对象的访问冲突

>我有一个像这样的Entity.h：

使用命名空间 physx;

class Entity
{
public:
    Entity(Ogre::Vector3 dims, Ogre::Vector3 pos, std::string mesh, std::string id);
    virtual ~Entity(void);
    virtual void update(Ogre::Real dt);
    virtual void init(Ogre::SceneManager* sceneMgr, PxPhysics* physics, PxScene* scene, PxVec3 velocity=PxVec3(0, 0, 0));
protected:
    Ogre::Entity*       mOgreEntity = NULL;
    Ogre::SceneNode*    mOgreNode = NULL;
    Ogre::Vector3       mPosition;
    Ogre::Vector3       mDimensions;
    std::string         mMesh;
    std::string         mId;

    PxRigidDynamic*     mActor;
    PxMaterial*         mMaterial;
};

这是我的实体来源：

#include "Entity.h"
Entity::Entity(Ogre::Vector3 dims, Ogre::Vector3 pos, std::string mesh, std::string id) 
{
    mDimensions = dims;
    mPosition   = pos;
    mMesh       = mesh;
    mId         = id;
    mActor      = NULL;
    mMaterial   = NULL;
}
Entity::~Entity(void)
{
}
void Entity::update(Ogre::Real dt)
{
    PxVec3 pos = mActor->getGlobalPose().p;
    Ogre::Real r = 0;
    mOgreNode->setPosition(Ogre::Vector3(pos.x + r, pos.y + r, pos.z + r));
}
void Entity::init(Ogre::SceneManager* sceneMgr, PxPhysics* physics, PxScene* scene, PxVec3 velocity)
{
    // Create an Entity
    mOgreEntity = sceneMgr->createEntity(mId, mMesh);
    mOgreEntity->setCastShadows(true);
    // Create a SceneNode and attach the Entity to it
    mOgreNode = sceneMgr->getRootSceneNode()->createChildSceneNode(mId + "Node");
    Ogre::AxisAlignedBox box = mOgreEntity->getBoundingBox();
    Ogre::Vector3 realSizes = box.getSize();
    mOgreNode->setPosition(mPosition);
    mOgreNode->attachObject(mOgreEntity);
    Ogre::Vector3 scaler = Ogre::Vector3(mDimensions.x / realSizes.x, mDimensions.y / realSizes.y, mDimensions.z / realSizes.z);
    mOgreNode->scale(scaler);

    mMaterial = physics->createMaterial(1.5f, 1.5f, 1.0f);
    PxGeometry* geometry = NULL;
    if(mMesh == "sphere.mesh")
    {
        PxGeometry g = PxSphereGeometry(mDimensions.x / 2); // Because it's a radius
        geometry = &g;
    } else {
        // geometry = NULL;
    }
    PxTransform transform = PxTransform(PxVec3(mPosition.x, mPosition.y, mPosition.z));
    mActor = PxCreateDynamic(*physics, transform, *geometry, *mMaterial, PxReal(.1));
    // if(!mActor) {
 //        MessageBox( NULL, "no actor", "An exception has occured!", MB_OK | MB_ICONERROR | MB_TASKMODAL);
    //  return;
    // }
    mActor->setLinearVelocity(velocity);
    // And add the actor to a scene:
    scene->addActor(*mActor);
}

现在，如果我创建一个实体并初始化它就可以了。即使有第二个实体变量，它也可以工作。现在有一个数组：

Entity *mEntities[20];
for(int i = 0 ; i < 20 ; i++ ){
    ostringstream nameStream;
    nameStream << "Sphere_" << i;
    string name = nameStream.str();
    Entity* sphere = new Entity(Ogre::Vector3(i*5, i*4.5, i*6), Ogre::Vector3(i*5, i*4.5, i*6), "sphere.mesh", name);
    sphere->init(mSceneMgr, mPhysics, gScene, PxVec3(-10.0f, 0, 0));
    mEntities[i] = sphere;
}

我得到了Access violation.使用实时调试器，事实证明mActor为空且mMaterial

编辑：

此代码也不起作用：

    mEntity = Entity(Ogre::Vector3(50.0f, 50.0f, 50.0f), Ogre::Vector3(50.0f, 40.5f, 60.0f), "sphere.mesh", "sphere");
    mEntity.init(mSceneMgr, mPhysics, gScene, PxVec3(-10.0f, 0, 0));