Attribute References in Modifiers #117893

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Campbell Barton · 2024-02-06T13:04:28+01:00

Campbell Barton commented

2024-02-06 13:04:28 +01:00

Motivation

A PR has been submitted that adds attribute names to the bevel modifier #117366.

Consistent conventions should be used for referencing attributes between different areas of Blender.

Proposal

Updated based on feedback.

Limited use of attributes for modifiers.
- We don't accept adding arbitrary attributes to any modifiers that support vertex groups (if such patches are submitted).
- Support for attributes is limited to previously hard coded flags (bevel, crease, sharp...).
We could consider extending places where attributes are used in modifiers at some point.
Handle names as follows:
- Existing modifiers must be versioned to have the default custom-data layer names initialized.
- An empty string skips loading any custom-data layers (behaves as if the layer is missing).
- Clicking on the name shows a drop-down list of names (as with vertex groups), this includes the default name.
- Renaming an attribute updates the modifier names accordingly.

## Motivation A PR has been submitted that adds attribute names to the bevel modifier #117366. Consistent conventions should be used for referencing attributes between different areas of Blender. ## Proposal **Updated based on feedback.** - Limited use of attributes for modifiers. - We don't accept adding arbitrary attributes to any modifiers that support vertex groups (if such patches are submitted). - Support for attributes is limited to previously hard coded flags (bevel, crease, sharp...). *We could consider extending places where attributes are used in modifiers at some point.* - Handle names as follows: - Existing modifiers must be versioned to have the default custom-data layer names initialized. - An empty string skips loading any custom-data layers (behaves as if the layer is missing). - Clicking on the name shows a drop-down list of names (as with vertex groups), this includes the default name. - Renaming an attribute updates the modifier names accordingly.

Campbell Barton added the

labels 2024-02-06 13:04:28 +01:00

Campbell Barton commented

2024-02-06 13:08:55 +01:00

Created this task to settle on conventions before accepting #117366.
There may be existing conventions here I'm unaware of.

CC'ing @HooglyBoogly, @brecht & @howardt.

Created this task to settle on conventions before accepting #117366. There may be existing conventions here I'm unaware of. CC'ing @HooglyBoogly, @brecht & @howardt.

Campbell Barton referenced this issue

2024-02-06 13:17:19 +01:00

UI: Add custom attribute edge groups for bevel modifier #117366

Hans Goudey commented

2024-02-07 02:18:45 +01:00

Since we aim to replace builtin modifiers with geometry nodes completely long term, I think we should focus on aligning behavior with nodes or at least keeping a simple transition in the future.

An empty string (default) uses the default attribute, so bevel would use "bevel_weight_edge" for instance.

I would rather see the naming convention filled in the modifier's name property by default. That behavior is less magical, simpler, and teaches users at the same time.

Clicking on the name shows a drop-down list of names (as with vertex groups), this includes the default name.

For geometry nodes this is already implemented with the attribute search system. It uses logged data from the last evaluation to give more accurate results as geometry changes during evaluation. I don't think it's worth making a new attribute search suggestion system for the transition period in these very few cases.

Renaming an attribute updates the modifier names accordingly.

This worked in general with the imagined use cases for vertex groups years ago, where it was always a simple question of using the name from the original object. It's more complicated nowadays, with attributes generated procedurally, transferred from other objects, etc. I don't think this should be considered for this discussion, it's a more broad topic. Either way we decide eventually, it should be implemented for geometry nodes, then for the legacy builtin modifiers if it's a priority.

Since we aim to replace builtin modifiers with geometry nodes completely long term, I think we should focus on aligning behavior with nodes or at least keeping a simple transition in the future. >An empty string (default) uses the default attribute, so bevel would use "bevel_weight_edge" for instance. I would rather see the naming convention filled in the modifier's name property by default. That behavior is less magical, simpler, and teaches users at the same time. >Clicking on the name shows a drop-down list of names (as with vertex groups), this includes the default name. For geometry nodes this is already implemented with the attribute search system. It uses logged data from the last evaluation to give more accurate results as geometry changes during evaluation. I don't think it's worth making a new attribute search suggestion system for the transition period in these very few cases. >Renaming an attribute updates the modifier names accordingly. This worked in general with the imagined use cases for vertex groups years ago, where it was always a simple question of using the name from the original object. It's more complicated nowadays, with attributes generated procedurally, transferred from other objects, etc. I don't think this should be considered for this discussion, it's a more broad topic. Either way we decide eventually, it should be implemented for geometry nodes, then for the legacy builtin modifiers if it's a priority.

Campbell Barton commented

2024-02-07 09:52:56 +01:00

@HooglyBoogly thanks for the feedback, updated the proposal.