Digital Dustbusting workflow

Hello,
I just attended the virtual NAB seminar introducing Sihlouette paint. Thanks to the Borisfx staff for producing that event. I’m new to the application but have a big film project that was shot on film and the negative was cut. So I have dust-busting work to do. I have a b/w alpha channel that contains the IR dust map and would like to use it as a matte for the paint strokes if this speeds up the process. Watching the seminar it looked like the clone tool or the blemish tool might be useful for dustbusting. I’m looking for documentation on what the preferred workflow / best practices are in Hollywood for this kind of work on features. Can anyone point me in the right direction?
Thanks!

@bnaleid Please refer to the Obey Alpha - Use Input Alpha Tutorial in the User Guide. You are able to use the alpha from a clip as source to limit where you paint. This will make painting out the dust much faster.

Hi @marco
I read the tutorial and it seems pretty simple but I’ll probably run into some issues later. Can you check my initial math: It looks like I have three methods available… 1) I can set the alpha source to embedded using the Source > Foreground setting. 2) I can set an external matte file as the alpha source using the Source > Input 1 3) I can create a painted alpha and select Source > Output.

If this is all correct, then with source footage that has an embedded alpha, I would select Source > Foreground, but then If I need to modify this alpha with new drawn shapes is that possible? You know, a sort of hybrid between options 1 and 3.

Best method would be:

  1. Embed the alpha with the source you want to paint on
  2. Apply the paint plug-in and before opening the Silhouette interface, set Source Alpha to Preserve Alpha
  3. In the plug-in, go to the Roto node and draw a shape. Initially, it will add to the current alpha. Set the shape blend mode to multiply to combine the shape alpha with the source alpha
  4. In the Paint node, select the Clone Brush.
  5. Set the Clone > Source to Foreground.
  6. In the Paint tab, enable Alpha > Obey and set Alpha > Source to Foreground
    You will now paint only in areas of alpha.

Great. Thanks!