Contents

Preface
3D File Formats
The Framework
X File Class
Down to the Code

Source code
Printable version

The Series

The Basics
First Steps to
Animation
Multitexturing
Building Worlds
With X Files

Down to the Code

You know most of the code from the second tutorial First Steps to Animation, so we can concentrate on the new X file code.

OneTimeSceneInit()

Loading an object should happen in the OneTimeSceneInit() method of your main file:


HRESULT CMyD3DApplication::OneTimeSceneInit()
{
  // yellow object
  m_pObjects[0].vLoc   = D3DVECTOR(-1.0f, 0.0f, 0.0f);
  m_pObjects[0].fYaw   = 0.0f;
  m_pObjects[0].fPitch = 0.0f;
  m_pObjects[0].fRoll  = 0.0f;

  // red object
  m_pObjects[1].vLoc   = D3DVECTOR(1.0f, 0.0f, 0.0f);
  m_pObjects[1].fYaw   = 0.0f;
  m_pObjects[1].fPitch = 0.0f;
  m_pObjects[1].fRoll  = 0.0f;

  HRESULT hr;

  // yellow object
  m_pObjects[0].m_pFile  = new CD3DFile();
    
  hr = m_pObjects[0].m_pFile->Load ("boidy2.x");

  if( FAILED(hr) )
  {
    MessageBox( NULL, TEXT("Error loading boidy.x file"),
                TEXT("Animation"), MB_OK|MB_ICONERROR);
    return E_FAIL;
  }
    
  // get the X file matrix
  CD3DFileObject* pObject =
    m_pObjects[0].m_pFile->FindObject( "BOID_Root" );

  if( pObject )
  {
    m_pObjects[0].matLocal = *pObject->GetMatrix();
  }

  // red object
  // the same as above

  return S_OK;
}

After allocating the X file class, we could load the X file and search for the BOID_Root Frame template and later for the FrameTransformMatrix template to get the transformation matrix. That's easy ... isn't it? To store the class pointer in the structure of the object, I've expanded the structure used by the objects like this:


struct Object
{
  CD3DFile*   m_pFile;
  D3DVECTOR   vLoc;
  FLOAT       fYaw, fPitch, fRoll; 
  D3DMATRIX   matLocal;
};

You'll find it at the beginning of the objects.cpp file.

Render()

To render the X files, a simple call to CD3DFile::Render() has to be performed:


...
if (m_pObjects[0].m_pFile)
  m_pObjects[0].m_pFile->Render( m_pd3dDevice );

// Apply the object's local matrix
m_pd3dDevice->SetTransform(D3DTRANSFORMSTATE_WORLD,
                           &m_pObjects[0].matLocal);
...

Ok, that wasn't difficult.

Finale

Rumours tell us that the X file support in DirectX 8 will be greatly enhanced. There should be a Maya and a 3D Studio Max X file exporter with source. New X file handling routines will be provided with Direct3D's utility library, Direct3DX. So your time has been well-spent learning the ins and outs of the X file format and the simple interface provided by the Direct3D 7 Framework.

I hope you enjoyed our trip to the X file format. This will be a work in progress in the future. If you find any mistakes or if you have any good ideas to improve this tutorial or if you dislike or like it, give me a sign at wolf@direct3d.net.