Slow Parent option doesn't work with new Depsgraph #55026
Labels
No Label
Interest
Alembic
Interest
Animation & Rigging
Interest
Asset Browser
Interest
Asset Browser Project Overview
Interest
Audio
Interest
Automated Testing
Interest
Blender Asset Bundle
Interest
BlendFile
Interest
Collada
Interest
Compatibility
Interest
Compositing
Interest
Core
Interest
Cycles
Interest
Dependency Graph
Interest
Development Management
Interest
EEVEE
Interest
EEVEE & Viewport
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
Virtual Reality
Interest
Vulkan
Interest
Wayland
Interest
Workbench
Interest: X11
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
EEVEE & Viewport
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
Platform
FreeBSD
Platform
Linux
Platform
macOS
Platform
Windows
Priority
High
Priority
Low
Priority
Normal
Priority
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
6 Participants
Notifications
Due Date
No due date set.
Dependencies
No dependencies set.
Reference: blender/blender#55026
Loading…
Reference in New Issue
No description provided.
Delete Branch "%!s(<nil>)"
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?
System Information
Windows 10, GTX780
Blender Version
Broken: 2.79
5bd8ac9
with --enable-new-depsgraphWorked: 2.79
5bd8ac9
with old depsgraphShort description of error
Using Blender 2.79 with new Depsgraph activated on launch makes the Relations Extras option "Slow Parent" stop working. The "Offset" parameter to determine how many frames of delay the parent relationship will have simply have no effect at all, and the Child object will follow without any delay at all.
Exact steps for others to reproduce the error
Open 2.79 using a bat file with steps to enable New Depsgraph (look online for instructions). Create two objects, parent one to another, and set the Child object to have a Slow Parent under the Relations Extras section of the Object Data tab. Set an Offset value that is greater than 1 and move the parent object around. You should see the Child object move delayed in relation to it's parent (do the same steps on 2.79 default launch), but this doesn't work with New Depsgraph activated.
I'm aware that blender 2.8 will work based on this/a new Depsgraph also... therefore I think it's important to make sure that the reason the Slow Parent stops working under the new Depsgraph is known, so that on 2.8 this problem doesn't persist.
This Slow parenting option is very useful for certain cases where one would need to do transformations to the Child position in it's Local Space using a Constraint for example. If you use Drivers instead to emulate Slow Parent, the constraints are kind of ignored because Drivers have priority over constraints I think.
slowparent.blend
Edit: Sample (working) file uploaded. Use the "--enable-new-depsgraph" command on a new blender instance to see that the slow parenting option breaks.
Added subscriber: @EvandroFerreiradaCosta
Added subscribers: @Sergey, @JoshuaLeung, @lichtwerk
Changed status from 'Open' to: 'Archived'
Pretty sure "slow parent" wont come back. There are a couple of comments in code that give an idea:
New codepath (new depsgraph) simply ignores this.
old route:
BKE_object_where_is_calc_time_ex()
and thereforsolve_parenting()
and thereforwhere_is_object_parslow()
new depsgraph:
BKE_object_eval_parent()
note the comment for
BKE_object_eval_parent()
as wellAlso quoting @JoshuaLeung from here:
@EvandroFerreiradaCosta: If you have trouble setting up an alternative to this, please ask around in stackexchange or similar (or even here if there is a bug involved)
But, I dare to archive this, unless @JoshuaLeung or @Sergey have something to add?
Added subscriber: @FrancescoArena
hi, with blender 2.80.41 date: 2019-01-16 21:59, hash:
e57ee5934a
the error persists (win8.1).we must wait for the new depsgraph to fix this problem or I misunderstood?
I can try to give @Sergey another poke to share thoughts on this, but still pretty sure this wont come back.
Actually, I am pretty sure this thing could be removed in 2.8 [since old depsgraph is gone]?
I personally find the old behavior rather unpredictable, hard to work with and unreliable. Here are just some notes:
The latter one has same roots as compatibility with Copy-on-Write environment which is default in 2.8 and brings a lot of other possibilities (as in, we can not go away from CoW, or make it optional).
I wouldn't mind if this feature was properly implemented, but there is still some group work to be finished first. For until then i would prefer to have the option removed from the interface and commented out in the code (or even removed, since it will be re-implemented in a different way anyway).
Added subscriber: @MetinSeven-1
Hi,
If Slow Parent has been removed, is there an easy other way to establish the delay effect for children, driven by one object?
Thanks,
Metin
Added subscriber: @softyoda
Hello, I would be disappointed to know that the slow parent would probably not be present in the new version of blender, indeed, although originally it was used a lot for cameras on the BGE, it still remains very useful in some cases, such as here, or I try to animate a car with hydraulic suspensions that react to the animated terrain.
Here is a GIF of the technique used under blender 2.79 (excuse the beauty of the modeling, it's a demonstration) :
If you want to know the technique, here is the tutorial in picture
You can maby implement in another option, maybe a slow parent node in animation node?
As far as I know, on 2.79 you had another option, which is not so easy...using python scripts or scripted expressions on drivers... I was really interested in this stuff a couple years back:
Check Rich Sedman answer here:
https://blender.stackexchange.com/questions/61780/moving-objects-create-wind/61804#61804
Or Leander answer here:
https://blender.stackexchange.com/questions/106612/while-loop-drivers-and-additive-movement
Or Rich Sedman's example here:
https://blender.stackexchange.com/questions/108373/adding-a-delay-for-a-driver
None are as easy as using Slow Parent though.