I am making a game in DirectX 8 for a retrocomputing game contest. I am creating a Real Time Strategy game, and I am trying to make a minimap, which is merely an orthographic view of the terrain. When I try to do this, though, I get black pixels:

Here is some of my code:

void TERRAIN::RenderLandscape()
{
    //Set orthogonal rendering view & projection
    SetOrthogonalView();

    //Retrieve the surface of the back buffer
    IDirect3DSurface8 *backSurface = NULL;
    m_pDevice->GetRenderTarget(&backSurface);

    //Get the surface of the minimap texture
    IDirect3DSurface8 *landScapeSurface = NULL;
    m_pLandScape->GetSurfaceLevel(0, &landScapeSurface);

    //Set render target to the m_visible surface
    m_pDevice->SetRenderTarget(landScapeSurface, backSurface);



    //Clear render target to black
    m_pDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x00000000, 1.0f, 0);

    m_pDevice->BeginScene();


    m_pDevice->SetTextureStageState(1, D3DTSS_TEXCOORDINDEX, 0);
    //Set render states     
    m_pDevice->SetRenderState(D3DRS_LIGHTING, false);
    m_pDevice->SetRenderState(D3DRS_ZWRITEENABLE, true);

    //Alpha from alphaTextures, stage 0
    m_pDevice->SetTextureStageState(0, D3DTSS_ALPHAOP, D3DTOP_SELECTARG1);
    m_pDevice->SetTextureStageState(0, D3DTSS_ALPHAARG1, D3DTA_TEXTURE);

    //Color from textures, stage 1
    m_pDevice->SetTextureStageState(1, D3DTSS_COLOROP, D3DTOP_SELECTARG1);
    m_pDevice->SetTextureStageState(1, D3DTSS_COLORARG1, D3DTA_TEXTURE);
    m_pDevice->SetTextureStageState(1, D3DTSS_ALPHAOP, D3DTOP_SELECTARG1);
    m_pDevice->SetTextureStageState(1, D3DTSS_ALPHAARG1, D3DTA_CURRENT);

    //Set blend states
    m_pDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, true);
    m_pDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
    m_pDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);

    m_pDevice->SetMaterial(&m_mtrl);

    //Draw mesh once for each terrain type
    for (int i = 0; i < (int)m_diffuseMaps.size(); i++)
    {
        m_pDevice->SetTexture(0, m_alphaMaps[i]);
        m_pDevice->SetTexture(1, m_diffuseMaps[i]);

        for (int p = 0; p < (int)m_patches.size(); p++)
        {

            m_patches[p]->Render();
        }
    }


    m_pDevice->EndScene();

    
    //Reset render target to back buffer
    m_pDevice->SetRenderTarget(0, backSurface);

    //Release surfaces
    landScapeSurface->Release();
    backSurface->Release();

    D3DXSaveTextureToFile("lscape.bmp", D3DXIFF_BMP, m_pLandScape, NULL);
}

I was able to create what I wanted the minimap to look like by calling the orthographic function that is shown earlier on in the function:

However, I only get a black image. What could I be doing wrong? I have searched around and none of the online help so far or the demos I have found are of any help.

Thanks,

-RJ