Node Editor: Improve working with frame nodes #106956

New Issue

Leon Schittek · 2023-04-14T16:22:06+02:00

Leon Schittek commented

2023-04-14 16:22:06 +02:00

Problem

Working with frame nodes works well for most simple cases, but there are a few things that are confusing or cumbersome:

A node sitting on top of a frame is not necessarily part of the frame but there is no visual indication (example video)
Which frame a node is being added to during transform is based on the position of the mouse cursor and can lead to unexpected results (example video, also see issue #80218)
Nodes not being able to be removed from frames, slows down the workflow, since the user has to stop and explicitly detach the node

Proposal

After testing a few different variations for how this could work (together with users on the forums), this is what seemed to work best overall:

Nodes should always be attached to the frames that include them
- This reduces ambiguous situations, where nodes are on top of a frame without being part of it
- This behavior is more predictable than the cursor based attachment logic we have now
Allow detaching nodes during transform with a hotkey
- Pressing Shift during transform to freely drag nodes out of a frame - even if "Shrink" is enabled (Shift is consistent with the re-parenting shortcut in the outliner)
Allow adding/removing nodes from a frame by resizing it
Additionally tweak node resizing, since it will be used more often:
- Allow moving the frame during resizing by pressing Space (same as box selection, demovideo)
- Improve hitzone for resizing to make it more accessible

Alternative: Remove "parenting"

The most promising alternative I tried was to remove parenting altogether. The premise was that frames simply always affect the nodes that are inside them.

What worked well:

No ambiguity about whether a node is inside a frame or not
Users seemed to like the ability to add nodes by resizing the frames itself (which has been included in the current proposal)

What didn't work:

Users didn't seem to like how multiple frames were able to affect one node at the same time:
- In some situation it would lead to partially overlapping frames "stealing" nodes from one another
- Overall users feared that it would be easy to create situations that are hard to untangle

Since "node stealing" is inherent to this approach, I settled on the proposed compromise that keeps the "one node, one frame" concept but reduces some of the quirqs.

Prototype Patch

A pull request implementing the proposed changes for testing can be found here: #105457

Steps for implementation

The prototype patch I've used for testing can be broken up into a few smaller changes:

Always add nodes to the frames they overlap
Improve resizing of nodes:
- Hitzone for node resizing
- Allow moving nodes during resizing
- Respect snapping during resizing (I haven't actually implemented this in the prototype)

There are a few more things that are not required for this but might be nice:

Improve how the parenting of nodes to frames is propagated when deleting or grouping nodes.
Remove the "parent space" positioning of nodes so the node location is always in view space. I think this could also help removing the need for offsetx and offsety.

### Problem Working with frame nodes works well for most simple cases, but there are a few things that are confusing or cumbersome: * A node sitting on top of a frame is not necessarily part of the frame but there is no visual indication ([example video](/attachments/ee6a20e7-3ba5-4dfa-bd80-0cd8f3cdfa44)) * Which frame a node is being added to during transform is based on the position of the mouse cursor and can lead to unexpected results ([example video](/attachments/cea4b72b-2c03-491a-9c39-4598aceab366), also see issue #80218) * Nodes not being able to be removed from frames, slows down the workflow, since the user has to stop and explicitly detach the node ### Proposal After testing a few different variations for how this could work ([together with users on the forums](https://devtalk.blender.org/t/testing-wanted-for-joining-nodes-into-frames/28241)), this is what seemed to work best overall: 1. Nodes should always be attached to the frames that include them * This reduces ambiguous situations, where nodes are on top of a frame without being part of it * This behavior is more predictable than the cursor based attachment logic we have now 2. Allow detaching nodes during transform with a hotkey * Pressing `Shift` during transform to freely drag nodes out of a frame - even if "Shrink" is enabled (`Shift` is consistent with the re-parenting shortcut in the outliner) 3. Allow adding/removing nodes from a frame by resizing it 4. Additionally tweak node resizing, since it will be used more often: * Allow moving the frame during resizing by pressing `Space` (same as box selection, [demovideo](/attachments/1403aea9-c186-43d6-8d55-f4d796881003)) * Improve hitzone for resizing to make it more accessible ### Alternative: Remove "parenting" The most promising alternative I tried was to remove parenting altogether. The premise was that frames simply always affect the nodes that are inside them. **What worked well:** * No ambiguity about whether a node is inside a frame or not * Users seemed to like the ability to add nodes by resizing the frames itself (which has been included in the current proposal) **What didn't work:** * Users didn't seem to like how multiple frames were able to affect one node at the same time: * In some situation it would lead to partially overlapping frames "stealing" nodes from one another * Overall users feared that it would be easy to create situations that are hard to untangle Since "node stealing" is inherent to this approach, I settled on the proposed compromise that keeps the "one node, one frame" concept but reduces some of the quirqs. --- ### Prototype Patch A pull request implementing the proposed changes for testing can be found here: https://projects.blender.org/blender/blender/pulls/105457 --- ### Steps for implementation The prototype patch I've used for testing can be broken up into a few smaller changes: - [ ] Always add nodes to the frames they overlap - [ ] Improve resizing of nodes: - [x] Hitzone for node resizing - [ ] Allow moving nodes during resizing - [ ] Respect snapping during resizing (I haven't actually implemented this in the prototype) There are a few more things that are not required for this but might be nice: - Improve how the parenting of nodes to frames is propagated when deleting or grouping nodes. - Remove the "parent space" positioning of nodes so the node location is always in view space. I think this could also help removing the need for `offsetx` and `offsety`.

main_ambiguous-frames.mp4

161 KiB

proposal_frame-resizing.mp4

209 KiB

main_confusing-frame-joining.mp4

49 KiB

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Leon Schittek added the

Type

Design

label 2023-04-14 16:22:07 +02:00

Leon Schittek added this to the Nodes & Physics project 2023-04-14 16:22:08 +02:00