blender/blender
163
511
Fork 773
Code Issues 6.7k Pull Requests 905 Projects 18 Wiki Activity

Bug: Endpoint curve node version compatibilty #107433

New Issue
Closed
opened 2023-04-28 13:29:46 +02:00 by Arye Ramaty · 3 comments
Arye Ramaty commented 2023-04-28 13:29:46 +02:00
Contributor
Copy Link

System Information
Operating system: Linux-5.19.0-40-generic-x86_64-with-glibc2.35 64 Bits
Graphics card: NVIDIA GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 510.108.03

Blender Version
Broken: version: 3.5.0 Alpha, branch: master, commit date: 2022-11-21 01:31, hash: rB7a6cdeb24279
Worked: version: 3.5.0 Alpha, branch: arcpatch-D16471, commit date: 2022-11-18 20:37, hash: rB48cfe11fa60d

Behavior changed in e83f46ea76.

Short description of error
The GN setup functions differently in versions 3.41 and 3.5. After gradually freezing the GN setup and adding it as mesh data, I discovered that one of these three nodes - Capture Attribute, Endpoint Selection, or Mesh to Curve - is the cause. The images attached illustrate that the same node setup results in a different number of vertices.

3.4 3.5
GN_Bug_3.41.png GN_Bug_3.5.png

Exact steps for others to reproduce the error
Download the attached blend file,
Open it in Blender 3.4 and 3.5.
See the differences in behavior.
[Based on the default startup or an attached .blend file (as simple as possible)]
GN bug report.blend

**System Information** Operating system: Linux-5.19.0-40-generic-x86_64-with-glibc2.35 64 Bits Graphics card: NVIDIA GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 510.108.03 **Blender Version** Broken: version: 3.5.0 Alpha, branch: master, commit date: 2022-11-21 01:31, hash: `rB7a6cdeb24279` Worked: version: 3.5.0 Alpha, branch: arcpatch-D16471, commit date: 2022-11-18 20:37, hash: `rB48cfe11fa60d` Behavior changed in e83f46ea7630163ae836f04cff867eee99032efa. **Short description of error** The GN setup functions differently in versions 3.41 and 3.5. After gradually freezing the GN setup and adding it as mesh data, I discovered that one of these three nodes - Capture Attribute, Endpoint Selection, or Mesh to Curve - is the cause. The images attached illustrate that the same node setup results in a different number of vertices. | 3.4 | 3.5 | | -- | -- | | ![GN_Bug_3.41.png](/attachments/e71fadba-d550-4e50-8a8b-254448d7e3a1) | ![GN_Bug_3.5.png](/attachments/f35f4012-bbce-4d8e-844d-5bbfa7de803f) | **Exact steps for others to reproduce the error** Download the attached blend file, Open it in Blender 3.4 and 3.5. See the differences in behavior. [Based on the default startup or an attached .blend file (as simple as possible)] [GN bug report.blend](/attachments/aecf7f94-f1ff-4e78-a42a-25165014297a)
GN_Bug_3.41.png
371 KiB
GN_Bug_3.5.png
374 KiB
GN bug report.blend
910 KiB
Arye Ramaty added the
Severity
Normal
Type
Report
Status
Needs Triage
 labels 2023-04-28 13:29:47 +02:00
Iliya Katushenock commented 2023-04-28 14:13:30 +02:00
Member
Copy Link
3.4 3.6
image image
| 3.4 | 3.6 | | -- | -- | | ![image](/attachments/a5b0b512-75a6-4390-ba80-9c25dc5e07c1) | ![image](/attachments/5632b801-3a0d-4345-bc9f-64b7dd291539) |
image.png
99 KiB
image.png
98 KiB
Philipp Oeser commented 2023-05-02 16:09:20 +02:00
Member
Copy Link

Behavior changed in e83f46ea76.

Since this was a "identical results compared to the BMesh version" commit, will raise prio to check results again.

CC @wannes.malfait
CC @HooglyBoogly

Behavior changed in e83f46ea7630163ae836f04cff867eee99032efa. Since this was a "identical results compared to the BMesh version" commit, will raise prio to check results again. CC @wannes.malfait CC @HooglyBoogly
Wannes Malfait commented 2023-05-05 22:03:49 +02:00
Member
Copy Link

I don't think this is actually a "bug". Let me explain why:

I did some research into what exactly was causing the difference in output. Since the relevant commit was found to be a refactor of the edge split node, the problem should occur there. This is what I found:

  • The output of the "new" edge split node is correct: I manually checked that each edge that should get split gets split, and that the number of vertices and edges is correct. I then verified this with an older version of blender using the "old" edge split node. The number of vertices and edges is exactly the same, and the connectivity is also the same.
  • There is a difference in the output of the two versions of the node: the order of the edges is different! This is something that happens due to a slightly different algorithm being used to sort edges around a vertex.
  • Later on in the tree, some nodes produce different outputs because they implicitly rely on the ordering of the edges (like the mesh to curve node for the orientation of the curves). This causes the final output to be different between the different versions of blender.

In any case, there is no real way to "fix" this difference without reverting to the older version of the edge split node, which is not desirable. After all the newer version is much faster, and can take advantage of multiple cpu cores. Since geometry nodes tries to avoid the use of indices as much as possible anyway, I don't think that this report is a compelling enough reason to revert.

I don't think this is actually a "bug". Let me explain why: I did some research into what exactly was causing the difference in output. Since the relevant commit was found to be a refactor of the edge split node, the problem should occur there. This is what I found: - The output of the "new" edge split node is correct: I manually checked that each edge that should get split gets split, and that the number of vertices and edges is correct. I then verified this with an older version of blender using the "old" edge split node. The number of vertices and edges is exactly the same, and the connectivity is also the same. - There is a difference in the output of the two versions of the node: the order of the edges is different! This is something that happens due to a slightly different algorithm being used to sort edges around a vertex. - Later on in the tree, some nodes produce different outputs because they implicitly rely on the ordering of the edges (like the mesh to curve node for the orientation of the curves). This causes the final output to be different between the different versions of blender. In any case, there is no real way to "fix" this difference without reverting to the older version of the edge split node, which is not desirable. After all the newer version is much faster, and can take advantage of multiple cpu cores. Since geometry nodes tries to avoid the use of indices as much as possible anyway, I don't think that this report is a compelling enough reason to revert.
Blender Bot added
Status
Archived
 and removed
Status
Confirmed
 labels 2023-05-05 22:03:53 +02:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels   
Interest
Alembic

  
Interest
Animation & Rigging

  
Interest
Asset System
Asset datablocks, libraries, browser and shelf

  
Interest
Audio

  
Interest
Automated Testing

  
Interest
Blender Asset Bundle

  
Interest
BlendFile

  
Interest
Code Documentation
Code comments, Python/RNA API descriptions

  
Interest
Collada

  
Interest
Compatibility
Backward and forward compatibility

  
Interest
Compositing

  
Interest
Core

  
Interest
Cycles

  
Interest
Dependency Graph

  
Interest
Development Management

  
Interest
EEVEE

  
Interest
Freestyle

  
Interest
Geometry Nodes

  
Interest
Grease Pencil

  
Interest
ID Management

  
Interest
Images & Movies

  
Interest
Import Export

  
Interest
Line Art

  
Interest
Masking

  
Interest
Metal

  
Interest
Modeling

  
Interest
Modifiers

  
Interest
Motion Tracking

  
Interest
Nodes & Physics

  
Interest
OpenGL

  
Interest
Overlay

  
Interest
Overrides

  
Interest
Performance

  
Interest
Physics

  
Interest
Pipeline, Assets & IO

  
Interest
Platforms, Builds & Tests

  
Interest
Python API

  
Interest
Render & Cycles

  
Interest
Render Pipeline

  
Interest
Sculpt, Paint & Texture

  
Interest
Text Editor

  
Interest
Translations

  
Interest
Triaging

  
Interest
Undo

  
Interest
USD

  
Interest
User Interface

  
Interest
UV Editing

  
Interest
VFX & Video

  
Interest
Video Sequencer

  
Interest
Viewport & EEVEE

  
Interest
Virtual Reality

  
Interest
Vulkan

  
Interest
Wayland
Wayland windowing on Unix

  
Interest
Workbench

  
Interest: X11

Xorg/X11 windowing

  
Legacy
Asset Browser Project

Archived

  
Legacy
Blender 2.8 Project

Archived

  
Legacy
Milestone 1: Basic, Local Asset Browser

Archived

  
Legacy
OpenGL Error

Archived

  
Meta
Good First Issue

  
Meta
Papercut

  
Meta
Retrospective

  
Meta
Security
Related to security, see policy: https://developer.blender.org/docs/handbook/bug_reports/vulnerability_reports/

  
Module
Animation & Rigging

  
Module
Core

  
Module
Development Management

  
Module
Grease Pencil

  
Module
Modeling

  
Module
Nodes & Physics

  
Module
Pipeline, Assets & IO

  
Module
Platforms, Builds & Tests

  
Module
Python API

  
Module
Render & Cycles

  
Module
Sculpt, Paint & Texture

  
Module
Triaging

  
Module
User Interface

  
Module
VFX & Video

  
Module
Viewport & EEVEE

  
Platform
FreeBSD

  
Platform
Linux

  
Platform
macOS

  
Platform
Windows

  
Severity
High

  
Severity
Low

  
Severity
Normal

  
Severity
Unbreak Now!

  
Status
Archived

  
Status
Confirmed

  
Status
Duplicate

  
Status
Needs Info from Developers

  
Status
Needs Information from User

  
Status
Needs Triage

  
Status
Resolved

  
Type
Bug

  
Type
Design

  
Type
Known Issue

  
Type
Patch

Archived

  
Type
Report

Archived

  
Type
To Do

No Label
Interest
Alembic
Interest
Animation & Rigging
Interest
Asset System
Interest
Audio
Interest
Automated Testing
Interest
Blender Asset Bundle
Interest
BlendFile
Interest
Code Documentation
Interest
Collada
Interest
Compatibility
Interest
Compositing
Interest
Core
Interest
Cycles
Interest
Dependency Graph
Interest
Development Management
Interest
EEVEE
Interest
Freestyle
Interest
Geometry Nodes
Interest
Grease Pencil
Interest
ID Management
Interest
Images & Movies
Interest
Import Export
Interest
Line Art
Interest
Masking
Interest
Metal
Interest
Modeling
Interest
Modifiers
Interest
Motion Tracking
Interest
Nodes & Physics
Interest
OpenGL
Interest
Overlay
Interest
Overrides
Interest
Performance
Interest
Physics
Interest
Pipeline, Assets & IO
Interest
Platforms, Builds & Tests
Interest
Python API
Interest
Render & Cycles
Interest
Render Pipeline
Interest
Sculpt, Paint & Texture
Interest
Text Editor
Interest
Translations
Interest
Triaging
Interest
Undo
Interest
USD
Interest
User Interface
Interest
UV Editing
Interest
VFX & Video
Interest
Video Sequencer
Interest
Viewport & EEVEE
Interest
Virtual Reality
Interest
Vulkan
Interest
Wayland
Interest
Workbench
Interest: X11
Legacy
Asset Browser Project
Legacy
Blender 2.8 Project
Legacy
Milestone 1: Basic, Local Asset Browser
Legacy
OpenGL Error
Meta
Good First Issue
Meta
Papercut
Meta
Retrospective
Meta
Security
Module
Animation & Rigging
Module
Core
Module
Development Management
Module
Grease Pencil
Module
Modeling
Module
Nodes & Physics
Module
Pipeline, Assets & IO
Module
Platforms, Builds & Tests
Module
Python API
Module
Render & Cycles
Module
Sculpt, Paint & Texture
Module
Triaging
Module
User Interface
Module
VFX & Video
Module
Viewport & EEVEE
Platform
FreeBSD
Platform
Linux
Platform
macOS
Platform
Windows
Severity
High
Severity
Low
Severity
Normal
Severity
Unbreak Now!
Status
Archived
Status
Confirmed
Status
Duplicate
Status
Needs Info from Developers
Status
Needs Information from User
Status
Needs Triage
Status
Resolved
Type
Bug
Type
Design
Type
Known Issue
Type
Patch
Type
Report
Type
To Do
Milestone
Clear milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
No Assignees
4 Participants
Notifications
Due Date
The due date is invalid or out of range. Please use the format 'yyyy-mm-dd'.

No due date set.

Dependencies

No dependencies set.

Reference: blender/blender#107433
No description provided.
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?