are benign and have no effect on Ziva VFX use.
Features that appear to be bugs but are not.
Signs of a misconfiguration.
Solver Reports Error when Applying 1.0 Inertial Damping to a Standalone Tissue¶
Phenomenon:
Solver complains about invalid system when applying full inertial damping
to a standalone tissue without attachments under gravity:
ERR| Creature timestep failed due to exception: Invalid input system
Cause:
Inertial damping reduces the inertia in the system; applying 1.0 inertial damping removes the inertia and
makes it similar to a quasi-static problem where the solution is a static equilibrium state.
However, a tissue that falls freely under gravity has no static equilibrium state, so the solver fails to find a solution.
Solution:
This use case is invalid and should be avoided.
When 100% inertial damping is desired the tissue needs attachments to bones.
Please check QuasiStatic notes under Integrators section.
Re-simulation May Explode after Switching Solvers¶
Phenomenon:
Simulation can explode when rewinding to the start frame then re-simulating the scene with a different solver selected.
Cause:
Creature information is not properly reset after rewinding to start frame when a new solver is created.
Solution:
Rebuild the scene via cmds.ziva(refresh=True) after rewinding to start frame if the solver explodes.
Ziva VFX version 2.2 plugin can’t load under Linux¶
Phenomenon:
Can’t load Linux plugin.
Maya Script Editor outputs following error message complaining missing libcusparse, libcudart, or libcublas:
libcusparse.so.11: cannot open shared object file: No such file or directory
Cause:
The Maya module file doesn’t append shared file folder to the LD_LIBRARY_PATH environment variable,
which causes this issue.
We need to set the path manually before launching Maya.
Solution:
Refer to Linux Quick Installation for this extra installation step.
Save Ziva VFX Setup at Non-start Frame¶
Phenomenon:
The Maya Script Editor shows the following error message in isolation when opening a Ziva VFX setup:
ERR| Failure in creature solver. Creature is null.
ERR| zEmbedder zEmbedder1 - solver output creature is null
Cause:
The current frame does not match the start frame in the zSolverTransform node.
Solution:
Rewind to the start frame and save the setup.
Loading the Wrong Ziva VFX Maya Version¶
Phenomenon:
When manually loading a Ziva VFX plugin, the Maya Script Editor shows the following error message:
// Error: line 1: The specified procedure could not be found.
Cause:
The Ziva VFX Plugin version does not match the Maya version
(for example, attempting to load the Maya 2019 Ziva plugin into Maya 2022 will cause this error).
Solution:
Make sure that the Ziva VFX and Maya versions match.
A safer method is to load the plugin through the Maya Plugin Manager
(which can be found at Windows → Settings/Preferences → Plug-in Manager).
Tissue object has no tet mesh¶
Phenomenon:
When pasting a copied Ziva rig, the Maya script editor shows the following error message:
ERR| failed to create creature due to exception: Tissue has no tet mesh. #
Cause:
This is a known bug caused by the Maya node evaluation order.
The zSolver node is disabled and re-enabled during the paste operation.
When the zSolver node is re-evaluated, the evaluation order is reversed,
causing the tet mesh to be used before it is prepared.
Solution:
This problem corrects itself on a second pass, thus the error message can be ignored.