Kamera bewegung funktionert nicht

[c++lernerbrauch hilfe]

Ich versuche gerade die Kamera zu bewegen, leider bewegt sie sich aber NICHT

.......
		if(bKey[DIK_W])
		{
			TransZ = TransZ + 0.5f;
		}

}

void Render_Rennen()
{

	lp3DDevice->Clear(0,NULL,D3DCLEAR_TARGET,D3DCOLOR_XRGB(0,0,0),1.0f,0);
	lp3DDevice->Clear(0,NULL,D3DCLEAR_ZBUFFER,D3DCOLOR_XRGB(0,0,0),1.0f,0);
	lp3DDevice->BeginScene();
    D3DXMATRIX matrix;
    D3DXMATRIX ViewMatrix;

    D3DXMatrixLookAtLH(&ViewMatrix,
                       &D3DXVECTOR3( 0.0f,  0.0f,-10.0f ),
                       &D3DXVECTOR3( 0.0f,  0.0f, 0.0f ),
                       &D3DXVECTOR3( 0.0f,  1.0f, 0.0f ));

	D3DXMatrixTranslation(&matrix,0.0f,0.0f,TransZ);
         D3DXMatrixMultiply(&ViewMatrix,&ViewMatrix,&matrix);
	lp3DDevice->SetTransform(D3DTS_VIEW,&ViewMatrix);
	lp3DDevice->SetStreamSource(0,Road,0,sizeof(CustomVertex));
	lp3DDevice->SetTexture(0,lpTexture5);
	lp3DDevice->DrawPrimitive(D3DPT_TRIANGLELIST,0,2);
	lp3DDevice->EndScene();
	lp3DDevice->Present(NULL,NULL,NULL,NULL);
}