From green screen to black and white PNG sequences

Hi,
I was wondering what the best workflow is for pulling a key on green screen footage, and then rendering out black and white PNG sequences of the mattes so that another compositor can use them.

I'm still new to Fusion, so i thought it would be best to ask.

Thanks in advance.

That kind of depends on how much the next compositor can still adjust afterwards.
Why is this something you'd like to do?
Because apart from the key, there is the despilling/edge handling that is usually done best inside a single package.

But if you want to go this route, pull the key, use a channel boolean to copy the alpha channel to your RGB channels and then save those. This will give you a visual reference of the alpha you're saving.
If you don't want to do this, you can just check the 'save alpha to color' checkbox in the export section of your Saver in which case the saver will handle the whole alpha-to-RGB thing.

The shots are locked off and the actors are pretty far away from the green screen, except in a few shots where their feet meet a green screen floor. In that case, I'll use roto to work around it.

The composites are going to be quite simple based on the samples I've been shown. Many of them will just be in front of black backgrounds or black and white photos. Not too complex, thankfully.

How do I generate a black and white render with the mattes from the green screen? Is there some way I can apply the matte to a white background to generate a white over black shot?

Please read the answer from sander again.
He already suggest that you use the channel boolean to Copy the alpha to rgb

Otherwise you can plug you matte into the mask input of a background node

In your keying node, you have the option to look at the matte - keep this option selected and you're ready to render...

Code: Select all

{
   Tools = ordered() {
      Background2 = Background {
         Inputs = {
            Width = Input { Value = 1920, },
            Height = Input { Value = 1080, },
            ["Gamut.SLogVersion"] = Input { Value = FuID { "SLog2" }, },
            TopLeftGreen = Input { Value = 1, },
         },
         ViewInfo = OperatorInfo { Pos = { 55, 49.5 } },
      },
      Merge1 = Merge {
         Inputs = {
            Background = Input {
               SourceOp = "Background2",
               Source = "Output",
            },
            Foreground = Input {
               SourceOp = "Background1",
               Source = "Output",
            },
            PerformDepthMerge = Input { Value = 0, },
         },
         ViewInfo = OperatorInfo { Pos = { 165, 49.5 } },
      },
      Background1 = Background {
         Inputs = {
            Width = Input { Value = 1920, },
            Height = Input { Value = 1080, },
            ["Gamut.SLogVersion"] = Input { Value = FuID { "SLog2" }, },
            EffectMask = Input {
               SourceOp = "Rectangle1",
               Source = "Mask",
            }
         },
         ViewInfo = OperatorInfo { Pos = { 55, 16.5 } },
      },
      Rectangle1 = RectangleMask {
         Inputs = {
            MaskWidth = Input { Value = 1920, },
            MaskHeight = Input { Value = 1080, },
            PixelAspect = Input { Value = { 1, 1 }, },
            ClippingMode = Input { Value = FuID { "None" }, },
         },
         ViewInfo = OperatorInfo { Pos = { 55, -16.5 } },
      },
      DeltaKeyer1 = DeltaKeyer {
         CtrlWZoom = false,
         Inputs = {
            ViewMode = Input { Value = FuID { "Matte" }, },
            BackgroundRed = Input { Value = 0, },
            BackgroundGreen = Input { Value = 1, },
            BackgroundBlue = Input { Value = 0, },
            TuningRanges = Input {
               Value = ColorCurves {
                  Curves = {
                     {
                        Points = {
                           { 0, 1 },
                           { 0.4, 0.2 },
                           { 0.6, 0 },
                           { 1, 0 }
                        }
                     },
                     {
                        Points = {
                           { 0, 0 },
                           { 0.4, 0 },
                           { 0.6, 0.2 },
                           { 1, 1 }
                        }
                     }
                  }
               },
            },
            Input = Input {
               SourceOp = "Merge1",
               Source = "Output",
            },
         },
         ViewInfo = OperatorInfo { Pos = { 275, 49.5 } },
      }
   }
}

Thanks, Frank, and everyone.

Another problem. My Fusion dongle has stopped working.

Please read the answer from sander again.
He already suggest that you use the channel boolean to Copy the alpha to rgb

Otherwise you can plug you matte into the mask input of a background node

Thanks, Michael. I'll see if I can get it to work in Fusion in Resolve 15, since my Fusion dongle is on the fritz at the moment.