Child of constraint target bug #67729

New Issue

Anoca · 2019-07-26T13:01:05+02:00

Anoca commented

2019-07-26 13:01:05 +02:00

Blender Version
Broken: pretty sure till the latest Release Candidate build
Worked: ???

Short description of error
I have seen this bug for quite a long time, and I'm still surprised that it hasn't been noticed by the developers for such long time.
If you try to change the parent target inside of the child of constraint, then clicking "set inverse" will no longer work properly.
Exact steps for others to reproduce the error
Get three objects in your scene.
Here's what you do:

give the first object you created a child of constraint
make the second object as the parent target and set inverse
now change the parent target with the third object

The first object will move in an unknown location as expected so you would have to set inverse again.
Unfortunately tho, the object will go in an unknown location aswell when you click set inverse.
The only way to fix it is by removing the constraint from the first object and make a new one, and this time directly make the third object as the parent target, when you set inverse, the object will go back to its original position just fine.

So what is this bug that confuses the software to do such thing?

This problem applies to bones aswell

**Blender Version** Broken: pretty sure till the latest Release Candidate build Worked: ??? **Short description of error** I have seen this bug for quite a long time, and I'm still surprised that it hasn't been noticed by the developers for such long time. If you try to change the parent target inside of the child of constraint, then clicking "set inverse" will no longer work properly. **Exact steps for others to reproduce the error** Get three objects in your scene. Here's what you do: - give the first object you created a child of constraint - make the second object as the parent target and set inverse - now change the parent target with the third object The first object will move in an unknown location as expected so you would have to set inverse again. Unfortunately tho, the object will go in an unknown location aswell when you click set inverse. The only way to fix it is by removing the constraint from the first object and make a new one, and this time directly make the third object as the parent target, when you set inverse, the object will go back to its original position just fine. So what is this bug that confuses the software to do such thing? This problem applies to bones aswell

Anoca commented

2019-07-26 13:01:05 +02:00

Added subscriber: @Maker26

dark999 commented

2019-07-26 13:50:03 +02:00

Added subscriber: @dark999

dark999 commented

2019-07-26 13:50:03 +02:00

You forgot to upload a simplest possible .blend file to reproduce this issue

Please, update this report following strictly this form https://developer.blender.org/maniphest/task/edit/form/1/

The operating system, main memory size, GPU brand and model, GPU driver version and Blender hash or its build date may be needed by developers to investigate this issue

Check if you hardware and OS work properly outside Blender use and if they have latest update

Next time you can use Help > Report a Bug item and striclty follow this form. Attach a simplest possible .blend file, before you made a bugreport you must search if bug/issue is already reported from others users

You can check here https://www.blender.org/download/requirements/ if your hardware and software meet minimum Blender requirement, if not, you can consider this report as invalid until Blender developers validate this issue

thank you

You forgot to upload a simplest possible .blend file to reproduce this issue Please, update this report following strictly this form https://developer.blender.org/maniphest/task/edit/form/1/ The operating system, main memory size, GPU brand and model, GPU driver version and Blender hash or its build date may be needed by developers to investigate this issue Check if you hardware and OS work properly outside Blender use and if they have latest update Next time you can use Help > Report a Bug item and striclty follow this form. Attach a simplest possible .blend file, before you made a bugreport you must search if bug/issue is already reported from others users You can check here https://www.blender.org/download/requirements/ if your hardware and software meet minimum Blender requirement, if not, you can consider this report as invalid until Blender developers validate this issue thank you

Demeter Dzadik commented

2019-07-26 14:00:53 +02:00

Added subscriber: @Mets

Demeter Dzadik commented

2019-07-26 14:00:53 +02:00

I don't think things like GPU and drivers are likely to be the cause of this issue. And I think they followed the submission form reasonably well. :)

That said, I couldn't reproduce this, so a blend file would definitely be welcome. I recall sometimes having this issue with bones, but even then, hitting Clear Inverse and then Set Inverse fixed it. Here's the .blend where I tried reproducing the issue, but I couldn't:
childof_worksfine.blend

I don't think things like GPU and drivers are likely to be the cause of this issue. And I think they followed the submission form reasonably well. :) That said, I couldn't reproduce this, so a blend file would definitely be welcome. I recall sometimes having this issue with bones, but even then, hitting Clear Inverse and then Set Inverse fixed it. Here's the .blend where I tried reproducing the issue, but I couldn't: [childof_worksfine.blend](https://archive.blender.org/developer/F7629748/childof_worksfine.blend)

dark999 commented

2019-07-26 14:43:38 +02:00

@Mets if blender is open with unsupported hardware and software all kind of error, issues and bugs can be see
how you know user specific of hardware him use?

@Mets if blender is open with unsupported hardware and software all kind of error, issues and bugs can be see how you know user specific of hardware him use?

Anoca commented

2019-07-26 15:10:12 +02:00

Huh, weird, it works fine for me aswell.... for objects only.
but you might have not read the text clearly
"This problem applies to bones aswell"

So, if this doesn't occur with objects, then it should occur with bones instead.

Here is the blend file:
childof With bones.blend

The first target is already set, YOU must change that target bone to the "Second Target" (I named it so you would know which one it is)
I also made a original location for the main bone so you would also know where that bone is supposed to stay normally
Edit: The original location is a bone named "LocationForMainBone"
Edit2: Make sure you are using the latest build. The release candidate build

Huh, weird, it works fine for me aswell.... for objects only. but you might have not read the text clearly "This problem applies to bones aswell" So, if this doesn't occur with objects, then it should occur with bones instead. Here is the blend file: [childof With bones.blend](https://archive.blender.org/developer/F7629825/childof_With_bones.blend) The first target is already set, YOU must change that target bone to the "Second Target" (I named it so you would know which one it is) I also made a original location for the main bone so you would also know where that bone is supposed to stay normally Edit: The original location is a bone named "LocationForMainBone" Edit2: Make sure you are using the latest build. The release candidate build

Demeter Dzadik commented

2019-07-26 15:11:18 +02:00

True, knowing your OS and hardware can't hurt. And I'm all for enforcing stricter rules on bug reports :P But my gut tells me all we need to get to the bottom of this one is a blend file.

Edit: And as I was typing that we got one! Checking...

True, knowing your OS and hardware can't hurt. And I'm all for enforcing stricter rules on bug reports :P But my gut tells me all we need to get to the bottom of this one is a blend file. Edit: And as I was typing that we got one! Checking...

William Reynish commented

2019-07-26 15:12:45 +02:00

Added subscriber: @WilliamReynish

William Reynish commented

2019-07-26 15:12:45 +02:00

Cannot reproduce any issues.

Demeter Dzadik commented

2019-07-26 15:18:49 +02:00

I can see the issue, but it does go away after hitting Clear Inverse.

In the provided blend file, change the Child Of target to "Second target" and hit Set Inverse. It would be expected that the bone goes back to the location of "LocationForMainBone" but it does not. Hitting Clear Inverse then Set Inverse again will work though.

Not sure if a bug, or if you're expected to hit Clear Inverse by design for it to go back to its original place. Seems odd to me for sure.

I can see the issue, but it does go away after hitting Clear Inverse. In the provided blend file, change the Child Of target to "Second target" and hit Set Inverse. It would be expected that the bone goes back to the location of "LocationForMainBone" but it does not. Hitting Clear Inverse then Set Inverse again will work though. Not sure if a bug, or if you're expected to hit Clear Inverse by design for it to go back to its original place. Seems odd to me for sure.

dark999 commented

2019-07-26 15:27:52 +02:00

@Maker26 You forgot to update this report following Strictly this form https://developer.blender.org/maniphest/task/edit/form/1/ as already request

@Maker26 You forgot to update this report following **Strictly** this form https://developer.blender.org/maniphest/task/edit/form/1/ as already request

Anoca commented

2019-07-26 15:48:12 +02:00

So hitting "Clear Inverse" first and then "Set Inverse" would fix it. Alright, this should do the job.

This means that the bug has been solved and this topic is closed as solved :D

So hitting "Clear Inverse" first and then "Set Inverse" would fix it. Alright, this should do the job. This means that the bug has been solved and this topic is closed as solved :D

Demeter Dzadik commented

2019-07-26 15:55:48 +02:00

This means we found a workaround, and there might still be a bug here to fix ^^

A dev will hopefully come around eventually and decide.

This means we found a workaround, and there might still be a bug here to fix ^^ A dev will hopefully come around eventually and decide.

William Reynish commented

2019-07-26 16:18:58 +02:00

Changed status from 'Open' to: 'Archived'

William Reynish closed this issue

2019-07-26 16:18:58 +02:00

William Reynish self-assigned this 2019-07-26 16:18:58 +02:00

Demeter Dzadik commented

2019-07-26 16:56:45 +02:00

Not a bug then? :P

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Child of constraint target bug #67729