Real-Time Physics Simulation Forum

last time I had crazy jittering and wonky behavior on a heightfield, it turned out I was calling my GenerateTerrain() function twice and it was overwriting memory already allocated to bullet

regarding bullet to opengl, I stole this from a forum somewhere glm::mat4 bulletToGlm(const btTransform& t) { glm::mat4 m(0); const btMatrix3x3& basis = t.getBasis(); // rotation for (int r = 0; r < 3; r++) { for (int c = 0; c < 3; c++) { m[c][r] = basis[r][c]; } } // traslation btVector3 or...

as far as I know you could also just do this once and be done with it:

this is how I call stepSimulation (in both my hacky playground project, and my actual hobby game project) simTime = glfwGetTime(); dynamicsWorld->stepSimulation(deltaTime, 20, 1./100); dynamicsWorld->synchronizeMotionStates(); //if I remember correctly this was for the btRaycastVehicle's wheels if (...

I have an "opengl / bullet physics playground" project in visual studio that I try new things in, so the code is very hacky and ugly, but this is what works normally for me: // Build the broadphase //btBroadphaseInterface* broadphase = new btAxisSweep3(btVector3(0,-3,0), btVector3(TERRAIN_...

update: above wasn't working so I gave it another shot using your suggestion + the tutorial on bulletphysics.org this is what I'm doing: enum collisionGroups // http://www.bulletphysics.org/mediawiki-1.5.8/index.php/Collision_Filtering { COL_NOTHING = 0, //<Collide with nothing COL_GROUND = BIT(0), ...

try this:

ground:
restitution = 0.0
friction = 1.0

objects:
restitution = 0.3
friction = 0.5

make sure you don't have sleeping disabled for the objects (make sure you did not myRigidBody->setActivationState(DISABLE_DEACTIVATION); )

thanks for the mini-tutorial, it's hard to find good understandable info on this I think I've managed to sort it out for now but I will certainly add your example into the comments of my code for later use (I know I'll be back to it soon) - as a point of reference this is my simple little game: http...

okay thanks, I'll try to figure this out two questions: - does this mean I now have to set collision groups on everything? never used them before and was hoping for an easy way to do what I want without them. Why is this only happening now that I set the ghost object to be a sensortrigger? - is ther...

Thanks for the help - this makes sense -old post removed- Edit: with your help I was able to get rayTest to avoid the trigger ghost object, but now the ghost object is detecting the terrain in its collision manifold! (wasting CPU cycles) any tips on how I can avoid this? this is how I'm doing it now...

Hi, I've been reading through documentation and forum posts, and am having trouble figuring out how to do this: some of my units (turrets), have a cylinderShape ghost object around them that I'm using as a trigger to start targeting enemies inside of it This works perfectly, however now when I do a ...

I'm still very new to this, but an idea comes to mind: in btCollisionWorld.cpp , check out this area: /// for polyhedral shapes if (shape->isPolyhedral()) { btPolyhedralConvexShape* polyshape = (btPolyhedralConvexShape*) shape; int i; if (polyshape->getConvexPolyhedron()) { const btConvexPolyhedron*...

Hi, I'm investigating whether there's a super easy way to have Bullet run multithreaded in my simple game I'm building, I've done investigating and found the following: - Lunkhound forked a version specifically for this around 2014. I see that he is still updating his fork - is this the version to u...

edit: 7/4/2018 - this post was wrong, so I'm editing this in case any future person is here looking for a fix AFTER you call StepSimulation, and you're ready to draw your vehicle, do the following: vehicle->getRigidBody()->getMotionState()->getWorldTransform(buggyPosition); vehicle->updateWheelTrans...

Hi, I know this is an old thread but I'm having the same issue, the strange thing is the behavior of Bullet is seemingly random one time when I run the program, everything will run perfectly the next time, the objects will fall to the ground and start jiggling forever the next time, I'll get this bt...