That’s what soft-body tries to encompass. You can’t just freeze and unfreeze a soft-body system to a rigid-body though as you’d end up with odd behaviour and a

That’s what soft-body tries to encompass. You can’t just freeze and unfreeze a soft-body system to a rigid-body though as you’d end up with odd behaviour and a non-trivial decomposition. How many rigid bodies is this soft body now? How are they constrained relative to one another? And how to decompose the new shape into suitable collision primitives? Simple mass-spring systems (like this) have issues with really stiff springs and high masses causing unrealistic responses even with a low time step but you can use approaches like XPBD which are stable. Changing the configuration of constraints is what causes the shape change. Most vehicle sims get really far with just using a rigid-body system and modelling the damage another way. It’s much computationally cheaper, much cheaper in terms of time to setup a vehicle and lets you maintain high fidelity in the driving model which is the bit most players care about.