SOFA+Tearing -Plugin crashes in many scenes

[fishing602]

Hello forum and developers,

I am currently testing tearing plugin (v24.06) in the provided example scenes, and SOFA (also v24.06) just quit unexpectedly after I press the "Animate" button.
For example, when I open "scenes/TearingEngine/SquareTissue_01_gravity.scn", after a while it crashes. You can see the video I recorded here: record.webm

So is there any reason why SOFA crashes? Does it depend on value of parameters, which we can change in panel?

Another question is, what is the unit of the "fractureMaxLength" and "startLength"?

Best regards!

[epernod]

Hi,
could you copy past the full log of the crash here.
Regarding the unit, it is the same unit as the rest of your scene. I.e if you have a mesh of size == 1, a fractureMaxLength of 1 may cut the mesh totally.

Best regards,

[fishing602]

Hi epernod,

I forgot to say that all the crashes happen in SOFA on Ubuntu 22.04.
About the first question, I paste the log down here:

########## SIG 11 - SIGSEGV: segfault ##########
sofa::helper::BackTrace::sig(int)
sofa::component::topology::container::dynamic::TriangleSetGeometryAlgorithms<sofa::defaulttype::StdVectorTypes<sofa::type::Vec<3u, double>, sofa::type::Vec<3u, double>, double> >::SplitAlongPath(unsigned int, sofa::type::Vec<3u, double>&, unsigned int, sofa::type::Vec<3u, double>&, sofa::type::vector<sofa::geometry::ElementType, sofa::type::CPUMemoryManagersofa::geometry::ElementType >&, sofa::type::vector<unsigned int, sofa::type::CPUMemoryManager >&, sofa::type::vector<sofa::type::Vec<3u, double>, sofa::type::CPUMemoryManager<sofa::type::Vec<3u, double> > >&, sofa::type::vector<unsigned int, sofa::type::CPUMemoryManager >&, double, double)
sofa::component::TearingAlgorithms<sofa::defaulttype::StdVectorTypes<sofa::type::Vec<3u, double>, sofa::type::Vec<3u, double>, double> >::splitting(int, int, sofa::type::Vec<3u, double>, sofa::type::Vec<3u, double>, sofa::type::Vec<3u, double>, int, int, sofa::type::vector<sofa::geometry::ElementType, sofa::type::CPUMemoryManagersofa::geometry::ElementType >, sofa::type::vector<unsigned int, sofa::type::CPUMemoryManager >, sofa::type::vector<sofa::type::Vec<3u, double>, sofa::type::CPUMemoryManager<sofa::type::Vec<3u, double> > >, sofa::type::vector<unsigned int, sofa::type::CPUMemoryManager >&)
sofa::component::TearingAlgorithms<sofa::defaulttype::StdVectorTypes<sofa::type::Vec<3u, double>, sofa::type::Vec<3u, double>, double> >::algoFracturePath(sofa::type::Vec<3u, double>, unsigned int, sofa::type::Vec<3u, double>, sofa::type::Vec<3u, double>, unsigned int, sofa::type::Vec<3u, double>, sofa::type::vector<sofa::type::Vec<3u, double>, sofa::type::CPUMemoryManager<sofa::type::Vec<3u, double> > > const&)
sofa::component::engine::TearingEngine<sofa::defaulttype::StdVectorTypes<sofa::type::Vec<3u, double>, sofa::type::Vec<3u, double>, double> >::algoFracturePath()
sofa::simulation::PropagateEventVisitor::processNodeTopDown(sofa::simulation::Node*)
sofa::simulation::graph::DAGNode::executeVisitorTopDown(sofa::simulation::Visitor*, std::__cxx11::list<sofa::simulation::graph::DAGNode*, std::allocatorsofa::simulation::graph::DAGNode* >&, std::map<sofa::simulation::graph::DAGNode*, sofa::simulation::graph::DAGNode::StatusStruct, std::lesssofa::simulation::graph::DAGNode*, std::allocator<std::pair<sofa::simulation::graph::DAGNode* const, sofa::simulation::graph::DAGNode::StatusStruct> > >&, sofa::simulation::graph::DAGNode*)
sofa::simulation::graph::DAGNode::executeVisitorTopDown(sofa::simulation::Visitor*, std::__cxx11::list<sofa::simulation::graph::DAGNode*, std::allocatorsofa::simulation::graph::DAGNode* >&, std::map<sofa::simulation::graph::DAGNode*, sofa::simulation::graph::DAGNode::StatusStruct, std::lesssofa::simulation::graph::DAGNode*, std::allocator<std::pair<sofa::simulation::graph::DAGNode* const, sofa::simulation::graph::DAGNode::StatusStruct> > >&, sofa::simulation::graph::DAGNode*)
sofa::simulation::graph::DAGNode::doExecuteVisitor(sofa::simulation::Visitor*, bool)
sofa::simulation::DefaultAnimationLoop::propagateAnimateEndEvent(sofa::core::ExecParams const*, double) const
sofa::simulation::DefaultAnimationLoop::step(sofa::core::ExecParams const*, double)
sofa::simulation::node::animate(sofa::simulation::Node*, double)
sofa::gui::qt::RealGUI::step()
QTimer::timeout(QTimer::QPrivateSignal)
QObject::event(QEvent*)
QApplicationPrivate::notify_helper(QObject*, QEvent*)
QCoreApplication::notifyInternal2(QObject*, QEvent*)
QTimerInfoList::activateTimers()
g_main_context_dispatch
g_main_context_iteration
QEventDispatcherGlib::processEvents(QFlagsQEventLoop::ProcessEventsFlag)
QEventLoop::exec(QFlagsQEventLoop::ProcessEventsFlag)
QCoreApplication::exec()
sofa::gui::qt::RealGUI::mainLoop()
sofa::gui::common::GUIManager::MainLoop(boost::intrusive_ptrsofa::simulation::Node, char const*)
__libc_start_main
segment fault（core dump）

About the second question, I still can't understand what does it mean by "the same as the rest of my scene", is there any physical length unit such as meter or milimeter? Also what is the definition of the variable "size" you mentioned in your last sentence?

I tried to set fractureMaxLength to a lower value like 0.3, and SOFA didn't crash, but I think the tearing effect after draging the tissue(test_tearing.webm) is worse than that in the demo of tearing plugin(https://github.com/InfinyTech3D/Tearing/blob/main/doc/Tearing_mouse_interaction.gif).
Why I think the simulation effect on my computer is worse? -Becasue it has many floating triangles and multiple splits in a single tear, and the splits are not as smooth as your demo and have an overall jagged appearance.
So the third question is: How did you guys get such great simulation results?

It would be really nice if you can do some more explanation. Thank you!

[epernod]

Ok thank you, I will test it on ubuntu and let you know.
regarding the length. I meant it depends on your mesh size. For example if your mesh go from 0 to 10 in the X direction it could represent mm or cm or m. The fractureMaxLength Data will have the same unit.
So let's say in your mesh a triangle is ~1 unit of length. Putting fractureMaxLength equal to 2 or 2.5 will ensure your fracture 2 triangles per tearing effect.