Graph Editor - Smooth Keys function not working correctly #39324

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Ignatz · 2014-03-21T14:20:23+01:00

Ignatz commented

2014-03-21 14:20:23 +01:00

Windows 7 Pro 64-bit
Intel Core i7-4770K CPU @ 3.50GHz
ASUS nVidia GeForce GTX 760 2GB GDDR5 DirectCU Mini

Broken: 2.69 r60995

Broken: 2.70 19e627c

Problem: Smoothing algorithm does not work properly.

When the selected keyframes in the file are subjected to the smoothing algorithm (alt-o) the results are actually much worse (bumpier) than before the algorithm was used.

Yes, I know this appears to be a 'worst case' scenario, since the curve in question has already been hand adjusted to be correct. But this algorithm is basically 'broken' if it makes such a curve worse than when it started.

In point of fact, I have attempted to use this 'smoothing' algorithm several times on real world problem curves and find that the results are so bad as to make it more trouble than it is worth. It is simpler to save time and adjust my curves by hand.

Such a function is needed within the graph editor, but the current results would suggest that this algorithm is really due for a re-write.

See attached blend file.

Graph_editor_-_smooth_keys_problem.blend

Windows 7 Pro 64-bit Intel Core i7-4770K CPU @ 3.50GHz ASUS nVidia GeForce GTX 760 2GB GDDR5 DirectCU Mini Broken: 2.69 r60995 Broken: 2.70 19e627c Problem: Smoothing algorithm does not work properly. When the selected keyframes in the file are subjected to the smoothing algorithm (alt-o) the results are actually much worse (bumpier) than before the algorithm was used. Yes, I know this appears to be a 'worst case' scenario, since the curve in question has already been hand adjusted to be correct. But this algorithm is basically 'broken' if it makes such a curve worse than when it started. In point of fact, I have attempted to use this 'smoothing' algorithm several times on real world problem curves and find that the results are so bad as to make it more trouble than it is worth. It is simpler to save time and adjust my curves by hand. Such a function is needed within the graph editor, but the current results would suggest that this algorithm is really due for a re-write. ![smoothing_problem.jpg](https://archive.blender.org/developer/F82084/smoothing_problem.jpg) See attached blend file. [Graph_editor_-_smooth_keys_problem.blend](https://archive.blender.org/developer/F82086/Graph_editor_-_smooth_keys_problem.blend)

Ignatz commented

2014-03-21 14:20:23 +01:00

Changed status to: 'Open'

Ignatz commented

2014-03-21 14:20:23 +01:00

Added subscriber: @ignatz

Bastien Montagne commented

2014-03-22 12:38:47 +01:00

Added subscriber: @mont29

Joshua Leung was assigned by Bastien Montagne

2014-03-22 12:40:50 +01:00

Bastien Montagne commented

2014-03-22 12:40:50 +01:00

I’m not quite sure this is really a bug, as far as I know this tool is designed to ease curves with many keyframes, not to be applied on such one as in your example. We more than likely would use better algo, but this does not make it a bug imho.

Will let Joshua decide, anyway! :)

I’m not quite sure this is really a bug, as far as I know this tool is designed to ease curves with many keyframes, not to be applied on such one as in your example. We more than likely would use better algo, but this does not make it a bug imho. Will let Joshua decide, anyway! :)

Ignatz commented

2014-03-22 13:17:05 +01:00

@mont29 - As I pointed out in the write-up, I used this as a 'worst case' scenario in order to demonstrate that the algorithm doesn't have the basic 'smarts' to figure out that a curve is already smooth enough. In other real world examples of my own work where the curves are not already smooth it does much worse... seldom actually doing any real 'smoothing' in a way that would be helpful.

Joshua Leung commented

2014-03-28 00:08:40 +01:00

As @mont29 said, the algorithm in use was designed for use with relatively dense FCurves instead of for curves like this.

Joshua Leung was unassigned by Sybren A. Stüvel

2020-11-09 18:37:25 +01:00

Christoph Lendenfeld commented

2020-11-15 22:23:39 +01:00

Added subscriber: @ChrisLend

Christoph Lendenfeld self-assigned this 2020-11-15 22:23:39 +01:00

Christoph Lendenfeld commented

2020-11-15 22:23:39 +01:00

I implemented a solution to this in D9477

I implemented a solution to this in [D9477](https://archive.blender.org/developer/D9477)

Philipp Oeser removed the

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Graph Editor - Smooth Keys function not working correctly #39324