Hello everyone, i get a problem about render to texture.The problem is that i set the D3DXMatrixOrthoLH. hope render from (0,0) to (width,height), and i set the render target dimension as (a*width, a*height). Hope it will render the scene from (0,0,z) to (width,height,z) to a texture with dimension (a*width, a*height). But the texture doesn't just full fill the scene. below is some code:

//imaging this is the render result

|<-(a*width)->|

---------------
|        |    |  
|        |    |  a*height
|        |    |
|---------    |
|             |
---------------

the result only render in the small square, not just the a*width and a*height;

//view
D3DXVECTOR3 vecEye(width/2.0f, height/2.0f, 0.0);
D3DXVECTOR3 vecLookAt(width/2.0f, height/2.0f, 1.0);
D3DXVECTOR3 vecUp(0.0f, 1.0f, 0.0f);
D3DXMatrixLookAtLH(&matView,&vecEye,&vecLookAt,&vecUp);

//prjection
D3DXMatrixOrthoLH(&matOrth, width, height, 0, 100);
pD3DDevice->SetTransform(D3DTS_WORLD, &matWorld);
pD3DDevice->SetTransform(D3DTS_VIEW, &matView);
pD3DDevice->SetTransform(D3DTS_PROJECTION, &matOrth);

//create the render target
pD3DDevice->CreateTexture(width*a,height*a,1,D3DUSAGE_RENDERTARGET, D3DFMT_X8R8G8B8, D3DPOOL_DEFAULT, &pD3DTexture, NULL);

pD3DTexture->GetSurfaceLevel(0, &pTextureSurface);

pD3DDevice->SetRenderTarget(0, pTextureSurface);

//render the scene
........

//save the texture data
.............

allien.

Very thank to your help.
it's seem the viewport problem. but when call setviewport without any error. it didn't work. my texture always be clipped acoording to the current viewport (orgVP). (i have try to call setviewport before and after the settransform func, but it's the same). Now, the result only is correct when the dimension of the current viewport is large than (a*width, a*height).


D3DVIEWPORT9 orgVp;
D3DVIEWPORT9 newVp;
newVp.MinZ = 0.0f;
newVp.MaxZ = 1.0f;
newVp.X = 0;
newVp.Y = 0;
newVp.Width = width*a;
newVp.Height = height*a;

pD3DDevice->GetViewport(&orgVp);
hresult = pD3DDevice->SetViewport(&newVp);

//set transform and render to target
....



allien.