I've been looking at bullet's softbody, and have a system working at this time (non volumetric). However one thing that's clear is the parameters hugely impact the simulation, and I can't find a good reference. The most useful resource I've found is this forum post, where Nathanael gives some helpful insight, however I still have some questions which I hope someone can answer:
1)No mention is given of btSoftBody::Material parameters m_kLST, m_kAST & m_kVST. I understand they are used for stiffness, but have no idea how the values are used... what are the value ranges and what does min/max stiffness mean?
2)I don't really get the different solvers we set iterations for. Position I think I understand, but I've no idea what velocity and drift solving do, and how they relate to VCF/Baumgarte.
3)Can a soft-body collide with itself? If so, would setting kSHR=0 be the preferred way to disable it?
4)How does kMT (pose matching coefficient) work? Pose-matching in general I don't quite get beyond the basics but that's another thread, for now I'm just interested in what exactly the value here does.
5)are there any guides out there which discuss recommended configurations to simulate real-life materials, e.g skin/rubber/cloth/etc?
Many thanks for any help and/or links to past answers to the same questions.