Support using Graph Editor F-Curves as procedural interpolation data via Python
I am speaking from a user perspective rather than an implementation or API design point of view.
I really enjoy a workflow where I can author motion directly in the Graph Editor using F-Curves, and then reuse those curves procedurally as interpolation curves.
In add-ons like Animation Nodes, it was previously possible to use user-created F-Curves (including custom property curves) as interpolation inputs, allowing timing, delay, and duration to be adjusted later without re-authoring the animation. This workflow is extremely powerful and flexible for procedural animation.
In Blender 5.0, changes to the Action / F-Curve API make it difficult for add-ons such as Animation Nodes to access and evaluate user-authored F-Curves from Python. As a result, this curve-driven interpolation workflow is no longer easily achievable.
I understand that internal API changes are sometimes necessary, but it would be great to have a supported or documented way to enumerate and evaluate user-created F-Curves from Python again in Blender 5.x.
Being able to reuse Graph Editor curves as procedural interpolation
data is something I rely on heavily, and I would be very happy to see
this kind of workflow supported going forward.
4 Comments
I am not sure if the issue is just that Animation Nodes needs to be updated to use the correct API functions. The API has changed, but the functionality is still there.
Thank you for the clarification.
I may not have explained my situation clearly, so I’d like to clarify from a user perspective.
Previously, in Blender versions before 5.0, I was able to retrieve F-Curves inside Animation Nodes and use them directly for interpolation. This allowed me to author the curve in the Graph Editor and then adjust timing or duration later, which was a very comfortable workflow for me.
In Blender 5.0, this no longer seems to work: Animation Nodes can no longer retrieve the F-Curve, so interpolation using an F-Curve is not possible in the same way as before. Interpolation using other curve-based methods is possible, but using actual F-Curves feels much more intuitive and flexible in practice.
I’m not sure whether this is purely an issue of Animation Nodes needing to be updated to the new API, or if there is a missing or undocumented recommended way to access F-Curves from Python now. I’m not a developer myself, so this request is based purely on my user experience and workflow.
I also tried to look into this issue myself, and it seems possible that it is related to API changes in Blender 5.0, although I may be mistaken. Regardless of the underlying cause, this workflow used to be possible and very useful for me, and I would be happy if something similar could be supported again.
See the addon repository: github.com/JacquesLucke/animation_nodes/issues/1999
Thank you for the link!
I wasn’t aware of that issue. I’ll follow #1999 and add my details there, since my main concern is that the previous workflow (using user-authored F-Curves as interpolation curves in Animation Nodes) no longer works in Blender 5.0.
From a user perspective, I’d be very happy if this workflow can be restored, whether that requires an Animation Nodes update or clearer guidance/documentation on the new API access patterns.
Thanks again for pointing me to the right place.