Rendering Cycles and Internal in the same scene without compositing

Question

I have a scene that's 90% Blender Internal (for speed) with 1 object in Cycles (because that one object looks way better in Cycles). My question is is it possible for me to: Set the single blend file rendering Have it output the BI scene and Cycles scene into a single openEXR multilayer file

I was hoping to render everything as quickly as possible and then do a final composite after everything's rendered so I don't waste time compositing frames that might be wrong or broken. So far I've got a 3rd scene that I've been using to composite both scenes at render time so I know how to get that setup going, I'm just hoping someone can tell me how to render both scenes at the same time without having to composite them.

Ideally I'm looking for: Scene 1 = Internal -> Outputs to sequence BI_render_.exr Scene 2 = Cycles -> Outputs to sequence Cycles_render_.exr

If it comes down to it I might be able to do the Cycles render separately because the single object should be quite quick to do on its own but I was thinking this would be practice for a more complex setups for the future.

I have to admit I have a horrible feeling this can't be done but I just have to ask.

Thanks

Answer 1

If you mean without using the compositor at all, then I don't think it can be done in one go, but it should be easy to render one scene and then the other.

If you mean just without combining the Cycles BI renders, then it is possible:

File output node:

This can be done with the File output node.

Setup your 3rd scene's composite nodes like this:

Select the File output node and set the output format to Multilayer EXR. You can add inputs (layers) with the Add input button in the Properties region (N):

So if you wanted you could even put both the BI and cycles renders in one EXR sequence:

When you want to composite you can open the multilayer EXR in an Image node and get all your layers: