3D and 2D display in DirectX - directx

Question

I want to render some sprites over my 3D scene, but when I enable D3D sprites, my 3D scene dissapears and i can see only those sprites.
Settings:
LPDIRECT3D9 d3d = NULL;
LPDIRECT3DDEVICE9 d3ddev = NULL;
D3DPRESENT_PARAMETERS d3dpp;
LPD3DXSPRITE d3dspt;
// Create Direct3D and the Direct3D Device
void InitDirect3D(GAMEWINDOW* gw)
{
d3d = Direct3DCreate9(D3D_SDK_VERSION);
ZeroMemory(&d3dpp, sizeof(d3dpp));
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;
d3dpp.Windowed = gw->Windowed;
d3dpp.BackBufferWidth = gw->Width;
d3dpp.BackBufferHeight = gw->Height;
d3dpp.EnableAutoDepthStencil = TRUE;
d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
d3d->CreateDevice(D3DADAPTER_DEFAULT,
D3DDEVTYPE_HAL,
gw->hWnd,
D3DCREATE_SOFTWARE_VERTEXPROCESSING,
&d3dpp,
&d3ddev);
d3ddev->SetRenderState(D3DRS_LIGHTING, FALSE);
d3ddev->SetRenderState(D3DRS_ZENABLE, TRUE);
d3ddev->SetRenderState(D3DRS_CULLMODE, TRUE);
D3DXCreateSprite(d3ddev, &d3dspt);
return;
}
Rendering:
// Start rendering
void StartRender()
{
d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
d3ddev->Clear(0, NULL, D3DCLEAR_ZBUFFER, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
d3ddev->BeginScene();
d3dspt->Begin(D3DXSPRITE_ALPHABLEND); // when enabled, 3d scene dissapears
return;
}
// Stop rendering
void EndRender()
{
d3dspt->End(); // disabling sprites
d3ddev->EndScene();
d3ddev->Present(NULL, NULL, NULL, NULL);
return;
}
Rendering function:
void Render()
{
static int frame = 0;
if (frame == 36) frame = 0;
StartRender();
DrawSprite(&interceptor, frame++, 100, 100, 0);
DrawModel(&a, 0.0f, 0.0f, 0.0f);
EndRender();
return;
}

Answer 1

Try processing your sprites separately from the rest of your scene. You could create a single render function that would make your life much easier:
void Render()
{
d3ddev->Clear(0, NULL, D3DCLEAR_TARGET|D3DCLEAR_ZBUFFER,
D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
d3ddev->BeginScene();
d3dspt->Begin(D3DXSPRITE_ALPHABLEND);
My3DRenderingFunction();
MySpriteRenderingFunction();
d3dspt->End(); // disabling sprites
d3ddev->EndScene();
d3ddev->Present(NULL, NULL, NULL, NULL);
}
The My3DRenderingRunction() and MySpriteRenderingFunction() would be your custom functions where you would render everything. You could even pass a callback function (function pointer) to the render function. Also, note how you don't need two Clear() calls. You can just use one:
d3ddev->Clear(0, NULL, D3DCLEAR_TARGET|D3DCLEAR_ZBUFFER,
D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);