blender/blender
162
514
Fork 780
Code Issues 6.8k Pull Requests 928 Projects 19 Wiki Activity

Remaining issues with hair curves #125700

New Issue
Open
opened 2024-07-31 11:35:21 +02:00 by Simon Thommes · 4 comments
Simon Thommes commented 2024-07-31 11:35:21 +02:00
Member
Copy Link

With the new curves type attempting to replace the particle hair system there are a number of issues left that keep us from retiring the legacy system in favor of the new one. These issues are mainly, but not exclusively related to dynamics/animation.
This list is an attempt to bring them all in one task to keep track of them in one view to assess the required effort and see the progress towards that goal.

Notes:

  • This is all besides making the new curves type ready to replace the legacy curves for other use-cases than hair, which also still needs to fill a number of gaps. (#68981, #105253)
  • This is also besides the need for a builtin solution for hair simulation which is a hard requirement to replace the legacy system.

Disclaimer:
At this point the list is not necessarily complete!

Problems that are left:

  • Various workarounds left in node setups because of missing node features
    • merge by distance needs Group ID
    • sample nearest Curve
  • Convenience Features
    • surface geometry fallback
    • default UVmap fallback
    • presets/operators to manage operation order and modifier settings for correct deformation (currently the modular approach makes it non-trivial to avoid jittering hair during animation, which is a commonly reported issue)
    • dynamic node-group/modifier UI based on inputs (hide panels by boolean/enum)
  • replace blackbox Guide Interpolation with node-group
    • lists for multiple guide associations
  • replace blackbox Surface Deform with node-group
  • Surface Attribute Interpolation
    • generate+interpolate creates redundancy and collision, sincegenerate already samples the surface attributes and stores them per guide. Interpolate interpolates the existing attributes between guides, rather than using the ones sampled on the surface points.
  • User Confusion/Problems with modifier order for stable animation
  • UV smoothing under Subdivision creating discrepancy/invalid curves
  • Rest position attribute yielding inaccuracy with Subdivision
    • Interpolation settings per attribute
  • Curve Deformation lacking option to use guide deformation (e.g. clump tips)
With the new curves type attempting to replace the particle hair system there are a number of issues left that keep us from retiring the legacy system in favor of the new one. These issues are mainly, but not exclusively related to dynamics/animation. This list is an attempt to bring them all in one task to keep track of them in one view to assess the required effort and see the progress towards that goal. Notes: - This is all besides making the new curves type ready to replace the legacy curves for other use-cases than hair, which also still needs to fill a number of gaps. (#68981, #105253) - This is also besides the need for a builtin solution for hair simulation which is a hard requirement to replace the legacy system. Disclaimer: At this point the list is not necessarily complete! ### Problems that are left: - [ ] Various workarounds left in node setups because of missing node features - [ ] merge by distance needs Group ID - [ ] sample nearest Curve - [ ] Convenience Features - [ ] surface geometry fallback - [ ] default UVmap fallback - [ ] presets/operators to manage operation order and modifier settings for correct deformation (currently the modular approach makes it non-trivial to avoid jittering hair during animation, which is a commonly reported issue) - [ ] dynamic node-group/modifier UI based on inputs (hide panels by boolean/enum) - [ ] replace blackbox Guide Interpolation with node-group - [ ] lists for multiple guide associations - [ ] replace blackbox Surface Deform with node-group - [ ] [Discontinuity in geonode hair/fur when surface mesh is under deformation due to lack of tangent interpolation](https://projects.blender.org/blender/blender/issues/128184) - [ ] default surface tangent space - [ ] [Surface Attribute Interpolation](https://projects.blender.org/blender/blender/issues/122878) - [ ] generate+interpolate creates redundancy and collision, sincegenerate already samples the surface attributes and stores them per guide. Interpolate interpolates the existing attributes between guides, rather than using the ones sampled on the surface points. - [ ] [User Confusion/Problems with modifier order for stable animation](https://projects.blender.org/blender/blender/issues/109285) - [ ] UV smoothing under Subdivision creating discrepancy/invalid curves - [ ] Rest position attribute yielding inaccuracy with Subdivision - [ ] Interpolation settings per attribute - [ ] Curve Deformation lacking option to use guide deformation (e.g. clump tips)
👍 5
Simon Thommes added the
Type
To Do
 label 2024-07-31 11:35:22 +02:00
Simon Thommes added this to the Nodes & Physics project 2024-07-31 11:35:22 +02:00
Ducktor commented 2024-09-26 00:59:30 +02:00
Copy Link

default surface tangent space

Is this referring to how the surface deform node doesn't interpolate tangents across the surface of the mesh, leading to discontinuity in stuff like fur when the surface mesh is under deformation?

> default surface tangent space Is this referring to how the surface deform node doesn't interpolate tangents across the surface of the mesh, leading to discontinuity in stuff like fur when the surface mesh is under deformation?
Simon Thommes commented 2024-09-26 12:01:31 +02:00
Author
Member
Copy Link

@Ducktor-Cid might be tangentially related, but this is more just about explicitly accessing mesh tangents in a way that they can be attached to a UV space to make sure they are stable.

Would be good if you could specifically report the issue you are referring to, so we can see if it's related to an existing one or track it separately and refer to it here in this task.

@Ducktor-Cid might be tangentially related, but this is more just about explicitly accessing mesh tangents in a way that they can be attached to a UV space to make sure they are stable. Would be good if you could specifically report the issue you are referring to, so we can see if it's related to an existing one or track it separately and refer to it here in this task.
Ducktor commented 2024-09-26 15:03:31 +02:00
Copy Link

@SimonThommes Done. Issue can be found here: #128184

@SimonThommes Done. Issue can be found here: #128184
Simon Thommes commented 2024-09-26 15:24:30 +02:00
Author
Member
Copy Link

Thanks, I added it to the list

Thanks, I added it to the list
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
Nodes & Physics
Assignees
Clear assignees
No Assignees
2 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#125700
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?