blender/blender
151
478
Fork 711
Code Issues 6.7k Pull Requests 904 Projects 18 Wiki Activity

Design: Onion Skinning for Blender #102217

New Issue
Open
opened 2022-11-01 23:07:36 +01:00 by Christoph Lendenfeld · 20 comments
Christoph Lendenfeld commented 2022-11-01 23:07:36 +01:00
Member
Copy Link

This is the overarching task to get Onion Skinning functionality into Blender.

Onion Skinning (or Ghosting) is a way of displaying data of a different frame than the current one.
This is useful for animation because they can visually compare poses.

This Design Task serves as a starting point for the conversation in the Animation & Rigging module.
More details will be added later.

The Goal

Implement editable Onion Skinning into Blender, following the FIFIDS principles laid out in the Animation Workshop prior to Blender Con.

The Plan

The proposed plan has 3 stages:

Single Frame Onion Skinning

  • Take a snapshot of a user specified geometry or a subset thereof
  • Learn how to implement overlays into the viewport renderer
  • Shading options (Outline, single color, tinting)
  • tools to position and mask onion skins

The Basics

Important to answer is how the user defines what he wants to display as ghost. Not everything should be ghosted, but rather select geometry defined by the user. The information which objects to ghost should be stored on the scene, so it doesn't need to be defined for every view.
The options to display the ghosts should exist per view though since I can see a use for not displaying ghosts in certain scenarios.

The GUI to access the functions can live in the N panel.
screen_space_ghosting_menu.png

In order to quickly toggle ghosts, it can be added to the overlays panel
screen_space_ghosting_overlay.png

Animation Caching

  • Figure out how to evaluate objects on a frame other than the current one and store the result (check out how motion paths do it)
  • If the animation is stored, make sure it is read when playing back the scene
  • Caching needs to be bullet proof. No stale caches should ever be presented to the user

User interaction to define which frames to display

The information which ghosts to display is stored on the scene and not per area.
That makes it possible to use the timeline to define where to display ghosts and have it sync over all areas.
In order to make the setting of ghosts quickly I propose the following interaction:
ALT+click in the time slider area to toggle relative ghosts (those that travel with the current time)
ALT+SHIFT+click to define pinned ghosts (those that stay on the frame no matter what)
onion_skin_timeline.jpg

Editable Onion Skinning

  • Add the option to edit objects from different frames
  • Most important is performance and intuitive use of the system
**This is the overarching task to get Onion Skinning functionality into Blender.** Onion Skinning (or Ghosting) is a way of displaying data of a different frame than the current one. This is useful for animation because they can visually compare poses. This Design Task serves as a starting point for the conversation in the Animation & Rigging module. More details will be added later. # The Goal Implement editable Onion Skinning into Blender, following the FIFIDS principles laid out in the Animation Workshop prior to Blender Con. # The Plan The proposed plan has 3 stages: ## Single Frame Onion Skinning * Take a snapshot of a user specified geometry or a subset thereof * Learn how to implement overlays into the viewport renderer * Shading options (Outline, single color, tinting) * tools to position and mask onion skins ### The Basics Important to answer is how the user defines what he wants to display as ghost. Not everything should be ghosted, but rather select geometry defined by the user. The information which objects to ghost should be stored on the scene, so it doesn't need to be defined for every view. The options to display the ghosts should exist per view though since I can see a use for not displaying ghosts in certain scenarios. The GUI to access the functions can live in the N panel. ![screen_space_ghosting_menu.png](https://archive.blender.org/developer/F14080323/screen_space_ghosting_menu.png) In order to quickly toggle ghosts, it can be added to the overlays panel ![screen_space_ghosting_overlay.png](https://archive.blender.org/developer/F14080319/screen_space_ghosting_overlay.png) ## Animation Caching * Figure out how to evaluate objects on a frame other than the current one and store the result (check out how motion paths do it) * If the animation is stored, make sure it is read when playing back the scene * Caching needs to be bullet proof. No stale caches should ever be presented to the user ### User interaction to define which frames to display The information which ghosts to display is stored on the scene and not per area. That makes it possible to use the timeline to define where to display ghosts and have it sync over all areas. In order to make the setting of ghosts quickly I propose the following interaction: ALT+click in the time slider area to toggle relative ghosts (those that travel with the current time) ALT+SHIFT+click to define pinned ghosts (those that stay on the frame no matter what) ![onion_skin_timeline.jpg](https://projects.blender.org/attachments/250bcf1f-74bc-4691-8b46-d1d89c1561b7) ## Editable Onion Skinning * Add the option to edit objects from different frames * Most important is performance and intuitive use of the system
onion_skin_timeline.jpg
105 KiB
Christoph Lendenfeld commented 2022-11-01 23:07:36 +01:00
Author
Member
Copy Link

Changed status from 'Needs Triage' to: 'Confirmed'

Changed status from 'Needs Triage' to: 'Confirmed'
Christoph Lendenfeld commented 2022-11-01 23:07:36 +01:00
Author
Member
Copy Link

Added subscriber: @ChrisLend

Added subscriber: @ChrisLend
Christoph Lendenfeld changed title from Onion Skinning for Blender to Design: Onion Skinning for Blender 2022-11-02 09:01:06 +01:00
Iliya Katushenock commented 2022-11-02 10:15:46 +01:00
Member
Copy Link

Added subscriber: @mod_moder

Added subscriber: @mod_moder
RedMser commented 2022-11-03 13:22:35 +01:00
Contributor
Copy Link

Added subscriber: @RedMser

Added subscriber: @RedMser
Brad Clark commented 2022-11-03 19:00:11 +01:00
Member
Copy Link

Added subscriber: @BClark

Added subscriber: @BClark
Yuro commented 2022-11-04 09:38:16 +01:00
Copy Link

Added subscriber: @Yuro

Added subscriber: @Yuro
Andreas commented 2022-11-29 14:27:45 +01:00
Copy Link

Added subscriber: @ndh

Added subscriber: @ndh
Nika Kutsniashvili commented 2022-12-20 15:42:11 +01:00
Contributor
Copy Link

Added subscriber: @Nika-Kutsniashvili

Added subscriber: @Nika-Kutsniashvili
Nika Kutsniashvili commented 2022-12-22 08:29:29 +01:00
Contributor
Copy Link

Hello. I want to give user feedback if that's ok. I like the GUI designs presented and personally, I'll use the N menu one, but I have a lot of 2D animator friends and thought how would they find the settings for it if they opened up Blender for the first time. I decided to check how grease pencil onion skinning worked but couldn't find it myself. It took me minutes of googling, reading blender doc and youtube videos to finally find where they were. Not only that, but turns out there's no on/off switch. I had to reduce number of skins to 0 to make it go away. Not only is it timewasting practice, but absolutely confusing to anyone opening it for the first time. It's gonna be same for the 3D if beginner opens up blender and wants to control ghosts.

image.png

In other softwares I've used there is always on/off switch for onion skinning at either of those places, and since blender already uses those horizontal menu-thingys so well I think it absolutely needs to go there in either of those places. Personally what I would go for would be one button for toggling on/off and next to it arrow icon that opens up same options that are in N menu. Like Show Gizmo/Overlays buttons.

I hope this is helpful. Appreciate all the amazing work you do and can't wait for this feature. Thank you.

Hello. I want to give user feedback if that's ok. I like the GUI designs presented and personally, I'll use the N menu one, but I have a lot of 2D animator friends and thought how would they find the settings for it if they opened up Blender for the first time. I decided to check how grease pencil onion skinning worked but couldn't find it myself. It took me minutes of googling, reading blender doc and youtube videos to finally find where they were. Not only that, but turns out there's no on/off switch. I had to reduce number of skins to 0 to make it go away. Not only is it timewasting practice, but absolutely confusing to anyone opening it for the first time. It's gonna be same for the 3D if beginner opens up blender and wants to control ghosts. ![image.png](https://archive.blender.org/developer/F14082360/image.png) In other softwares I've used there is always on/off switch for onion skinning at either of those places, and since blender already uses those horizontal menu-thingys so well I think it absolutely needs to go there in either of those places. Personally what I would go for would be one button for toggling on/off and next to it arrow icon that opens up same options that are in N menu. Like Show Gizmo/Overlays buttons. I hope this is helpful. Appreciate all the amazing work you do and can't wait for this feature. Thank you.
Christoph Lendenfeld commented 2022-12-22 10:06:41 +01:00
Author
Member
Copy Link

hi @Nika-Kutsniashvili and thanks for the feedback
really appreciated.
I agree the options could live in a separate button. It would work just like the overlay button where you can easily toggle it.
The longer I think about it, the more I like it actually. I'll check with the dev team if there is any reason not to add a new button in the viewport

hi @Nika-Kutsniashvili and thanks for the feedback really appreciated. I agree the options could live in a separate button. It would work just like the overlay button where you can easily toggle it. The longer I think about it, the more I like it actually. I'll check with the dev team if there is any reason not to add a new button in the viewport
Adam Earle commented 2022-12-23 06:05:07 +01:00
Copy Link

Added subscriber: @AdamEarle

Added subscriber: @AdamEarle
Adam Earle commented 2022-12-23 06:05:07 +01:00
Copy Link

I have to agree as an animator. Onion skinning is something that is accessed a lot a lot, so constantly menu diving for this feature doesn't really make sense.
You want to also consider Freezframe (pin frames/ snapshots) and shift & traceas well.

Kinda a feature you don't really want to mess up and get wrong.
Take a look at how OpenToonz does it. It is honestly one of the best systems I have ever used, just because of how great it works and how simple it is.

Also, I would be tempted say that onion skinning is keyframe handling the viewport is just displaying the outcome.

No point in reinventing the camera when every animation system has a camera. The same idea applies here as well. Blender is just in a better position to hear from the masses.

In #102217#1464235, @Nika-Kutsniashvili wrote:
Hello. I want to give user feedback if that's ok. I like the GUI designs presented and personally, I'll use the N menu one, but I have a lot of 2D animator friends and thought how would they find the settings for it if they opened up Blender for the first time. I decided to check how grease pencil onion skinning worked but couldn't find it myself. It took me minutes of googling, reading blender doc and youtube videos to finally find where they were. Not only that, but turns out there's no on/off switch. I had to reduce number of skins to 0 to make it go away. Not only is it timewasting practice, but absolutely confusing to anyone opening it for the first time. It's gonna be same for the 3D if beginner opens up blender and wants to control ghosts.

image.png

In other softwares I've used there is always on/off switch for onion skinning at either of those places, and since blender already uses those horizontal menu-thingys so well I think it absolutely needs to go there in either of those places. Personally what I would go for would be one button for toggling on/off and next to it arrow icon that opens up same options that are in N menu. Like Show Gizmo/Overlays buttons.

I hope this is helpful. Appreciate all the amazing work you do and can't wait for this feature. Thank you.

I have to agree as an animator. Onion skinning is something that is accessed a lot a lot, so constantly menu diving for this feature doesn't really make sense. You want to also consider **Freezframe** *(pin frames/ snapshots)* and **shift & trace**as well. Kinda a feature you don't really want to mess up and get wrong. Take a look at how OpenToonz does it. It is honestly one of the best systems I have ever used, just because of how great it works and how simple it is. Also, I would be tempted say that **onion skinning** is **keyframe handling** the viewport is just displaying the outcome. No point in reinventing the camera when every animation system has a camera. The same idea applies here as well. Blender is just in a better position to hear from the masses. > In #102217#1464235, @Nika-Kutsniashvili wrote: > Hello. I want to give user feedback if that's ok. I like the GUI designs presented and personally, I'll use the N menu one, but I have a lot of 2D animator friends and thought how would they find the settings for it if they opened up Blender for the first time. I decided to check how grease pencil onion skinning worked but couldn't find it myself. It took me minutes of googling, reading blender doc and youtube videos to finally find where they were. Not only that, but turns out there's no on/off switch. I had to reduce number of skins to 0 to make it go away. Not only is it timewasting practice, but absolutely confusing to anyone opening it for the first time. It's gonna be same for the 3D if beginner opens up blender and wants to control ghosts. > > ![image.png](https://archive.blender.org/developer/F14082360/image.png) > > In other softwares I've used there is always on/off switch for onion skinning at either of those places, and since blender already uses those horizontal menu-thingys so well I think it absolutely needs to go there in either of those places. Personally what I would go for would be one button for toggling on/off and next to it arrow icon that opens up same options that are in N menu. Like Show Gizmo/Overlays buttons. > > I hope this is helpful. Appreciate all the amazing work you do and can't wait for this feature. Thank you.
Philipp Oeser removed the
Interest
Animation & Rigging
 label 2023-02-09 14:34:44 +01:00
Christoph Lendenfeld commented 2023-06-15 11:25:31 +02:00
Author
Member
Copy Link

based on your suggestion and my experiments in #107641
I have come up with this design

based on your suggestion and my experiments in [#107641](https://projects.blender.org/blender/blender/pulls/107641) I have come up with this design
onion_skin_timeline.jpg
105 KiB
onion_skin_timeline.jpg
👍 1
Nika Kutsniashvili commented 2023-06-15 12:46:17 +02:00
Contributor
Copy Link

Great job. What I would reconsider is this:

  1. First of all, colours. Hopefully they can be set in theme, but Red is past, Green is future, that's just how its in every software, how traffic signs work even, its just embeded in society right now. I would confuse this in 3D viewport all the time.

  2. I like shortcuts for dragging and pinning, but looking at it it looks like you can't change it, design doesn't tell you about that ability, because it looks like cached data. I would add brackets at the end and start of past/future, so that it communicates with user the ability, and if its draggable by mouse its just perfect design in my opinion.

  3. I think design should be unified with Grease Pencil somehow, drawing in the timeline, shortcuts, pinning and colours should be same for consistency.

  4. I think dashes should always merge, so that its easier to see. Just red lines below frame numbers looks more like an error message.

Great job. What I would reconsider is this: 1. First of all, colours. Hopefully they can be set in theme, but Red is past, Green is future, that's just how its in every software, how traffic signs work even, its just embeded in society right now. I would confuse this in 3D viewport all the time. 2. I like shortcuts for dragging and pinning, but looking at it it looks like you can't change it, design doesn't tell you about that ability, because it looks like cached data. I would add brackets at the end and start of past/future, so that it communicates with user the ability, and if its draggable by mouse its just perfect design in my opinion. 3. I think design should be unified with Grease Pencil somehow, drawing in the timeline, shortcuts, pinning and colours should be same for consistency. 4. I think dashes should always merge, so that its easier to see. Just red lines below frame numbers looks more like an error message.
Christoph Lendenfeld commented 2023-06-15 13:03:20 +02:00
Author
Member
Copy Link
  1. yes colors would be in user prefs and which colors to chose is not fixed, I am totally open to changing it
  2. The issue with brackets is that they only communicate a range up to a certain frame. However ghosts can be on e.g. 2, 4, 6 frames away from the cursor. That's why I went with dashes. But I agree that ideally it would be draggable by mouse somehow. The shortcut is a bit hidden
  3. yes totally agreed
  4. Not sure about always merging the dashes. There needs to be a way to communicate where the ghost starts and ends
1. yes colors would be in user prefs and which colors to chose is not fixed, I am totally open to changing it 2. The issue with brackets is that they only communicate a range up to a certain frame. However ghosts can be on e.g. 2, 4, 6 frames away from the cursor. That's why I went with dashes. But I agree that ideally it would be draggable by mouse somehow. The shortcut is a bit hidden 3. yes totally agreed 4. Not sure about always merging the dashes. There needs to be a way to communicate where the ghost starts and ends
Nika Kutsniashvili commented 2023-06-15 14:22:04 +02:00
Contributor
Copy Link

If dashes can't be merged by default then they need to be longer I think, so that they're easier to see, especially when you're zoomed in. Right now they're too short and leave too much negative space around them. Something like this

image

If dashes can't be merged by default then they need to be longer I think, so that they're easier to see, especially when you're zoomed in. Right now they're too short and leave too much negative space around them. Something like this ![image](/attachments/c9d6e61e-9f76-4181-aa4d-fd58b524db47)
image.png
24 KiB
Christoph Lendenfeld commented 2023-06-15 14:40:16 +02:00
Author
Member
Copy Link

yeah why not, the dash can fill the whole space of its frame as long as there is room for it

yeah why not, the dash can fill the whole space of its frame as long as there is room for it
Brad Clark commented 2023-06-15 18:24:39 +02:00
Member
Copy Link

Can the dashes use the new GP "frame can have a length option? image

Can the dashes use the new GP "frame can have a length option? ![image](/attachments/8c35382d-648a-43c5-a7ea-325b2b5bd0a8)
image.png
24 KiB
👍 1
Christoph Lendenfeld commented 2023-06-16 08:55:53 +02:00
Author
Member
Copy Link

hmm I don't see how I could make that work between 3D and GP
because my idea was that you specify on the scene which frames are ghosted, and the frame might hold GP and regular keyframe data or none at all

hmm I don't see how I could make that work between 3D and GP because my idea was that you specify on the scene which frames are ghosted, and the frame might hold GP and regular keyframe data or none at all
YimingWu commented 2023-06-16 09:11:53 +02:00
Member
Copy Link

I'll keep an eye on this, seems interesting.

I'll keep an eye on this, seems interesting.
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
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, https://wiki.blender.org/wiki/Process/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
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
9 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#102217
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?