Keyframe returned by keyframe_points.insert() gets ruined by any other call to keyframe_points.insert() #83044

New Issue

burger@wiredworks.com · 2020-11-26T11:17:32+01:00

2020-11-26 11:17:32 +01:00

System Information
Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: Quadro K2000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 385.69

Blender Version
Broken: version: 2.83.4, branch: master, commit date: 2020-08-05 06:00, hash: c113af8288
Worked: (newest version of Blender that worked as expected)

Short description of error
Keyframe_points handles not set

Exact steps for others to reproduce the error

Default startup with Cube

A simple script not setting the keyframe_points handles to the specified points

import bpy

Dataobject = bpy.data.objects['Cube']

Dataobject['Pos'] = 0
fcurve = Dataobject.driver_add('["Pos"]')
- THX to Philipp Oeser (lichtwerk)
- to edit the driver fcurve with keyframes, you'll have to remove the fmodifier
try:
    fcurve.modifiers.remove(fcurve.modifiers[0])
except IndexError:
     pass
PointA = fcurve.keyframe_points.insert(0,0)
PointB = fcurve.keyframe_points.insert(1,1)
PointC = fcurve.keyframe_points.insert(2,1)
PointD = fcurve.keyframe_points.insert(3,0)

PointA.handle_left  = ( 0 , 0)
PointA.handle_right = ( 0 , 0)
PointB.handle_left  = ( 1 , 1)
PointB.handle_right = ( 1 , 1)
PointC.handle_left  = ( 2 , 1)
PointC.handle_right = ( 2 , 1)
PointD.handle_left  = ( 3 , 0)
PointD.handle_right = ( 3 , 0)

Note :The handles of the last point are correct

A simple script setting them to their correct points

import bpy

Dataobject = bpy.data.objects['Cube']

Dataobject['Pos'] = 0
fcurve = Dataobject.driver_add('["Pos"]')
- THX to Philipp Oeser (lichtwerk)
- to edit the driver fcurve with keyframes, you'll have to remove the fmodifier
try:
    fcurve.modifiers.remove(fcurve.modifiers[0])
except IndexError:
     pass
PointA = fcurve.keyframe_points.insert(0,0)
PointB = fcurve.keyframe_points.insert(1,1)
PointC = fcurve.keyframe_points.insert(2,1)
PointD = fcurve.keyframe_points.insert(3,0)

fcurve.keyframe_points[0].handle_left  = ( 0 , 0)
fcurve.keyframe_points[0].handle_right = ( 0 , 0)
fcurve.keyframe_points[1].handle_left  = ( 1 , 1)
fcurve.keyframe_points[1].handle_right = ( 1 , 1)
fcurve.keyframe_points[2].handle_left  = ( 2 , 1)
fcurve.keyframe_points[2].handle_right = ( 2 , 1)
fcurve.keyframe_points[3].handle_left  = ( 3 , 0)
fcurve.keyframe_points[3].handle_right = ( 3 , 0)

the problem is that each time you insert a new keyframe, you are actually ruining all previous return values of keyframe_points.insert
- the reason for this is that insert_bezt_fcurve will actually realloc the whole fcu->bezt [which holds your "keyframes"], see [here ]] and [ https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$453 | here

To check, just compare the memory addresses:

print(PointA, fcurve.keyframe_points[0])
print(PointB, fcurve.keyframe_points[1])
print(PointC, fcurve.keyframe_points[2])
print(PointD, fcurve.keyframe_points[3])

**System Information** Operating system: Windows-7-6.1.7601-SP1 64 Bits Graphics card: Quadro K2000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 385.69 **Blender Version** Broken: version: 2.83.4, branch: master, commit date: 2020-08-05 06:00, hash: `c113af8288` Worked: (newest version of Blender that worked as expected) **Short description of error** Keyframe_points handles not set **Exact steps for others to reproduce the error** Default startup with Cube A simple script not setting the keyframe_points handles to the specified points ``` import bpy Dataobject = bpy.data.objects['Cube'] Dataobject['Pos'] = 0 fcurve = Dataobject.driver_add('["Pos"]') - THX to Philipp Oeser (lichtwerk) - to edit the driver fcurve with keyframes, you'll have to remove the fmodifier try: fcurve.modifiers.remove(fcurve.modifiers[0]) except IndexError: pass PointA = fcurve.keyframe_points.insert(0,0) PointB = fcurve.keyframe_points.insert(1,1) PointC = fcurve.keyframe_points.insert(2,1) PointD = fcurve.keyframe_points.insert(3,0) PointA.handle_left = ( 0 , 0) PointA.handle_right = ( 0 , 0) PointB.handle_left = ( 1 , 1) PointB.handle_right = ( 1 , 1) PointC.handle_left = ( 2 , 1) PointC.handle_right = ( 2 , 1) PointD.handle_left = ( 3 , 0) PointD.handle_right = ( 3 , 0) ``` ![Keyframe_points.png](https://archive.blender.org/developer/F9379650/Keyframe_points.png) Note :The handles of the last point are correct A simple script setting them to their correct points ``` import bpy Dataobject = bpy.data.objects['Cube'] Dataobject['Pos'] = 0 fcurve = Dataobject.driver_add('["Pos"]') - THX to Philipp Oeser (lichtwerk) - to edit the driver fcurve with keyframes, you'll have to remove the fmodifier try: fcurve.modifiers.remove(fcurve.modifiers[0]) except IndexError: pass PointA = fcurve.keyframe_points.insert(0,0) PointB = fcurve.keyframe_points.insert(1,1) PointC = fcurve.keyframe_points.insert(2,1) PointD = fcurve.keyframe_points.insert(3,0) fcurve.keyframe_points[0].handle_left = ( 0 , 0) fcurve.keyframe_points[0].handle_right = ( 0 , 0) fcurve.keyframe_points[1].handle_left = ( 1 , 1) fcurve.keyframe_points[1].handle_right = ( 1 , 1) fcurve.keyframe_points[2].handle_left = ( 2 , 1) fcurve.keyframe_points[2].handle_right = ( 2 , 1) fcurve.keyframe_points[3].handle_left = ( 3 , 0) fcurve.keyframe_points[3].handle_right = ( 3 , 0) ``` ![keyframe1.png](https://archive.blender.org/developer/F9379695/keyframe1.png) - the problem is that each time you insert a new keyframe, you are actually ruining all previous return values of `keyframe_points.insert` - the reason for this is that `insert_bezt_fcurve` will actually realloc the whole `fcu->bezt` [which holds your "keyframes"], see [here ]] and [[ https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$453 | here ](https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$436) To check, just compare the memory addresses: ``` print(PointA, fcurve.keyframe_points[0]) print(PointB, fcurve.keyframe_points[1]) print(PointC, fcurve.keyframe_points[2]) print(PointD, fcurve.keyframe_points[3]) ```

burger@wiredworks.com commented

2020-11-26 11:17:32 +01:00

Added subscriber: @martburg

burger@wiredworks.com commented

2020-11-26 11:26:56 +01:00

it get' even better when more points are added the already correct handles get overwritten

import bpy

Dataobject = bpy.data.objects['Cube']

Dataobject['Pos'] = 0
fcurve = Dataobject.driver_add('["Pos"]')
- THX to Philipp Oeser (lichtwerk)
- to edit the driver fcurve with keyframes, you'll have to remove the fmodifier
try:
    fcurve.modifiers.remove(fcurve.modifiers[0])
except IndexError:
     pass
PointA = fcurve.keyframe_points.insert(0,0)
PointB = fcurve.keyframe_points.insert(1,1)
PointC = fcurve.keyframe_points.insert(2,1)
PointD = fcurve.keyframe_points.insert(3,0)

fcurve.keyframe_points[0].handle_left  = ( 0 , 0)
fcurve.keyframe_points[0].handle_right = ( 0 , 0)
fcurve.keyframe_points[1].handle_left  = ( 1 , 1)
fcurve.keyframe_points[1].handle_right = ( 1 , 1)
fcurve.keyframe_points[2].handle_left  = ( 2 , 1)
fcurve.keyframe_points[2].handle_right = ( 2 , 1)
fcurve.keyframe_points[3].handle_left  = ( 3 , 0)
fcurve.keyframe_points[3].handle_right = ( 3 , 0)
 
PointE = fcurve.keyframe_points.insert(0.5,0)
PointF = fcurve.keyframe_points.insert(1.5,1)
PointG = fcurve.keyframe_points.insert(2.5,1)
PointH = fcurve.keyframe_points.insert(3.5,0)

it get' even better when more points are added the already correct handles get overwritten ``` import bpy Dataobject = bpy.data.objects['Cube'] Dataobject['Pos'] = 0 fcurve = Dataobject.driver_add('["Pos"]') - THX to Philipp Oeser (lichtwerk) - to edit the driver fcurve with keyframes, you'll have to remove the fmodifier try: fcurve.modifiers.remove(fcurve.modifiers[0]) except IndexError: pass PointA = fcurve.keyframe_points.insert(0,0) PointB = fcurve.keyframe_points.insert(1,1) PointC = fcurve.keyframe_points.insert(2,1) PointD = fcurve.keyframe_points.insert(3,0) fcurve.keyframe_points[0].handle_left = ( 0 , 0) fcurve.keyframe_points[0].handle_right = ( 0 , 0) fcurve.keyframe_points[1].handle_left = ( 1 , 1) fcurve.keyframe_points[1].handle_right = ( 1 , 1) fcurve.keyframe_points[2].handle_left = ( 2 , 1) fcurve.keyframe_points[2].handle_right = ( 2 , 1) fcurve.keyframe_points[3].handle_left = ( 3 , 0) fcurve.keyframe_points[3].handle_right = ( 3 , 0) PointE = fcurve.keyframe_points.insert(0.5,0) PointF = fcurve.keyframe_points.insert(1.5,1) PointG = fcurve.keyframe_points.insert(2.5,1) PointH = fcurve.keyframe_points.insert(3.5,0) ``` ![keyframe2.png](https://archive.blender.org/developer/F9379763/keyframe2.png)

Philipp Oeser commented

2020-11-26 11:34:18 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2020-11-26 11:34:18 +01:00

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

Philipp Oeser commented

2020-11-26 11:34:18 +01:00

Will check

Philipp Oeser commented

2020-11-26 13:56:20 +01:00

Not sure how this is supposed to work correctly, but here are my findings:

you might be lucky, it might work with the last Keyframe you are manipulating
the problem is that each time you insert a new keyframe, you are actually ruining all previous return values of keyframe_points.insert
- the reason for this is that insert_bezt_fcurve will actually realloc the whole fcu->bezt [which holds your "keyframes"], see [here ]] and [ https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$453 | here

To check, just compare the memory addresses:

print(PointA, fcurve.keyframe_points[0])
print(PointB, fcurve.keyframe_points[1])
print(PointC, fcurve.keyframe_points[2])
print(PointD, fcurve.keyframe_points[3])

Now, one might come to the conclusion that the return value is still usable for the time no other keyframe has been inserted, but this fails as well (I havent tracked down this further):

import bpy

Dataobject = bpy.data.objects['Cube']

Dataobject['Pos'] = 0
fcurve = Dataobject.driver_add('["Pos"]')
- THX to Philipp Oeser (lichtwerk)
- to edit the driver fcurve with keyframes, you'll have to remove the fmodifier
try:
    fcurve.modifiers.remove(fcurve.modifiers[0])
except IndexError:
     pass
PointA = fcurve.keyframe_points.insert(0,0)
PointA.handle_left  = ( 0 , 0)
PointA.handle_right = ( 0 , 0)
fcurve.update()

PointB = fcurve.keyframe_points.insert(1,1)
PointB.handle_left  = ( 1 , 1)
PointB.handle_right = ( 1 , 1)
fcurve.update()

PointC = fcurve.keyframe_points.insert(2,1)
PointC.handle_left  = ( 2 , 1)
PointC.handle_right = ( 2 , 1)
fcurve.update()

PointD = fcurve.keyframe_points.insert(3,0)
PointD.handle_left  = ( 3 , 0) #these work
PointD.handle_right = ( 3 , 0) #these work
fcurve.update()

So to me it looks like the returned Keyframe of keyframe_points.insert gets broken by every other call to keyframe_points.insert.
And the way inserting keyframes happens internally, there is also no easy way out.

Not sure how this is supposed to work correctly, but here are my findings: - you might be lucky, it might work with the last Keyframe you are manipulating - the problem is that each time you insert a new keyframe, you are actually ruining all previous return values of `keyframe_points.insert` - the reason for this is that `insert_bezt_fcurve` will actually realloc the whole `fcu->bezt` [which holds your "keyframes"], see [here ]] and [[ https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$453 | here ](https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$436) To check, just compare the memory addresses: ``` print(PointA, fcurve.keyframe_points[0]) print(PointB, fcurve.keyframe_points[1]) print(PointC, fcurve.keyframe_points[2]) print(PointD, fcurve.keyframe_points[3]) ``` Now, one might come to the conclusion that the return value is still usable for the time no other keyframe has been inserted, but this fails as well (I havent tracked down this further): ``` import bpy Dataobject = bpy.data.objects['Cube'] Dataobject['Pos'] = 0 fcurve = Dataobject.driver_add('["Pos"]') - THX to Philipp Oeser (lichtwerk) - to edit the driver fcurve with keyframes, you'll have to remove the fmodifier try: fcurve.modifiers.remove(fcurve.modifiers[0]) except IndexError: pass PointA = fcurve.keyframe_points.insert(0,0) PointA.handle_left = ( 0 , 0) PointA.handle_right = ( 0 , 0) fcurve.update() PointB = fcurve.keyframe_points.insert(1,1) PointB.handle_left = ( 1 , 1) PointB.handle_right = ( 1 , 1) fcurve.update() PointC = fcurve.keyframe_points.insert(2,1) PointC.handle_left = ( 2 , 1) PointC.handle_right = ( 2 , 1) fcurve.update() PointD = fcurve.keyframe_points.insert(3,0) PointD.handle_left = ( 3 , 0) #these work PointD.handle_right = ( 3 , 0) #these work fcurve.update() ``` So to me it looks like the returned Keyframe of `keyframe_points.insert` gets broken by every other call to `keyframe_points.insert`. And the way inserting keyframes happens internally, there is also no easy way out.

Philipp Oeser changed title from ~~Keyframe_points handles not set~~ to Keyframe returned by keyframe_points.insert() gets ruined by any other call to keyframe_points.insert()

2020-11-26 13:59:11 +01:00

Philipp Oeser commented

2020-11-26 14:07:14 +01:00

I think this also answers the point raised in #82227 (Inconsistent Behavior T81299)

In #82227#1051121, @martburg wrote:
...
and the inconsistency is not that behavior but the loss of the reference to the points
    self.InK.co = (0,0)
    self.Mid.co = (100,10)
    self.Out.co = (200,0)
declared in def execute but in def modal those points have to be addressed as
        self.cue.keyframe_points- [x].co = (0,0)
        self.cue.keyframe_points- [x].co = (100,10)
        self.cue.keyframe_points- [x].co = (200,0)

I think this also answers the point raised in #82227 (Inconsistent Behavior T81299) > In #82227#1051121, @martburg wrote: > ... > and the inconsistency is not **that** behavior but the loss of the reference to the points > > self.InK.co = (0,0) > self.Mid.co = (100,10) > self.Out.co = (200,0) > > declared in `def execute` but in `def modal` those points have to be addressed as > > self.cue.keyframe_points- [x].co = (0,0) > self.cue.keyframe_points- [x].co = (100,10) > self.cue.keyframe_points- [x].co = (200,0)

burger@wiredworks.com commented

2020-11-26 14:09:42 +01:00

Yes, it does ---- you were faster

THX
Martin

Yes, it does ---- you were faster THX Martin

Sybren A. Stüvel commented

2020-11-26 14:29:07 +01:00

Added subscriber: @dr.sybren

Sybren A. Stüvel commented

2020-11-26 14:29:07 +01:00

fcurve.keyframe_points.insert() sorts the keyframes to ensure they're stored in order of timestamp. This means that Python objects created before the call are not necessarily valid after that call. Pass options={'FAST'} to prevent this, and call fcurve.update() after the work on the curve is done.

`fcurve.keyframe_points.insert()` sorts the keyframes to ensure they're stored in order of timestamp. This means that Python objects created before the call are not necessarily valid after that call. Pass `options={'FAST'}` to prevent this, and call `fcurve.update()` after the work on the curve is done.

Philipp Oeser commented

2020-11-26 14:37:56 +01:00

@dr.sybren: thx looking into this.

Unfortunately, this doesnt seem to work...
#83044.blend

Am I doing something wrong?

@dr.sybren: thx looking into this. Unfortunately, this doesnt seem to work... [#83044.blend](https://archive.blender.org/developer/F9381023/T83044.blend) Am I doing something wrong?

Philipp Oeser commented

2020-11-27 09:21:25 +01:00

In #83044#1061973, @lichtwerk wrote:

the problem is that each time you insert a new keyframe, you are actually ruining all previous return values of keyframe_points.insert
-- the reason for this is that insert_bezt_fcurve will actually realloc the whole fcu->bezt [which holds your "keyframes"], see [here ]] and [ https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$453 | here

To check, just compare the memory addresses:
print(PointA, fcurve.keyframe_points[0])
print(PointB, fcurve.keyframe_points[1])
print(PointC, fcurve.keyframe_points[2])
print(PointD, fcurve.keyframe_points[3])

Looks like all of this is still true -- even for options={'FAST'}

<bpy_struct, Keyframe at 0x7fbaee09e9f8> <bpy_struct, Keyframe at 0x7fbafafa9208>
<bpy_struct, Keyframe at 0x7fbafa78bbf0> <bpy_struct, Keyframe at 0x7fbafafa9250>
<bpy_struct, Keyframe at 0x7fbafb2aad38> <bpy_struct, Keyframe at 0x7fbafafa9298>
<bpy_struct, Keyframe at 0x7fbafafa92e0> <bpy_struct, Keyframe at 0x7fbafafa92e0>

For the last call, address is the same, previous ones are ruined.

> In #83044#1061973, @lichtwerk wrote: > - the problem is that each time you insert a new keyframe, you are actually ruining all previous return values of `keyframe_points.insert` > -- the reason for this is that `insert_bezt_fcurve` will actually realloc the whole `fcu->bezt` [which holds your "keyframes"], see [here ]] and [[ https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$453 | here ](https:*developer.blender.org/diffusion/B/browse/master/source/blender/editors/animation/keyframing.c$436) > > To check, just compare the memory addresses: > > ``` > print(PointA, fcurve.keyframe_points[0]) > print(PointB, fcurve.keyframe_points[1]) > print(PointC, fcurve.keyframe_points[2]) > print(PointD, fcurve.keyframe_points[3]) > ``` Looks like all of this is still true -- even for `options={'FAST'}` ``` <bpy_struct, Keyframe at 0x7fbaee09e9f8> <bpy_struct, Keyframe at 0x7fbafafa9208> <bpy_struct, Keyframe at 0x7fbafa78bbf0> <bpy_struct, Keyframe at 0x7fbafafa9250> <bpy_struct, Keyframe at 0x7fbafb2aad38> <bpy_struct, Keyframe at 0x7fbafafa9298> <bpy_struct, Keyframe at 0x7fbafafa92e0> <bpy_struct, Keyframe at 0x7fbafafa92e0> ``` For the last call, address is the same, previous ones are ruined.

Sybren A. Stüvel commented

2020-11-27 12:30:13 +01:00

Changed status from 'Confirmed' to: 'Archived'

Sybren A. Stüvel closed this issue

2020-11-27 12:30:13 +01:00

Sybren A. Stüvel commented

2020-11-27 12:30:13 +01:00

Ah yes, I confused two things. options={'FAST'} skips the calculation of automatic handles. Reordering of the keyframes always happens.

I'm closing this as invalid, as this is not a bug but simply how Blender works. This is similar to the array re-allocation described in the "Gochas" section of the Python API documentation.

Ah yes, I confused two things. `options={'FAST'}` skips the calculation of automatic handles. Reordering of the keyframes always happens. I'm closing this as invalid, as this is not a bug but simply how Blender works. This is similar to the [array re-allocation described in the "Gochas" section of the Python API documentation](https://docs.blender.org/api/master/info_gotcha.html#array-re-allocation).

Philipp Oeser commented

2020-11-27 12:41:52 +01:00

In #83044#1063064, @dr.sybren wrote:
This is similar to the array re-allocation described in the "Gochas" section of the Python API documentation.

This is good to know!

> In #83044#1063064, @dr.sybren wrote: > This is similar to the [array re-allocation described in the "Gochas" section of the Python API documentation](https://docs.blender.org/api/master/info_gotcha.html#array-re-allocation). This is good to know!

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Keyframe returned by keyframe_points.insert() gets ruined by any other call to keyframe_points.insert() #83044