   Splitting RGB and A
  Hi,I would like to know it it is possible in directX to split and render to different devices.Can I render a scene to an adapter/multihead monitor and its alpha to another display adapter multihead screen.ThanksMaxbuzz  
  If the NumberOfAdaptersInGroup cap is greater than 1, (i.e. the card and driver exposes its multihead to DirectX 9), then yes. When you create the device as multihead (D3DCREATE_ADAPTERGROUP_DEVICE), each head is then just a different swap chain.So you just do:SetRenderTarget( swapchain1_backbuffer )Set states for colour rendering onlyRender()SetRenderTarget( swapchain2_backbuffer )Set states to display the alpha channel as a colourRender()Present()If the device and/or driver doesn''t expose that cap or the multimonitor setup is across separate cards you''ll have to do it the hard and inefficient way and create two independent devices and duplicate all resources.Alternatively you could do all rendering twice on the faster of the devices and manually copy the all the alpha data over to the other device (Lock->Copy->Unlock). I believe something similar happens with windowed mode D3D when the output window straddles both monitors - only one device actually does the render and the overlap is copied and clipped using the CPU.   --Simon O''Connorex  -Creative AsylumProgrammer &Microsoft MVP