/*      NOTE: I am assuming the following:        1) that your rotation angles are stored in:              xAngle, yAngle, zAngle        2) that your positions are stored in:              xPos, yPos, zPos        3) that your scales are in:              xScale, yScale, zScale        4) WNDWIDTH is a macro defined to be the width of your window           WNDHEIGHT is a macro defined to be the height of your window        5) g_pD3DDevice is the name of your initialized            IDirect3DDevice9 object    */    /* code already here such as defining the vertices       creating a vertex buffer, and initializing the above        values if they are not already initialized */    // declare the matrices needed for calculation    D3DXMATRIX matWorld;                   // our world trans matrix    D3DXMATRIX matView;                    // our view matrix    D3DXMATRIX matProj;                    // our projection matrix    D3DXMATRIX matRotX, matRotY, matRotZ;  // the rotation matrices    D3DXMATRIX matTrans;                   // the transformation matrix    D3DXMATRIX matScale;                   // the scale matrix    /* World Transformation Matrix */    // create the rotation matrices    D3DXMatrixRotationX( &matRotX, xAngle );    D3DXMatrixRotationY( &matRotY, yAngle );    D3DXMatrixRotationZ( &matRotZ, zAngle );    // create the translation matrix    D3DXMatrixTranslation( &matTrans, xPos, yPos, zPos );    // create the scale matrix    D3DXMatrixScaling( &matScale, xScale, yScale, zScale );    // start the world matrix as identity, always do this!    D3DXMatrixIdentity( &matWorld );    // combine all of the matrices into the world trans matrix    // note that the order we do this is unique to the world     // transformation and must be kept this way    D3DXMatrixMultiply( &matWorld, &matWorld, &matScale );    D3DXMatrixMultiply( &matWorld, &matWorld, &matRotX );    D3DXMatrixMultiply( &matWorld, &matWorld, &matRotY );    D3DXMatrixMultiply( &matWorld, &matWorld, &matRotZ );    D3DXMatrixMultiply( &matWorld, &matWorld, &matTrans );        /* View Transformation Matrix */    // create the rotation matricies, note that we use opposite     // values here from    what the viewpoint is really at    D3DXMatrixRotationX( &matRotX, -xAngle );    D3DXMatrixRotationY( &matRotY, -yAngle );    D3DXMatrixRotationZ( &matRotZ, -zAngle );    // Create the translation matrix, note the opposite values    D3DXMatrixTranslation( &matTrans, -xPos, -yPos, -zPos );    // start the view matrix as identity, always do this!    D3DXMatrixIdentity( &matView );        // combine all to create the view matrix, note the order     // of combination is unique and must be done this way    D3DXMatrixMultiply( &matView, &matView, &matTrans );    D3DXMatrixMultiply( &matView, &matView, &matRotZ );    D3DXMatrixMultiply( &matView, &matView, &matRotY );    D3DXMatrixMultiply( &matView, &matView, &matRotX );    /* Projection Transformation Matrix */    // find the aspect to use by dividing the window width    // by the window height    float aspect = (float)WNDWIDTH / (float)WNDHEIGHT;    // create the projection transformation matrix    // with help from the d3dx9 library function    D3DXMatrixPerspectiveFovLH( &matProj,    // the projection matrix                                D3DX_PI/4,   // the view range in radians                                aspect,      // aspect of the screen ratio                                1.0f,        // the near clip plane                                1000.0f );   // the far clip plane    /* Attaching the new transformations to Direct3D */    // set the world transform    if( FAILED(g_pD3DDevice->SetTransform( D3DTS_WORLD, &matWorld ))){        // error occurred world trans matrix not set    }    // set the view transform    if( FAILED(g_pD3DDevice->SetTransform( D3DTS_VIEW, &matView ))){        // error occurred view trans matrix not set    }    // set the projection transform    if( FAILED(g_pD3DDevice->SetTransform( D3DTS_PROJECTION, &matProj ))){        // error occurred proj trans matrix not set    }        /* more code here such as clearing the backbuffer       and beginning the scene */    // END OF SOURCE[/SOURCE]