Merge pull request #7069 from AndrewMeadows/another-crash-fix

Fix crash when propagating simulation ownership on deleted objects

libraries/physics/src/PhysicalEntitySimulation.cpp

@@ -167,12 +167,13 @@ void PhysicalEntitySimulation::getObjectsToRemoveFromPhysics(VectorOfMotionState
         _entitiesToAddToPhysics.remove(entity);
 
         EntityMotionState* motionState = static_cast<EntityMotionState*>(entity->getPhysicsInfo());
-        assert(motionState);
-        _pendingChanges.remove(motionState);
-        _outgoingChanges.remove(motionState);
-        _physicalObjects.remove(motionState);
-        result.push_back(motionState);
-        _entitiesToRelease.insert(entity);
+        if (motionState) {
+            _pendingChanges.remove(motionState);
+            _outgoingChanges.remove(motionState);
+            _physicalObjects.remove(motionState);
+            result.push_back(motionState);
+            _entitiesToRelease.insert(entity);
+        }
 
         if (entity->isSimulated() && entity->isDead()) {
             _entitiesToDelete.insert(entity);

libraries/physics/src/PhysicsEngine.cpp

@@ -136,23 +136,19 @@ void PhysicsEngine::addObjectToDynamicsWorld(ObjectMotionState* motionState) {
     motionState->clearIncomingDirtyFlags();
 }
 
-// private
-void PhysicsEngine::removeObjectFromDynamicsWorld(ObjectMotionState* object) {
-    // wake up anything touching this object
-    bump(object);
-    removeContacts(object);
-
-    btRigidBody* body = object->getRigidBody();
-    assert(body);
-    _dynamicsWorld->removeRigidBody(body);
-}
-
 void PhysicsEngine::removeObjects(const VectorOfMotionStates& objects) {
+    // first bump and prune contacts for all objects in the list
     for (auto object : objects) {
-        removeObjectFromDynamicsWorld(object);
+        bumpAndPruneContacts(object);
+    }
+
+    // then remove them
+    for (auto object : objects) {
+        btRigidBody* body = object->getRigidBody();
+        assert(body);
+        _dynamicsWorld->removeRigidBody(body);
 
         // NOTE: setRigidBody() modifies body->m_userPointer so we should clear the MotionState's body BEFORE deleting it.
-        btRigidBody* body = object->getRigidBody();
         object->setRigidBody(nullptr);
         body->setMotionState(nullptr);
         delete body;
@@ -163,7 +159,8 @@ void PhysicsEngine::removeObjects(const VectorOfMotionStates& objects) {
 void PhysicsEngine::removeObjects(const SetOfMotionStates& objects) {
     for (auto object : objects) {
         btRigidBody* body = object->getRigidBody();
-        removeObjectFromDynamicsWorld(object);
+        assert(body);
+        _dynamicsWorld->removeRigidBody(body);
 
         // NOTE: setRigidBody() modifies body->m_userPointer so we should clear the MotionState's body BEFORE deleting it.
         object->setRigidBody(nullptr);
@@ -200,7 +197,13 @@ VectorOfMotionStates PhysicsEngine::changeObjects(const VectorOfMotionStates& ob
 }
 
 void PhysicsEngine::reinsertObject(ObjectMotionState* object) {
-    removeObjectFromDynamicsWorld(object);
+    // remove object from DynamicsWorld
+    bumpAndPruneContacts(object);
+    btRigidBody* body = object->getRigidBody();
+    assert(body);
+    _dynamicsWorld->removeRigidBody(body);
+
+    // add it back
     addObjectToDynamicsWorld(object);
 }
 
@@ -402,7 +405,7 @@ void PhysicsEngine::dumpStatsIfNecessary() {
 // CF_DISABLE_VISUALIZE_OBJECT = 32, //disable debug drawing
 // CF_DISABLE_SPU_COLLISION_PROCESSING = 64//disable parallel/SPU processing
 
-void PhysicsEngine::bump(ObjectMotionState* motionState) {
+void PhysicsEngine::bumpAndPruneContacts(ObjectMotionState* motionState) {
     // Find all objects that touch the object corresponding to motionState and flag the other objects
     // for simulation ownership by the local simulation.
 
@@ -434,6 +437,7 @@ void PhysicsEngine::bump(ObjectMotionState* motionState) {
             }
         }
     }
+    removeContacts(motionState);
 }
 
 void PhysicsEngine::setCharacterController(CharacterController* character) {

libraries/physics/src/PhysicsEngine.h

@@ -78,9 +78,6 @@ public:
     /// \return position of simulation origin in domain-frame
     const glm::vec3& getOriginOffset() const { return _originOffset; }
 
-    /// \brief call bump on any objects that touch the object corresponding to motionState
-    void bump(ObjectMotionState* motionState);
-
     void setCharacterController(CharacterController* character);
 
     void dumpNextStats() { _dumpNextStats = true; }
@@ -94,7 +91,9 @@ public:
 
 private:
     void addObjectToDynamicsWorld(ObjectMotionState* motionState);
-    void removeObjectFromDynamicsWorld(ObjectMotionState* motionState);
+
+    /// \brief bump any objects that touch this one, then remove contact info
+    void bumpAndPruneContacts(ObjectMotionState* motionState);
 
     void removeContacts(ObjectMotionState* motionState);