2025-04-11 Compositor Meeting Notes

Meetings
1

Attendees:

  • Andy Goralczyk
  • Omar Emara
  • Habib Gahbiche

Roadmap

  • Options as sockets: Started working on exposing options as sockets. Will get priority to try to get it done for 4.5 (Omar)
    • These will be breaking changes, so we will take the opportunity to make other breaking changes (e.g. remove the “Gamma” input from the blur node and remove the “Alpha” and “use alpha” inputs from the Composite and Viewer nodes).
  • Reusable node trees: working on versioning. Might need to delay the feature to 5.0 to ensure forward compatibility (Habib)

Notes:

Proposals:

  • Custom RGB to BW conversion:

    image
    image724×292 31.8 KB

    • Decision: Exposing conversion factors are not valuable but exposing different ways of converting from RGB to BW can be useful (e.g. choose from luminance, average etc…).

  • Remove alpha option from composite and viewer nodes:
    image

    • Agreed. Will be removed in 4.5

UI Updates:

  • Box and Ellipse gizmos are merged
  • Prototype hide nodes while pressing down a button (or a shortcut).
    • Not ideal for Andy, would still like to explore the idea of only hiding the node tree while dragging a slider or a value.
  • Glare node: Suggestion to rename “Suppress” to “Clamp” or “Clamp Highlights”
    • No agreement in the meeting. Will follow up with a post on devtalk
  • Snapping: support snapping for vertical resizing is merged
  • Image info node: resolution doesn’t consider transformation. A few ideas were discussed. Will follow up with a post on devtalk.

Practical Info

This is a fortnightly video chat meeting for planning and discussion of Compositing in Blender. Any contributor (developer, UI/UX designer, writer, …) working on this area in Blender is welcome to join and add proposed items to the agenda.

For users and other interested parties, we ask to read the meeting notes instead so that the meeting can remain focused.

13 Likes
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So…will we still see the alpha (it’s just automatic), or not see it?

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isn’t there a set alpha node?

4

1
Of course

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5

As stated by Nahuel and Bobo, that option was basically just a Set Alpha node built into the Composite and Viewer node, but it is more limited and has some bad UX, that’s why we will remove it. Users can just use a Set Alpha node.

2 Likes
6

So if I want to see my objects with the transparent background, I’ll have to add additional nodes?

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Seconded- how is having to make two nodes for what used to be one better UX than whatever is wrong with the current UX?

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8

I might be wrong, but I’m pretty sure the alpha channel is implicitly carried along with the Image socket (or at least that’s how it works currently).

The Alpha socket is just for overriding that, which does seem a bit arbitrary to me.

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That’s why I asked “what will I see”, not if there are other nodes that have something to do with alpha channels.

IE, when the checkbox is gone - is the alpha inherently now ON or OFF?

10

Ah ok, I’d assume that it would be inherently on then (though maybe not).

In that case, I think it does make sense to remove the checkbox and socket. Replacing the alpha channel is relatively non-standard, and doing it with a “replace alpha” node makes more logical sense to me than doing it in the output node. Having it in the output node seems a bit arbitrary.

2 Likes
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@thorn-neverwake @josephhansen Just like @Strike_Digital said, the node will behave as if the checkbox is enabled. Whatever alpha your output have will be used as is with no adjustments.

7 Likes
12

Good news, thanks for clarifying that.