Grease Pencil: Automated Interpolation
Summary : Introduce an automatic type of interpolation, where every pair of keyframes marked for "automatic interpolation" will have their inbetweens automatically recalculated by Blender as soon as any of either keyframe is modified.
The problem with interpolation, while very powerful, is that it is still manually activated by the user. This means that if one modifies a keyframe that is subject to interpolation with another key before or after, the interpolation does not take the modification into account. The user has to delete all the in-betweens and re-run the interpolation process. With complex animations, where there are likely several layers, each with dozens of keys, even the slightest tweak might require to modify several keys, and thus re-do twice as many interpolations. A tremendous waste of time.
Considering that interpolation is in itself already algorithmic, that Blender can tell when something has been modified, and that there are plenty of marking features in the dope sheet (viz. "Keyframe Type", "Handle Type", "Interpolation Mode"), it shouldn't be much of a challenge to implement a feature where Blender would recalculate frames marked for automated interpolation.
There might be a few difficult special cases, such as the user adding a shape to a keyframe and not having a corresponding one in another key , but these could be looked over in favor of the many situations where automated interpolation would speed up workflow. Key modification aside, it would allow for much more experimentation with timing , since the system could also automatically recalculate interpolation when a keyframe is moved along the timeline - add inbetweens if the key is moved away, remove some if it is moved closer to the other key.
4 Comments
Greetings, I put together semi automated patch for this: projects.blender.org/blender/blender/pulls/159378
I have half a python framework for some of this already. Building it in C could add some real capability.
I would suggest submitting this idea here: blender.chat/channel/grease-pencil-module
I will be happy to support you in there as well. Also ask for people on Twitter to support the idea and even point to the proposal. This way more people can show their support for the idea.
If this makes it into Blender 3 it would be amazing. To be honest, though I can't see it happening. That doesn't mean try though.
Also try to refine how you really see this happening. The more code that is already in Blender that can be manipulated to achieve this behavior is always favorable. The other thing is, make it so simple the developers feel like it won't take much to implement.
Great idea. Good luck.
You mean Like this ?
* @ammusionist * I mean an automated version of that - in the sense that "interpolate sequence" will be reapplied automatically by Blender between a key A and key B whenever I modify A or/and B.
Unless I missed some crucial feature that already does what I mean, the current in-betweens created by "interpolate sequence" are effectively final and behave like any other hand-drawn frame after their creation by the algorithm. If I modify a key A or B after using "interpolate sequence" between them, the in-betweens will not reflect that change. I need to delete all the in-betweens and re-run "interpolate sequence" to get a correct interpolation.