Attribute Names for Multiple Domains #86206

New Issue

Hans Goudey · 2021-03-02T21:14:48+01:00

Hans Goudey commented

2021-03-02 21:14:48 +01:00

Many planned attributes can exist on multiple domains:

Normals Point, Face, Corner
Index Point, Face, Edge, Corner
...

While the attribute system could try to automatically choose which domain based on a single name (i.e. we have multiple attributes with the same name), it's very nice to know explicitly which domain the data comes from, and many things become simpler to the user and the code when we don't try to handle the case of multiple attributes with the same name.

So we discussed using a different name for each domain. Here is one initial proposal:

normal
face_normal
corner_normal
point_index
edge_index
face_index
corner_index

It was suggested to put the domain name after the attribute name like normal_corner, however, the resulting combinations sound quite unnatural, and even a bit incorrect (i.e. index_edge), so I would actually prefer not to do that.

The idea with normal was that vertex normals are the most common, so we don't need to repeat "vertex" at the beginning of the name, just for brevity. However, I'm beginning to question that too, since vertex normals are read-only, it seems strange to emphasize them with a special name.

With all that said, here is my proposal for a naming pattern for multi-domain attributes:

vertex_normal Use the full name here, it's long but it's clear
face_normal
corner_normal
point_index Use the name of the domain, because point clouds would have "point_index" too
edge_index
face_index
corner_index

We have talked about this a few times, but I wanted to clarify the ideas and push a little bit more, because this is an important decision, attribute names are not easy to change later with versioning, and also my opinions have changed slightly.

Many planned attributes can exist on multiple domains: - **Normals** Point, Face, Corner - **Index** Point, Face, Edge, Corner - ... While the attribute system could try to automatically choose which domain based on a single name (i.e. we have multiple attributes with the same name), it's very nice to know explicitly which domain the data comes from, and many things become simpler to the user and the code when we don't try to handle the case of multiple attributes with the same name. So we discussed using a different name for each domain. Here is one initial proposal: - `normal` - `face_normal` - `corner_normal` - `point_index` - `edge_index` - `face_index` - `corner_index` It was suggested to put the domain name after the attribute name like `normal_corner`, however, the resulting combinations sound quite unnatural, and even a bit incorrect (i.e. `index_edge`), so I would actually prefer not to do that. The idea with `normal` was that vertex normals are the most common, so we don't need to repeat "vertex" at the beginning of the name, just for brevity. However, I'm beginning to question that too, since vertex normals are read-only, it seems strange to emphasize them with a special name. With all that said, here is my proposal for a naming pattern for multi-domain attributes: - `vertex_normal` *Use the full name here, it's long but it's clear* - `face_normal` - `corner_normal` - `point_index` *Use the name of the domain, because point clouds would have "point_index" too* - `edge_index` - `face_index` - `corner_index` *We have talked about this a few times, but I wanted to clarify the ideas and push a little bit more, because this is an important decision, attribute names are not easy to change later with versioning, and also my opinions have changed slightly.*

Hans Goudey self-assigned this 2021-03-02 21:14:48 +01:00

Hans Goudey commented

2021-03-02 21:14:48 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Hans Goudey commented

2021-03-02 21:14:48 +01:00

Added subscribers: @HooglyBoogly, @JacquesLucke, @SimonThommes, @pablovazquez, @dfelinto

Hans Goudey commented

2021-03-03 23:52:42 +01:00

We talked about this earlier today. The team doesn't seem to have very strong opinions about the attribute names e.g. "normal" vs. "vertex_normal". But the consensus was that "vertex_normal" is okay.

Another piece of feedback is that index should not be handled as an attribute, but rather an expression. For example, if the attribute isn't displayed by the spreadsheet and it isn't stored as an attribute on the geometry data, is it really an attribute?
On the other hand, the difference is not that apparent on the user level anyway, and attribute system would be a nice shortcut to expose indices. This needs a bit more thinking though.

We talked about this earlier today. The team doesn't seem to have very strong opinions about the attribute names e.g. "normal" vs. "vertex_normal". But the consensus was that "vertex_normal" is okay. Another piece of feedback is that index should not be handled as an attribute, but rather an expression. For example, if the attribute isn't displayed by the spreadsheet and it isn't stored as an attribute on the geometry data, is it really an attribute? On the other hand, the difference is not that apparent on the user level anyway, and attribute system would be a nice shortcut to expose indices. This needs a bit more thinking though.

Charlie Jolly commented

2021-03-05 01:39:33 +01:00

Added subscriber: @CharlieJolly

Charlie Jolly commented

2021-03-05 01:39:33 +01:00

From a user perspective I'd like to use indices as though they were a read-only attribute but perhaps cleaner to have an Index to Attribute node? 🤔

From a user perspective I'd like to use indices as though they were a *read-only attribute* but perhaps cleaner to have an **Index to Attribute** node? 🤔

blender-admin commented

2021-03-05 22:16:25 +01:00

This issue was referenced by f117ea2624

This issue was referenced by f117ea26246355f423fd78785a3b00a2490bd9a4

Dalai Felinto commented

2021-03-22 14:57:01 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Dalai Felinto closed this issue

2021-03-22 14:57:01 +01:00

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Attribute Names for Multiple Domains #86206