Replace legacy curve code with new system #105253
Labels
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
No Milestone
No project
No Assignees
3 Participants
Notifications
Due Date
No due date set.
Dependencies
No dependencies set.
Reference: blender/blender#105253
Loading…
Reference in New Issue
Block a user
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?
Feature Replacement / Versioning
Cleanup
OB_CURVES_LEGACY
CurveCache
References
Replace the old curves code with the new oneto Replace the old curves code with the new one for 4.0Replace the old curves code with the new one for 4.0to Replace legacy curve code with new systemDoes this also affect the text object?
Thomas Dinges referenced this issue2023-03-07 11:07:33 +01:00
I'd like to thoroughly explain a fundamental limitation with rigging with curves, specifically about Twist, in hopes that it might give a chance for the new curve system to provide a solution.
Let's say you want to rig a dino's tail:
The standard setup: Object is deformed by a Curve Modifier, and the curve is deformed with bones via Hooks.
The curve and everything else is parented to the big bone in the middle, so rotating that works fine.
But the other bones just control curve points via Hook modifiers, and since those don't affect twist, you simply cannot twist only a part of this dino tail (such that the spikes point downwards).
Bad Solution 1: Try to drive the Tilt of the curve points with a bone transform.
Well, this works... Except, what space? With Local Space, it will fail as soon as the rotation is coming from a parent.
With Pose Space... Well, drivers don't have a Pose Space option, but we can convert their Local Space to Pose Space by using an Armature Constraint instead of parenting.
It's a step up, but flipping the bones upside down fails to flip the mesh upside down. I sort of understand why, but not well enough to explain it. And our tilt drivers don't help at all with this case. We can experiment with the different Twist Methods, and quickly find that none of them fix this issue.
Bad Solution 2: Just use Bendy Bones.
Bendy Bones don't struggle with twist and behave how one would expect. However, Bendy Bones deform meshes with the Armature Modifier, and that's not the same as curve deform; You can't shape the curvature of the deformation without squashing and stretching the bones.
And that's pretty much it. You just can't use curves to rig things that need to flip around or rotate a lot, because you'll run into issues with twist, no matter what you do. Sorry for the wall of text.
Here's the .blend file to play with: dino_tail.blend
Do you guys think this is a solvable problem for the new curve type?