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Render Passes + Alpha

PostPosted: Thu Jul 30, 2020 10:32 am
by stevepickup
Hello - New user of Octane and really like it.
Hope you'll excuse the potentially stupid question.

Firstly, is it possible to render an object but still have it contribute to the alpha channel? So, you can then select this later in post and change stuff.

From what I’ve been reading I suspect not, and actually the way to do this is using the ‘object layer ID’ – instead give object A one ID and object B a second ID. Then in the ROP tick ‘render object layers’ and layers to render 1-2, layers mode normal. And render to disk.

However for the life of me I can’t seem to get Octane to save out the two layered files (format is Multilayer EXR Untonemapped - $HIP/render/$HIPNAME.$OS.$F4) If I tick ‘Render to MPlay’ I can see the two layers render, but it only ever save the final layer rendered.?? Im guessing im missing something very simple an obvious but sorry cant seem to figure it out.

Also im guessing the Layer render option for this is going to be slower because is has to render the scene twice or more to get the layers - is there actually a more efficient way to do this?

Answers to any of the above would be a massive help - thanks

Re: Render Passes + Alpha

PostPosted: Tue Aug 04, 2020 8:08 am
by juanjgon
Hi,

To save the render layers you need to add to the filename the $OCTANE_LAYER tag to let the plugin add the layer ID to the file name. For example: $HIP/render/$HIPNAME.$OS.$OCTANE_LAYER.$F4

https://docs.otoy.com/HoudiniH/HoudiniP ... gsOutp.htm

Thanks,
-Juanjo

Re: Render Passes + Alpha

PostPosted: Thu Aug 06, 2020 1:31 pm
by stevepickup
Oh thank you! worked a treat
I think i must have been adding in the $OCTANE_LAYER in the wrong order