Access Violation when writing to pointer variables in dynamically allocated classes

Ok so the title doesn't explain my situation very well so I'll try to explain a little better here:

Here is part of my class structure:

ObjectView (abstract class)

ShipView : ObjectView (child of object view)

In a method I create a new ShipView:

ShipView *shipview (in header file).

shipview = new ShipView(in main part of code).

I then run shipview->Initialise()开发者_StackOverflow; to set everything up in the new class.

But when I get to any lines of code that try to write to a pointer declared in the ObjectView class it won't allow me to do so and gives me an Access Violation message. The message that I get is below:

"Unhandled exception at 0x00a0cf1c in AsteroidGame.exe: 0xC0000005: Access violation writing location 0xbaadf011."

For example this line:

_ObjectData = new Model[mesh->mNumVertices];

will give me the error.

Just fyi I have put this in the header file:

struct Model{
    GLfloat x,y,z;
    GLfloat nX,nY,nZ;
    GLfloat u,v;
};

Model *_ObjectData;

However if I was to do something along the lines of

Model *_ObjectData = new Model[mesh->mNumVertices];

(declare and initialise all at once)

it would work....

It's like it doesn't know the header file is there, or the class has not been properly constructed therefore the memory has not been allocated properly.

Any help would be greatly appreciated.

EDIT Header File:

class ObjectView
{
public:
    ObjectView(void);
    virtual ~ObjectView(void);

    void Initialise(std::string objectpath, std::string texturepath);
    void InitialiseVBO(const aiScene* sc);  

    void RenderObject();

    virtual void ScaleObject() = 0;
    virtual void TranslateObject() = 0;
    virtual void RotateObject() = 0;

protected:
    struct Model{
        GLfloat x,y,z;
        GLfloat nX,nY,nZ;
        GLfloat u,v;
    };
    Model *_ObjectData;

    struct Indices{
        GLuint x,y,z;
    };
    Indices *_IndicesData;  

    TextureLoader _textureloader;
    GLuint _objectTexture;

    GLuint _objectVBO;
    GLuint _indicesVBO;

    int _numOfIndices;
};

Code:

void ObjectView::InitialiseVBO(const aiScene* sc)
{   
    const aiMesh* mesh = sc->mMeshes[0];

    _ObjectData = new Model[mesh->mNumVertices];

    for(unsigned int i = 0; i < mesh->mNumVertices; i++)
    {
        _ObjectData[i].x = mesh->mVertices[i].x;
        _ObjectData[i].y = mesh->mVertices[i].y;
        _ObjectData[i].z = mesh->mVertices[i].z;

        _ObjectData[i].nX = mesh->mNormals[i].x;
        _ObjectData[i].nY = mesh->mNormals[i].y;
        _ObjectData[i].nZ = mesh->mNormals[i].z;

        _ObjectData[i].u = mesh->mTextureCoords[0][i].x;
        _ObjectData[i].v = 1-mesh->mTextureCoords[0][i].y;
    }

    glGenBuffers(1, &_objectVBO);

    glBindBuffer(GL_ARRAY_BUFFER, _objectVBO);
        glBufferData(GL_ARRAY_BUFFER, sizeof(Model) * mesh->mNumVertices, &_ObjectData[0].x, GL_STATIC_DRAW);

    _IndicesData = new Indices[mesh->mNumFaces];

    for(unsigned int i = 0; i < mesh->mNumFaces; ++i)
    {
        for (unsigned int a = 0; a < 3; ++a)
        {
            unsigned int temp = mesh->mFaces[i].mIndices[a];
            if(a == 0)
                _IndicesData[i].x = temp;
            else if(a == 1)
                _IndicesData[i].y = temp;
            else
                _IndicesData[i].z = temp;
        }
    }

    glGenBuffers(1, &_indicesVBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _indicesVBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices) * mesh->mNumFaces, _IndicesData, GL_STATIC_DRAW);

    _numOfIndices = sizeof(Indices) * mesh->mNumFaces;

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    delete _ObjectData;
    delete _IndicesData;
}

If

_ObjectData = new Model[mesh->mNumVertices];

crashes while

Model *_ObjectData = new Model[mesh->mNumVertices];

doesn't, it certainly looks like your object hasn't been initialized.
My psychic debugger suggests that you have declared a different variable, also called shipview, which is what you're calling Initialize() on.

0xbaadf011 is probably an offset from 0xbaadf00d which is a hexadecimal synonym for Bad Food. It is certainly an uninitialized pointer.

You are obviously not setting your pointers before using them. I suggest looking at the call stack when it crashes, set a breakpoint at one of the functions above your crash, then restart the program and run it line by line until you find the pointer that is set to 0xbaadf011 or 0xbaadf00d. Then figure out where you were supposed to set that pointer.