BCC OFX on a Resolve Timeline


#1

Hi all
I have a graphic with an alpha sitting on V2 of a Resolve timeline.
When I drop a BCC OFX plugin on the graphic the Alpha doesn’t change.
I can see the effect affecting the graphic but not the background on V1.
Shouldn’t this work like Media Composser? What am I missing?

BCC 11.0.3 - Resolve 15.2

Cheers. Tim.


#2

Hi Tim,

The result that you are seeing is normal actually. Alpha handling in Avid is a unique situation and required a lot of engineering to work around, the result being that the user needs to tell the filter whether or not it is being used on a clip with an alpha matte and whether other filters are also being used in a stack on the same clip.

Thanks,
Peter.


#3

Thanks for getting back to me Peter.
In Resolve there appears to be no button to change this behaviour.
Is the only way to put a drop shadow or glow on something with an alpha via Fusion?

Tim


#4

Resolve as a host has very clunky alpha support, but you can make it work. Note this NOT unique to Continuum - it is true for all plugins running in Resolve. Also note that Continuum 2019 has improvements which work around Resolve 15 host changes in a couple filters, but overall Continuum 11.0.3 should work ok with alpha in Resolve if you jump through the Resolve hoops. First note that Resolve as a host does NOT respect any changes to alpha channels for filters applied in Edit mode. So if you want to have an effect that modifies an alpha channel you need to work in the Color panel. There is some brief information on alpha in Resolve in the Continuum help docs here, although I can see that more details should be added:

https://borisfx.com/documentation/continuum/bcc-overview-in-resolve/

The workflow is slightly different if you apply the effect directly onto the source node (as described in the above step) or if you apply it as a separate serial node. I’ll update the documentation and send along additional info tomorrow but this may get you started. Doing some general internet research about working with Alpha in Resolve might also be useful for you.

Cheers,
Jason


#5

Sorry for the delay. Here are some updated notes from the Continuum help docs section regarding Resolve.

Working with alpha channels in Resolve requires specific workflow techniques. Note that Resolve currently does not allow an OFX effect to modify the alpha channel unless it is applied in the Color page. If you apply an effect that modifies alpha in the Edit page, then Resolve will simply ignore any alpha changes. Note that even in the Color page you cannot currently apply effects to Resolve native Titles, so if you want to apply an effect to text you should generate the text using Title Studio or to an imported still image with embedded alpha
channel. Please consult Resolve documentation for complete guidance, but to quickly get up and running with BCC effects that create or modify alpha channels in Resolve you can do one of the following depending on whether you apply the effect directly to the main node or to a serial node.

Applying directly to the main node:

  • Drag the effect directly onto the source node
  • Right Click in an empty background area of the node graph and select Add Alpha Output
  • Connect the alpha output from the source node to the main alpha output you just created in the previous step.
  • Right click on the effect node and select Use OFX Alpha
  • Optional - if the node to which the effect is applied already had an external alpha channel such as when applied to still image with embedded alpha, then you may need to re-impose that source alpha channel by right clicking on the source node and selecting Add Matte to restore the matte.

Applying as a serial node:

  • Drag the effect onto the graph to add it as a new serial node.
  • Right Click in an empty background area of the node graph and select Add Alpha Output
  • Connect the alpha output from the effect node to the main alpha output you just created in the previous step.
  • Optional - if the upstream nodes already have an alpha channel, be sure to pipe the alpha channel into the effect node’s alpha.
  • Optional - if the source node has an external alpha channel such as a still image with embedded alpha, then you may need to re-impose that source alpha channel by right clicking on the source node and selecting Add Matte to restore the matte.

#6

Thanks Jason.

This is a big help.

Tim

Tim Hitchen

Hitchen Pictures P/L

e | tim@hitchenpictures.com.au

m | 0418 275 269