Fusion Connect - Change alpha to premultiplied?

I am testing using Fusion to create text (as Resolve Text isn't up to scratch). I want to only bring the text in with an alpha as it makes it much easier/faster to move/retime text. i.e. I do not want to bring the text pre-composited over the background picture as making changes becomes time consuming and tedious.

I can happily get my Fusion Text render back into Resolve with my alpha and it keys over the background picture. Unfortunately the edges aren't great because it wants to be premultiplied. My issue is that I want the composite to be premultiplied but I see no way to adjust this setting on a Fusion Connect clip as the clip attributes option is disabled.

If I manually bring in my Fusion render, and change the alpha mode to premultiply it looks exactly as expected and I am a happy man, but this is a pain for multiple clips due to the way Blackmagic structures the Compositions folder. Plus I would like the Fusion Connect functionality for when my clients want to make changes.

Is this something that needs to be turned into a Feature request or is there a way to achieve what I want that I am not aware of? I can't seem to find a master setting to set all alphas to premultiplied which was the only other option I could think of.

What image type or codec are you rendering-to in Resolve? Have you tried render to TIFF and selecting the include alpha option (don't recall if this is the exact name of the option but it's not the render to color option).

If you cannot change the alpha mode in Resolve, try to put a "Alpha Multiply" node in Fusion before the Saver

What image type or codec are you rendering-to in Resolve? Have you tried render to TIFF and selecting the include alpha option (don't recall if this is the exact name of the option but it's not the render to color option).

Thanks for the suggestion Steve. I'm getting an alpha into Resolve fine using ProRes4444. As I mentioned, if I manually bring it in and set alpha to premultiply then it looks good too. My issue is there is no way to set alpha to premultiply on a Fusion Connect clip, nor a way to set the default handling of alphas to premultiply from what I can see.


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If you cannot change the alpha mode in Resolve, try to put a "Alpha Multiply" node in Fusion before the Saver

Thanks for the suggestion. That sounds like something that could possibly work. I've tried the premultiply option on the Saver node which doesn't seem to make a difference so I'll give alpha multiply a go. If it works I'll be sure to post it.


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Unfortunately, the alpha premultiply seems to have no effect in Resolve.

Looks like for now I either need to comp the title onto picture, or I need to bring in the renders manually and change the clip attributes alpha to premultiply.

Bummer, but not the end of the world. If anyone else has any suggestions then I would love to hear them.

Hi Adam - I created a tutorial that illustrates the use of a TIFF sequence between Resolve and Fusion - see the second half where it illustrates the workflow you described. May not be much use to you but hopefully others on this forum will find the two workflow approaches valuable.

Cheers

Hi Adam - I created a tutorial that illustrates the use of a TIFF sequence between Resolve and Fusion - see the second half where it illustrates the workflow you described. May not be much use to you but hopefully others on this forum will find the two workflow approaches valuable.

Cheers

Hi Steve,

My problem isn't generating the alpha or getting it into Resolve but how Resolve deals with a Fusion Connect clip, limiting the alpha options (I want to select premultiplied but it does not allow this on a Fusion Connect clip).

I totally applaud what you are doing though and thanks for trying to help out.

Thanks Adam - I understood that it wasn't what you were looking for exactly and I agree that it would be cool to be able select how Resolve treats the alpha from Fusion...

The trick for the alpha is to add an alpha divide prior to your saver node. Then it keys nicely in Resolve and you don't have to worry about the premultiply option for alpha in a Fusion Connect clip.