roto renderer v1.4

This node allows you dynamically create an unlimited number of roto layers.
Store multiple rotos in a single RGBA file and shuffle them into separate layers

- The rotos stored in each layer can be extracted using a shuffle node.

- Alpha channel of each layer is clamped to avoid weird value.

- It's a clean way to share multiple roto.
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How to use
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1. Type the amount of layers you need

2. Name each layers

3. Set the color of the matte (for display). For a fast way to set a color you can disable/enable 'R' 'G' 'B' channels. You can also set the 'lift' value to 0 and play with the 'multiply' for a bigger range of color.

Format :This will reformat the node to the 'full size format' of the plate (in your project settings). Will prevent having bounding box outside of the frame. It is checked by default.

alpha output : All roto layers are  automatically piped in the alpha channel of the 'roto_renderer' node. You can uncheck the 'alpha output' checkbox from the chosen layer to remove an alpha from the outputted alpha channel.

custom alpha output : Create a new input to plug a custom roto instead of the default alpha output

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Example
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This is the default 'roto_render' node

- In this example, 4 Layers are created: [lamp, armchair, pillow, ladder]
- Layer 4 (ladder) is using a custom color

Result RGB

Result Alpha

A layer for each  object is created. You can extract the alpha with a shuffle node

*** Don't forget to set the 'channels' to 'all' in your write node ***

Updates
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v1.1 :
- Fix nodes not pipping correctly

v1.2 :
- All roto layers are now automatically piped in the alpha channel of the 'roto_renderer' node.

v1.3 :
- Minor script error fix

v1.4 :
- Script Updated for Nuke 13 (bug fix)
Thanks Philippe Pelletier for fixing the node!