Hi,

I have enabled assertions recently in our game and hit an assertion, looks like a possible memory corruption to me if assertions are disabled. The assertion is hit at:

• https://github.com/andreasdr/tdme2/blob/master/ext/reactphysics3d/src/collision/broadphase/DynamicAABBTree.h#L271

It happens when trying to check if a player can spawn using this logic:

• https://github.com/andreasdr/tdme2/blob/master/src/tdme/engine/physics/World.cpp#L386

Any ideas? We had a related bug before but you fixed it.

Many thanx and

Best regards Andreas

HI,

sometimes in like 2/8 cases objects fall through ConcaveMeshShape. In my case the bounding volumes are just BoxShapes.

I have an example video where you can see the issue:

• https://www.youtube.com/watch?v=hCFecUVEDQs&feature=youtu.be

I can provide another video if interested.

Many thanx and

Best regards Andreas

Hi, I started using this library yesterday to help with my undergrad dissertation. I've been enjoying the library but getting tons of segmentation faults. I'm on macOS 10.15.7 using XCode.

tid_307 (1): EXC_BAD_ACCESS (code=EXC_I386_GPFLT)

This was very prevalent with my first implementation of the physics code. I need to test whether bunch of voxels collide with a mesh, so was creating a box shape and collider body for each voxel. This code produced tons of segmentation faults.

I've since changed the code to use one box shape and collider, and purely move the transform to each voxel. However, with this change I now get an assertion fail:

assert(contactPoints[i].size() == 0);

This assertion only triggers on the 5th/6th voxel, however, which makes the problem even stranger. However, I assume it just happens that the 5th/6th voxel is actually colliding so there's a difference in the methods. Ie, for the first few voxels, there's no collision so no contact points. But for the 5th or 6th, it's colliding so there are collision points.

And if I comment out the assertion, I get more segmentation faults from this code.

mCollidersComponents.mCollisionShapes[i]->computeAABB(aabb, transform * mCollidersComponents.mLocalToBodyTransforms[i]);

To note about the segmentation faults, they've happened in multiple places and it doesn't seem to be one problematic line of code. However, there seems to be a similarity in that it's related to the entity component system / pointers to entities.

Segmentation Fault Stack Trace

#0	0x000000015184d383 in reactphysics3d::BroadPhaseSystem::updateCollidersComponents(unsigned int, unsigned int, float) at OpenPL/External/ReactPhysics3D/src/systems/BroadPhaseSystem.cpp:180
#1	0x000000015184d0fc in reactphysics3d::BroadPhaseSystem::updateCollider(reactphysics3d::Entity, float) at OpenPL/External/ReactPhysics3D/src/systems/BroadPhaseSystem.cpp:122
#2	0x00000001517b4894 in reactphysics3d::CollisionDetectionSystem::updateCollider(reactphysics3d::Entity, float) at OpenPL/External/ReactPhysics3D/include/reactphysics3d/systems/CollisionDetectionSystem.h:435
#3	0x00000001517b46de in reactphysics3d::CollisionBody::updateBroadPhaseState(float) const at OpenPL/External/ReactPhysics3D/src/body/CollisionBody.cpp:233
#4	0x00000001517b543d in reactphysics3d::CollisionBody::setTransform(reactphysics3d::Transform const&) at OpenPL/External/ReactPhysics3D/src/body/CollisionBody.cpp:398
#5	0x0000000151892065 in PL_SCENE::FillVoxels() at OpenPL/Source/Private/Objects/Private/PL_SCENE.cpp:415
#6	0x00000001518907b8 in PL_SCENE::Voxelise(PLVector, PLVector, float) at OpenPL/Source/Private/Objects/Private/PL_SCENE.cpp:308
#7	0x00000001519f7406 in ::PL_Scene_Voxelise(PL_SCENE *, PLVector *, PLVector *, float) at OpenPL/Source/Private/OpenPL.cpp:109

Assertion Stack Trace

#4	0x0000000156f21aa8 in reactphysics3d::NarrowPhaseInfoBatch::clear() at OpenPL/External/ReactPhysics3D/src/collision/narrowphase/NarrowPhaseInfoBatch.cpp:133
#5	0x0000000156f2033a in reactphysics3d::NarrowPhaseInfoBatch::~NarrowPhaseInfoBatch() at OpenPL/External/ReactPhysics3D/src/collision/narrowphase/NarrowPhaseInfoBatch.cpp:47
#6	0x0000000156f20545 in reactphysics3d::NarrowPhaseInfoBatch::~NarrowPhaseInfoBatch() at OpenPL/External/ReactPhysics3D/src/collision/narrowphase/NarrowPhaseInfoBatch.cpp:46
#7	0x0000000156f87416 in reactphysics3d::NarrowPhaseInput::~NarrowPhaseInput() at OpenPL/External/ReactPhysics3D/include/reactphysics3d/collision/narrowphase/NarrowPhaseInput.h:54
#8	0x0000000156f86a05 in reactphysics3d::NarrowPhaseInput::~NarrowPhaseInput() at OpenPL/External/ReactPhysics3D/include/reactphysics3d/collision/narrowphase/NarrowPhaseInput.h:54
#9	0x0000000156f9f7df in reactphysics3d::CollisionDetectionSystem::testOverlap(reactphysics3d::CollisionBody*, reactphysics3d::CollisionBody*) at OpenPL/External/ReactPhysics3D/src/systems/CollisionDetectionSystem.cpp:1478
#10	0x0000000156f803be in reactphysics3d::PhysicsWorld::testOverlap(reactphysics3d::CollisionBody*, reactphysics3d::CollisionBody*) at OpenPL/External/ReactPhysics3D/src/engine/PhysicsWorld.cpp:303
#11	0x0000000156fd9068 in PL_SCENE::FillVoxels() at OpenPL/Source/Private/Objects/Private/PL_SCENE.cpp:419
#12	0x0000000156fd7798 in PL_SCENE::Voxelise(PLVector, PLVector, float) at OpenPL/Source/Private/Objects/Private/PL_SCENE.cpp:308
#13	0x000000015713e3e6 in ::PL_Scene_Voxelise(PL_SCENE *, PLVector *, PLVector *, float) at OpenPL/Source/Private/OpenPL.cpp:109

My Code The code is slightly stripped down but still contains the core logic.

// Create box collider at origin. Will get moved later
CollisionBody* VoxelBody = PhysicsWorld->createCollisionBody(Transform::identity());
BoxShape* VoxelShape = PhysicsSystem->createBoxShape(Vector3(VoxelHalfSize, VoxelHalfSize, VoxelHalfSize));
VoxelBody->addCollider(VoxelShape, Transform::identity());

std::unique_ptr<TriangleVertexArray> TriangleArray (new TriangleVertexArray(static_cast<unsigned int>(Mesh.Vertices.cols()),
                                                                     Mesh.Vertices.data(),
                                                                     3 * sizeof(double),
                                                                     static_cast<unsigned int>(Mesh.Indices.cols()),
                                                                     Mesh.Indices.data(),
                                                                     3 * sizeof(int),
                                                                     TriangleVertexArray::VertexDataType::VERTEX_DOUBLE_TYPE,
                                                                     TriangleVertexArray::IndexDataType::INDEX_INTEGER_TYPE));
        
TriangleMesh* TriangleMesh = PhysicsSystem->createTriangleMesh();
TriangleMesh->addSubpart(TriangleArray.get());
        
ConcaveMeshShape* ConcaveMesh = PhysicsSystem->createConcaveMeshShape(TriangleMesh);
        
CollisionBody* MeshBody = PhysicsWorld->createCollisionBody(Transform::identity());
MeshBody->addCollider(ConcaveMesh, Transform::identity());

for (int i = 0; i < MeshCells->size(); i++)
{
    auto& Cell = (*MeshCells.get())[i];
            
    Eigen::Vector3d Pos = Cell->WorldPosition;
    Transform VoxelTransform = Transform::identity();
    VoxelTransform.setPosition(Vector3(Pos.x(), Pos.y(), Pos.z()));
    VoxelBody->setTransform(VoxelTransform);

    if (PhysicsWorld->testOverlap(MeshBody, VoxelBody))
    {
        Cell->Absorptivity = 0.75f; // DEBUG. TODO: Fill this with an actual value
    }
}

I've just done a little more testing and there are no problems if I use a box shape for the mesh body. It seems the concave mesh shape is the problem.

I understand concave mesh collision is expensive but I was hoping to have a "one size fits all" solution. As time isn't really a concern, I hoped a concave mesh could work for all meshes I throw at it.

You can view my roughly up to date code at: https://github.com/KarateKidzz/OpenPL

Hi @DanielChappuis

I have created a isolated test, written in TDME2, that shows random behaviour of RayCasting in RP3D. This test uses no multithreading or something, its just a basic single threaded test.

See here:

• https://github.com/andreasdr/tdme2/blob/master/src/tdme/tests/RayTracingTest.cpp

You can build and start with:

• make clean && make -j hardware_threads mains
• ./bin/tdme/tests/RayTracingTest (from main tdme2 folder)

You can find my raytracing logic here:

• https://github.com/andreasdr/tdme2/blob/master/src/tdme/engine/physics/World.cpp#L355

Expected would be that interaction table will be raytraced from bottom to top, but sometimes it only works on the upper OBB part or sometimes even not at all We have similar issues with other shapes, but lets start with this one.

You can change "player" X, Y rotation with mouse dragging and move with A,W,S,D keys.

If you have any questions or something please tell me. As this happens randomly I suggest no error in TDME2 but I can check deeper if required.

Many thanx and best regards Andreas

Hi Daniel

I am trying a game scene which works using v0.7.0, but when I swap to the latest master I get the following assert.

The assert originates from a NaN lenght of the quaternion.

(gdb) frame 4 #4 0x000000000063f22c in reactphysics3d::Quaternion::getUnit (this=0x1462184) at /src/mathematics/Quaternion.h:266 266 assert (lengthQuaternion > MACHINE_EPSILON); (gdb) info locals lengthQuaternion = -nan(0x400000) PRETTY_FUNCTION = "reactphysics3d::Quaternion reactphysics3d::Quaternion::getUnit() const"

#5 0x000000000063ce05 in reactphysics3d::DynamicsWorld::updateBodiesState (this=0x993820) at /src/engine/DynamicsWorld.cpp:222 222 bodies[b]->mTransform.setOrientation(mConstrainedOrientations[index].getUnit()); (gdb) info locals index = 2 b = 0 bodies = 0x1427e90 islandIndex = 0

It doesnt take many in game ticks before my simulation, which is 15 kinetic bodies attached by simple hinge joints and a floor polygon, to "blow up" and go crazy. Are there any settings or easy tweaks to improve the stability of the simulation?

Thanks.

I am trying to create a square pyramid as a polyhedron mesh - 4 outer triangular faces and two base triangular faces.

I am able to successfully create the polygon vertex array, but I am having problems with the polyhedron creation stage.

I am following the progression of shape creation as outlined in the user manual.

I would appreciate help with this! Thanks

Hi, I am trying to create a linked list of all the contact manifold points using your documentation:

//add contact manifold to the linked list, IF the two shapes overlap (aabb check) rp3d::List<const rp3d::ContactManifold*> manifolds;

// Get all the contacts of the world manifolds = dynamicsWorld->getContactsList(); rp3d::List<const rp3d::ContactManifold*>::iterator it;

// For each contact manifold for (it = manifolds.begin(); it != manifolds.end(); ++it) { const rp3d::ContactManifold* manifold = *it;

but my team and I are running into an error at this piece:

 error: ‘iterator’ is not a member of ‘reactphysics3d::List<const reactphysics3d::ContactManifold*>’

         rp3d::List<const rp3d::ContactManifold*>::iterator it;

Any help would be great!

hello, when I test HingeJoint, there are two shapes in the righidbody, and the rigid body connect a static rigid body. the dynamic rigid body rotate around z axis, and anchor point is(-1, 0, 0). it works but the dynamic rigid body's position is wrong, I expect the position is (0,0,0) in original. but the position is (0.5,0,0). it is not the same as the Position in Unity3d.
So, I do things like below: rp3d::WorldSettings settings; settings.defaultPositionSolverNbIterations = 0; the original(or Init) position is right, but the anchor point has some offset, not I respected.

All in all , when I export unity physics data, and import the data to my app. the hingeJoint simulate result is not right.

hello!

1. How Can I implement OnCollisionEnter(), OnCollisionExit(); OnCollisionStay(), OnTriggerEnter(), OnTriggerExit(); OnTriggerStay() as the same with unity3d?

On installing on ubuntu linux 18.04 I get the following install messages

Install the project... -- Install configuration: "Release" -- Installing: /usr/local/lib/libreactphysics3d.so.0.7.1 -- Installing: /usr/local/lib/libreactphysics3d.so.0.7 -- Installing: /usr/local/lib/libreactphysics3d.so -- Installing: /usr/local/include/reactphysics3d/configuration.h -- Installing: /usr/local/include/reactphysics3d/decimal.h -- Installing: /usr/local/include/reactphysics3d/reactphysics3d.h -- Installing: /usr/local/include/reactphysics3d/Body.h -- Installing: /usr/local/include/reactphysics3d/CollisionBody.h -- Installing: /usr/local/include/reactphysics3d/RigidBody.h -- Installing: /usr/local/include/reactphysics3d/ContactPointInfo.h -- Installing: /usr/local/include/reactphysics3d/ContactManifoldInfo.h -- Installing: /usr/local/include/reactphysics3d/BroadPhaseAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/DynamicAABBTree.h -- Installing: /usr/local/include/reactphysics3d/CollisionDispatch.h -- Installing: /usr/local/include/reactphysics3d/DefaultCollisionDispatch.h -- Installing: /usr/local/include/reactphysics3d/VoronoiSimplex.h -- Installing: /usr/local/include/reactphysics3d/GJKAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/SATAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/NarrowPhaseAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/SphereVsSphereAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/CapsuleVsCapsuleAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/SphereVsCapsuleAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/SphereVsConvexPolyhedronAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/CapsuleVsConvexPolyhedronAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/ConvexPolyhedronVsConvexPolyhedronAlgorithm.h -- Installing: /usr/local/include/reactphysics3d/AABB.h -- Installing: /usr/local/include/reactphysics3d/ConvexShape.h -- Installing: /usr/local/include/reactphysics3d/ConvexPolyhedronShape.h -- Installing: /usr/local/include/reactphysics3d/ConcaveShape.h -- Installing: /usr/local/include/reactphysics3d/BoxShape.h -- Installing: /usr/local/include/reactphysics3d/CapsuleShape.h -- Installing: /usr/local/include/reactphysics3d/CollisionShape.h -- Installing: /usr/local/include/reactphysics3d/ConvexMeshShape.h -- Installing: /usr/local/include/reactphysics3d/SphereShape.h -- Installing: /usr/local/include/reactphysics3d/TriangleShape.h -- Installing: /usr/local/include/reactphysics3d/ConcaveMeshShape.h -- Installing: /usr/local/include/reactphysics3d/HeightFieldShape.h -- Installing: /usr/local/include/reactphysics3d/RaycastInfo.h -- Installing: /usr/local/include/reactphysics3d/ProxyShape.h -- Installing: /usr/local/include/reactphysics3d/TriangleVertexArray.h -- Installing: /usr/local/include/reactphysics3d/PolygonVertexArray.h -- Installing: /usr/local/include/reactphysics3d/TriangleMesh.h -- Installing: /usr/local/include/reactphysics3d/PolyhedronMesh.h -- Installing: /usr/local/include/reactphysics3d/HalfEdgeStructure.h -- Installing: /usr/local/include/reactphysics3d/CollisionDetection.h -- Installing: /usr/local/include/reactphysics3d/NarrowPhaseInfo.h -- Installing: /usr/local/include/reactphysics3d/ContactManifold.h -- Installing: /usr/local/include/reactphysics3d/ContactManifoldSet.h -- Installing: /usr/local/include/reactphysics3d/MiddlePhaseTriangleCallback.h -- Installing: /usr/local/include/reactphysics3d/BallAndSocketJoint.h -- Installing: /usr/local/include/reactphysics3d/ContactPoint.h -- Installing: /usr/local/include/reactphysics3d/FixedJoint.h -- Installing: /usr/local/include/reactphysics3d/HingeJoint.h -- Installing: /usr/local/include/reactphysics3d/Joint.h -- Installing: /usr/local/include/reactphysics3d/SliderJoint.h -- Installing: /usr/local/include/reactphysics3d/CollisionWorld.h -- Installing: /usr/local/include/reactphysics3d/ConstraintSolver.h -- Installing: /usr/local/include/reactphysics3d/ContactSolver.h -- Installing: /usr/local/include/reactphysics3d/DynamicsWorld.h -- Installing: /usr/local/include/reactphysics3d/EventListener.h -- Installing: /usr/local/include/reactphysics3d/Island.h -- Installing: /usr/local/include/reactphysics3d/Material.h -- Installing: /usr/local/include/reactphysics3d/OverlappingPair.h -- Installing: /usr/local/include/reactphysics3d/Timer.h -- Installing: /usr/local/include/reactphysics3d/Timer.cpp -- Installing: /usr/local/include/reactphysics3d/CollisionCallback.h -- Installing: /usr/local/include/reactphysics3d/OverlapCallback.h -- Installing: /usr/local/include/reactphysics3d/mathematics.h -- Installing: /usr/local/include/reactphysics3d/mathematics_functions.h -- Installing: /usr/local/include/reactphysics3d/Matrix2x2.h -- Installing: /usr/local/include/reactphysics3d/Matrix3x3.h -- Installing: /usr/local/include/reactphysics3d/Quaternion.h -- Installing: /usr/local/include/reactphysics3d/Transform.h -- Installing: /usr/local/include/reactphysics3d/Vector2.h -- Installing: /usr/local/include/reactphysics3d/Vector3.h -- Installing: /usr/local/include/reactphysics3d/Ray.h -- Installing: /usr/local/include/reactphysics3d/MemoryAllocator.h -- Installing: /usr/local/include/reactphysics3d/DefaultPoolAllocator.h -- Installing: /usr/local/include/reactphysics3d/DefaultSingleFrameAllocator.h -- Installing: /usr/local/include/reactphysics3d/DefaultAllocator.h -- Installing: /usr/local/include/reactphysics3d/MemoryManager.h -- Installing: /usr/local/include/reactphysics3d/Stack.h -- Installing: /usr/local/include/reactphysics3d/LinkedList.h -- Installing: /usr/local/include/reactphysics3d/List.h -- Installing: /usr/local/include/reactphysics3d/Map.h -- Installing: /usr/local/include/reactphysics3d/Set.h -- Installing: /usr/local/include/reactphysics3d/Pair.h -- Installing: /usr/local/include/reactphysics3d/Profiler.h -- Installing: /usr/local/include/reactphysics3d/Logger.h

However when linking the library into a project it expects the header files in the subdirectories. For example:

/usr/local/include/reactphysics3d/configuration.h:36:10: fatal error: containers/Pair.h: No such file or directory #include "containers/Pair.h"

Thanks!

` class OnOverlap : public OverlapCallback { public: int pos = 0; virtual void onOverlap (CallbackData& callbackData) { for (uint32 i = 0; i < callbackData.getNbOverlappingPairs (); i++) { OverlapPair pair = callbackData.getOverlappingPair (i); DG ("[%i] onOverlap. EventType: %i\n", pos, pair.getEventType ()); } } };

TEST_METHOD (Collide_NonRB_NonRB)
{
    PhysicsCommon physicsCommon; 
    PhysicsWorld* world = physicsCommon.createPhysicsWorld ();
    SphereShape* spShape = physicsCommon.createSphereShape (2.0f);

    CollisionBody* bodyA = world->createCollisionBody (rp3d::Transform::identity());
    bodyA->setTransform (Transform ({0,0,0}, Quaternion::identity ()));
    var collider = bodyA->addCollider (spShape, Transform::identity ());

    CollisionBody* bodyB = world->createCollisionBody (rp3d::Transform::identity ());
    bodyB->setTransform (Transform ({0,0,0}, Quaternion::identity ()));
    collider = bodyB->addCollider (spShape, Transform::identity ());

    OnOverlap overlapHandler;
    for (int i = -5; i < +5; i++)
    {
        overlapHandler.pos = i;
        // move bodyB to +X   
        bodyB->setTransform (Transform ({(float)i,0,0}, Quaternion::identity ()));
        world->testOverlap (overlapHandler);
        world->update (1);
    }
}`

getEventType() from callback, will return only OverlapStart. No OverlapStay, no OverlapExit - only enter. Please, comment it.

Hey,

my question is a bit of an odd one. Is it possible to, for example, vertically scale all physics objects? I'm trying to recreate physics of a fairly old game and one of its techniques was to scale the physics to 0.65 on the up axis to allow an easier movement across slopes (of any dynamic rigidbody). This sounds a bit dumb but actually works quite well with everything.

If it's not possible, i'd appreciate any idea that could point me into the correct direction (that still helps me accomplish the above 1:1), sorry for this weird topic.

Greetings

Good day, sorry if this is a beginner question I want to use reactphysics3d in my project , and I need to detect collision between 'walls' and convex object, I was wondering if there is some function which accepts an orientation matrix computed somewhere else, since i am not using quaternion.

Hi Daniel,

I want to simulate a fragile object. if other object hit this object with big Force(or fast Velocity), the fragile object will broke into pieces, otherwise the object is a normal rigid body.

Currently I have not write any code to test. My basic idea is two parts for fragile object: a normal rigid body and a trigger around it. When the trigger is triggered, calculate the velocity of hitting object, if it bigger than the limit velocity, then play the broke into pieces animation.

I want to known if my idea is ok. Do you have any advice? Thank you.

Hi everyone, I am trying to use this engine in my game project, and I am not sure what is the correct way to support players' input. If anyone have any good advice, please tell me. Thank you.

In my game, players can control a Role (a Capsule in physic world). A joystick controller are used to control direction, and a button is used to do jump action.

Move

I tried 3 solutions, but seems none of them is a good way.

1. add a force to the player's capsule with input direction.

auto force = 5.0f;
role->applyWorldForceAtCenterOfMass(direction * force);

world->update(timeStep);

The problem is that if player input the same direction continually, the capsule's velocity will keep growing and will not stop even player input an empty direction. so I should change other setting to fix it? maybe inertia, I am not sure.

2. calculate move delta, and set position to role rigidbody

double playerVelocity = 8.0f
auto posDelta = direction * timeStep * playerVelocity;

auto trans = role->getTransform();
trans.setPosition(trans.getPosition() + posDelta);
role->setTransform(trans);

world->update(timeStep);

The problem is that CollisionDetection not works well. We can see two Rigidbodys are part of overlap to each other, but actually the second object should be pushed off without any overlap. Maybe playerVelocity is so big. I don't know why.

3. set Velocity

direction.normalize();
auto vel = direction * playerVelocity;
role->setLinearVelocity(vel);

world->update(timeStep);

This way can push other rigidbogy off. But the role not stop immediately when player input empty direction. If user keep input the same direction, the role will keep same velocity and glide into the air.

Jump

add force to up direction, I don't know if this ok.

 Vector3 playerJumpForce{0, 500, 0};
role->applyWorldForceAtCenterOfMass(playerJumpForce);

world->update(timeStep);

Turn around

Seem as move, I not sure which is the right way.

1. set origention

auto trans = role->getTransform();
trans.setOrientation(Quaternion{x,y,z,w});
role->setTransform(trans);

world->update(timeStep);

2. apply Torque

role->applyWorldTorque(Vector3{x,y,z});

world->update(timeStep);

3. set AngularVelocity

role->setAngularVelocity(Vector3{x,y,z});

world->update(timeStep);

Hi Daniel,

In the game simulate area, I want to make the physics world state rollback to 1 second ago(maybe 20 frames).

My solution is to save a queue of WorldState, which contains a list of all PhysicObjectState. The PhysicObjectState contains Transform \ LinearVelocity \ AngularVelocity. When do rollback, I set the Transform \ LinearVelocity \ AngularVelocity back to corresponding physic object.

Is these enough? do I need save more info?