I have a problem with a simple game I am writing. I have a simple rectangular room - with 4 walls, floor and ceiling. I have mapped a texture to the walls and another to the floor+ceiling. When I move the camera position left/right, the left/right walls appear to jump, as the camera moves. I know that the model is ok, as this only happens when texture mapping is used. Any suggestions would be much appreciated.

It only happens when the textures are used. Without textures the mesh works without jumping.

Here is the code which initialises the room objects:
D3DXCreateTextureFromFile( m_pd3dDevice, "data\\water1.bmp",
&m_pTextureWalls );
D3DXCreateTextureFromFile( m_pd3dDevice, "data\\rock2.bmp",
&m_pTextureWalls2 );

if( FAILED( m_pd3dDevice->CreateVertexBuffer( WALL_VERT_NUM * sizeof(WALLVERTEX),
0, D3DFVF_WALLVERTEX, D3DPOOL_MANAGED, &m_pVBWalls, NULL ) ) )
{
return E_FAIL;
}

WALLVERTEX* pVertices;
m_pVBWalls->Lock( 0, 0, (void**)&pVertices, 0 );

FILL_WALLVERTEX( pVertices[ 0], -5.0f,-5.0f, 5.0f, 0.00f, 1.0f );
FILL_WALLVERTEX( pVertices[ 1], -5.0f, 5.0f, 5.0f, 0.00f, 0.0f );
FILL_WALLVERTEX( pVertices[ 2], 5.0f,-5.0f, 5.0f, 1.00f, 1.0f );
FILL_WALLVERTEX( pVertices[ 3], 5.0f, 5.0f, 5.0f, 1.00f, 0.0f );
FILL_WALLVERTEX( pVertices[ 4], 5.0f,-5.0f,-5.0f, 0.00f, 1.0f );
FILL_WALLVERTEX( pVertices[ 5], 5.0f, 5.0f,-5.0f, 0.00f, 0.0f );
FILL_WALLVERTEX( pVertices[ 6], -5.0f,-5.0f,-5.0f, 1.00f, 1.0f );
FILL_WALLVERTEX( pVertices[ 7], -5.0f, 5.0f,-5.0f, 1.00f, 0.0f );
FILL_WALLVERTEX( pVertices[ 8], -5.0f,-5.0f, 5.0f, 0.00f, 1.0f );
FILL_WALLVERTEX( pVertices[ 9], -5.0f, 5.0f, 5.0f, 0.00f, 0.0f );

m_pVBWalls->Unlock();

// Create the floor/ceiling vertex buffer
if( FAILED( m_pd3dDevice->CreateVertexBuffer( FLOORCEILING_VERT_NUM * sizeof(FLOORCEILINGVERTEX),
0, D3DFVF_FLOORCEILINGVERTEX, D3DPOOL_MANAGED, &m_pVBFloorCeiling, NULL ) ) )
{
return E_FAIL;
}

FLOORCEILINGVERTEX* pFloorVertices;
m_pVBFloorCeiling->Lock( 0, 0, (void**)&pFloorVertices, 0 );
FILL_FLOORCEILINGVERTEX( pFloorVertices[0], -5,-5, 5, 0, 1, 0, 0.0f, 0.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[1], 5,-5, 5, 0, 1, 0, 0.0f, 1.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[2], 5,-5,-5, 0, 1, 0, 1.0f, 1.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[3], 5,-5,-5, 0, 1, 0, 1.0f, 1.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[4], -5,-5,-5, 0, 1, 0, 1.0f, 0.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[5], -5,-5, 5, 0, 1, 0, 0.0f, 0.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[6], 5, 5,-5, 0,-1, 0, 1.0f, 1.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[7], 5, 5, 5, 0,-1, 0, 0.0f, 1.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[8], -5, 5, 5, 0,-1, 0, 0.0f, 0.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[9], -5, 5, 5, 0,-1, 0, 0.0f, 0.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[10], -5, 5,-5, 0,-1, 0, 1.0f, 0.0f );
FILL_FLOORCEILINGVERTEX( pFloorVertices[11], 5, 5,-5, 0,-1, 0, 1.0f, 1.0f );
m_pVBFloorCeiling->Unlock();

And this is the rendering code:

void Walls::setTransfPipe()
{
D3DXMATRIXA16 matWorld, matScale;

D3DXMatrixTranslation( &matWorld, 0.0f, 0.0f, 250.0f);
D3DXMatrixScaling(&matScale, 10.0f, 4.0f, 50.0f);

D3DXMatrixMultiply(&matWorld, &matScale, &matWorld);
m_pd3dDevice->SetTransform( D3DTS_WORLD, &matWorld );

}
void Walls::setMaterials()
{
// Set / update surface material properties. P
D3DMATERIAL9 mtrl;
ZeroMemory( &mtrl, sizeof(D3DMATERIAL9) );
mtrl.Diffuse.r = mtrl.Ambient.r = 0.8f;
mtrl.Diffuse.g = mtrl.Ambient.g = 0.8f;
mtrl.Diffuse.b = mtrl.Ambient.b = 0.8f;

m_pd3dDevice->SetMaterial( &mtrl ); // Only one material can be used at a time.
}
void Walls::Render()
{
setTransfPipe();

setMaterials();

// Render Floor & Ceiling

m_pd3dDevice->SetTexture( 0, m_pTextureWalls );

m_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLOROP, D3DTOP_SELECTARG1 );
m_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLORARG1, D3DTA_TEXTURE );

m_pd3dDevice->SetFVF( D3DFVF_FLOORCEILINGVERTEX );
m_pd3dDevice->SetStreamSource( 0, m_pVBFloorCeiling, 0, sizeof(FLOORCEILINGVERTEX) );
m_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLELIST, 0, 4 );

// Render the multi-textured object
m_pd3dDevice->SetTexture( 0, m_pTextureWalls2 );

m_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLOROP, D3DTOP_SELECTARG1 );
m_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLORARG1, D3DTA_TEXTURE );

m_pd3dDevice->SetFVF( D3DFVF_WALLVERTEX );
m_pd3dDevice->SetStreamSource( 0, m_pVBWalls, 0, sizeof(WALLVERTEX) );
m_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLESTRIP, 0, 8);
m_pd3dDevice->SetTexture( 0, NULL );
}

I am using LPDIRECT3DVERTEXBUFFER9 objects, rather than D3DXMESH objects.

Thanks for your help anyway. As this is just for a uni assignment, i''ll not worry too much right now. Although I would like to know the reason for the problem, to help in future developments... I''m thinking that it may be a scaling issue.

As my room starts as a square, and is being scaled into a rectanglar shape. Would this have an effect on the texturing? I understand the basic theory behind texture mapping, but i''m not so certain as to how it is implemented.