"Stepped" F-curve modifier does not work as expected when stacked after other modifiers #39291

New Issue

Sam Brubaker · 2014-03-20T19:07:06+01:00

Sam Brubaker commented

2014-03-20 19:07:06 +01:00

Version: 2.70 official (win 64)

How to reproduce: Open the provided file, or create any F-Curve that uses the "Stepped" modifier as the 2nd or lower modifier in part of a stack.

FCurveModiferFail.blend

Expected behavoir: The F-Curve shown should resemble a sine wave, but flat over every interval of 4 frames. Instead, it looks as though the sine wave function was being carried out afterthe stepped modifier.

The "Stepped" modifier, being last in the stack as shown, does not appear to read the result of the first sine wave modifier. The problem is the same for noise and generator modifiers as well. This makes it problematic if an animator wants to "step" any kind of noise or function in the f-curve.

Here is a screenshot:

Version: 2.70 official (win 64) How to reproduce: Open the provided file, or create any F-Curve that uses the "Stepped" modifier as the 2nd or lower modifier in part of a stack. [FCurveModiferFail.blend](https://archive.blender.org/developer/F81953/FCurveModiferFail.blend) Expected behavoir: The F-Curve shown should resemble a sine wave, but flat over every interval of 4 frames. Instead, it looks as though the sine wave function was being carried out *after*the stepped modifier. The "Stepped" modifier, being last in the stack as shown, does not appear to read the result of the first sine wave modifier. The problem is the same for noise and generator modifiers as well. This makes it problematic if an animator wants to "step" any kind of noise or function in the f-curve. Here is a screenshot: ![FCurveModiferFail.blend.png](https://archive.blender.org/developer/F81955/FCurveModiferFail.blend.png)

Sam Brubaker commented

2014-03-20 19:07:06 +01:00

Changed status to: 'Open'

Sam Brubaker commented

2014-03-20 19:07:06 +01:00

Added subscriber: @rocketman

Joshua Leung was assigned by Bastien Montagne

2014-03-20 20:09:53 +01:00

Bastien Montagne commented

2014-03-20 20:09:53 +01:00

Added subscriber: @mont29

Bastien Montagne commented

2014-03-20 20:09:53 +01:00

Assigning to Joshua since he knows better, but I think this is known limitation of current F-Modifiers system - iirc they take value from org curve, not previous modifier…

Sam Brubaker commented

2014-03-20 20:44:45 +01:00

Thanks, @mont29!

Certain modifiers do work in a stack; the envelope modifier for instance will deform a sine wave function, but a sine wave function can also come after the envelope.

It occurs to me that many modifiers are only additive or multiplicative so stack order is easy to overlook. Also, there's still no buttons for changing the stack order in f-curve modifiers as there are in the mesh modifiers. Perhaps that ought to be fixed as well!

Thanks, @mont29! Certain modifiers do work in a stack; the envelope modifier for instance will deform a sine wave function, but a sine wave function can also come after the envelope. It occurs to me that many modifiers are only additive or multiplicative so stack order is easy to overlook. Also, there's still no buttons for changing the stack order in f-curve modifiers as there are in the mesh modifiers. Perhaps that ought to be fixed as well!

blender-admin commented

2014-03-31 14:54:40 +02:00

This issue was referenced by blender/blender-addons-contrib@b37dc6a8bd

This issue was referenced by blender/blender-addons-contrib@b37dc6a8bd4137ad185a594106b66479add2c1d5

blender-admin commented

2014-03-31 14:54:40 +02:00

This issue was referenced by b37dc6a8bd

This issue was referenced by b37dc6a8bd4137ad185a594106b66479add2c1d5

Joshua Leung commented

2014-03-31 14:56:12 +02:00

Changed status from 'Open' to: 'Resolved'

Joshua Leung closed this issue