Real-Time Physics Simulation Forum

Glad you found your issue!

That's a common pattern, to make a list of thing you *want* to remove, then remove them in a second loop. I have that pattern in several places in my codebase.

To expound a bit on my theory... Take these two lines of code: const btCollisionObject* obA = contactManifold->getBody0(); ... void* usrDataB = obA->getUserPointer(); An example of what I'm talking about is: obA is a pointer to memory ... but maybe you freed that memory earlier in the program? If so...

C++ is hard. Touch memory wrong *just once* and things explode. In my experience (not just about Bullet, but with any C++ code) the most common issue is that you are sharing a pointer to some objects, the memory for that object gets freed ("delete" in C++) somewhere, but that pointer is st...

I noticed this comment in btRaycastVehicle. I dug through the git history to see where that comment came from ... turns out it has been there since 2006 in the first commit of the btRaycastVehicle. So, I'm hoping someone from the core team can provide some history or context ... why does btRaycastVe...

Bump! Many places on this forum link to the wiki (and such posts rely on the wiki to explain something), so there is a tremendous amount of knowledge lost right now.

Yep, I'm seeing the same behavior as @s_kohan. Even if there is a btPersistentManifold, you still have to check getNumContacts() > 0 to actually know if the collision is for-realz.

Yes, that's actually how I ran into this myself (except we're loading GLTF instead of FBX but whatever, conceptually the same). Actually I went ahead and am just using btTriangleMesh (implements btStridingMeshInterface ) and I'm just adding all triangles to one "part" (because that's a lim...

Here's the manual I was referring to: https://github.com/bulletphysics/bullet3/blob/395e17c7bf2fd1b906f41aa651bb145dcedeb873/docs/Bullet_User_Manual.pdf (middle-ish of page 14) Says, "The btBvhTriangleMeshShape can store multiple mesh parts. It keeps a triangle index and part index in a 32bit s...

The User's Manual says that a btBvhTriangleMeshShape can store "multiple mesh parts" (page 14). I studied the source of btTriangleMesh and it only uses one (1) "part" (i.e. only one entry goes into the `m_indexedMeshes` array). So, my question (I've tried studying the code deeper...

Thanks for following up with you solution, Octavius_Ace. Glad to hear it, and I'll give it a try soon to see if I can solve my own "constraint stretching" issues as well. Sidenote... You say: When objects get unrealistically large, I find the simulation becomes very 'floaty', Maybe this is...

I'm also very interested in knowing the answer to your questions. Hopefully someone who knows the multibody world can help us here.