Mesh parent bug #46698

New Issue

Matthew Singer · 2015-11-05T04:30:27+01:00

Matthew Singer commented

2015-11-05 04:30:27 +01:00

System Information
Win 7
Amd fx 4100 4ghz
8 gb ram
R9 280 3gb

Blender Version
The bug is in blender 2.76
working version 2.75

Short description of error
Take a look at the video, https://www.youtube.com/watch?v=cxiKUfxkROo
As you can see the Weapon is parented to a empty, empty parented to handbone.
No slow parent, i have had many other people on blenderforums test this and it is a bug.

I downloaded a old blender, 2.75 and there is no problem.

Exact steps for others to reproduce the error
See video.

**System Information** Win 7 Amd fx 4100 4ghz 8 gb ram R9 280 3gb **Blender Version** The bug is in blender 2.76 working version 2.75 **Short description of error** Take a look at the video, https://www.youtube.com/watch?v=cxiKUfxkROo As you can see the Weapon is parented to a empty, empty parented to handbone. No slow parent, i have had many other people on blenderforums test this and it is a bug. I downloaded a old blender, 2.75 and there is no problem. **Exact steps for others to reproduce the error** See video.

Matthew Singer commented

2015-11-05 04:30:27 +01:00

Changed status to: 'Open'

Matthew Singer commented

2015-11-05 04:30:27 +01:00

Added subscriber: @ChaosE

Campbell Barton commented

2015-11-05 05:22:56 +01:00

Added subscriber: @ideasman42

Campbell Barton commented

2015-11-05 05:22:56 +01:00

Please always include a blend file, in this case it may need to be simplified for a developer to efficiently investigate.

Jorge Bernal commented

2015-11-05 06:50:44 +01:00

Added subscriber: @JorgeBernalMartinez

Jorge Bernal commented

2015-11-05 06:50:44 +01:00

Please, check with current blender 2.76b

Matthew Singer commented

2015-11-05 07:36:56 +01:00

Sorry about that, here you go https://drive.google.com/file/d/0B9QC7XrOZ_52VG9lX1B0WHVrWmM/view?usp=sharing

Monster commented

2015-11-07 10:23:38 +01:00

Added subscriber: @monster

Monster commented

2015-11-07 10:23:38 +01:00

I created a much simpler demo file Demofile.blend.

My analysis:

Bone parented objects receive the played pose with a delay.

This demo increases the effect by playing with 10fps.

Increasing the fps is no option. The delay will result in visible effects, when the meshes of the skin and the bone parented object do not touch or intersect each other (out of synch).

Tested with 2.76 -> delay
Tested with 2.73 -> delay
Tested with 2.69 -> delay
Tested with 2.68a -> no delay

I created a much simpler demo file [Demofile.blend](https://archive.blender.org/developer/F253624/Demofile.blend). My analysis: Bone parented objects receive the played pose with a delay. This demo increases the effect by playing with 10fps. Increasing the fps is no option. The delay will result in visible effects, when the meshes of the skin and the bone parented object do not touch or intersect each other (out of synch). Tested with 2.76 -> delay Tested with 2.73 -> delay Tested with 2.69 -> delay Tested with 2.68a -> no delay

Monster commented

2015-11-07 13:44:40 +01:00

Tested with 2.76b -> delay

Orlin commented

2015-11-07 17:34:52 +01:00

Added subscriber: @haidme

Orlin commented

2015-11-07 17:34:52 +01:00

I think, this bug has nothing to do with the object parenting, it's somehow connected to the IK solver or bone -> follow object IK controller. I've experienced this also in Blender 2.49b. The bug appears when you are trying to change the bone transformation with IK follow object set in it. You can see in the attached file, that not only the object(rifle) is fluctuating but also all bones that are children to the IK bone, that is transformed (look at the left hand).
Tested on 2.76.
Bug1.blend

I think, this bug has nothing to do with the object parenting, it's somehow connected to the IK solver or bone -> follow object IK controller. I've experienced this also in Blender 2.49b. The bug appears when you are trying to change the bone transformation with IK follow object set in it. You can see in the attached file, that not only the object(rifle) is fluctuating but also all bones that are children to the IK bone, that is transformed (look at the left hand). Tested on 2.76. [Bug1.blend](https://archive.blender.org/developer/F253655/Bug1.blend)

Monster commented

2015-11-10 11:22:16 +01:00

The demo does not contain any constraints.

Ulysse Martin commented

2015-11-11 02:20:22 +01:00

Added subscribers: @panzergame, @you.le

Ulysse Martin commented

2015-11-11 02:20:22 +01:00

So it seems that @panzergame patch: https:*developer.blender.org/D1600#inline-16417 solves the issue. I made a build to test Tristan patch on Windows: reuploading... https:*drive.google.com/file/d/0B3GouQIyoCmrdGxROEhsTUEzWU0/view?usp=sharing (blender 64bits)
@monster and @ChaosE: Could you test the build to confirm please? If you're running on another OS, I can make another build (windows 32, Linux 64, Linux 32). If it works for you, could you leave a comment https://developer.blender.org/D1600 ?
Thanks!

So it seems that @panzergame patch: https:*developer.blender.org/D1600#inline-16417 solves the issue. I made a build to test Tristan patch on Windows: reuploading... https:*drive.google.com/file/d/0B3GouQIyoCmrdGxROEhsTUEzWU0/view?usp=sharing (blender 64bits) @monster and @ChaosE: Could you test the build to confirm please? If you're running on another OS, I can make another build (windows 32, Linux 64, Linux 32). If it works for you, could you leave a comment https://developer.blender.org/D1600 ? Thanks!

Bastien Montagne commented

2015-11-20 12:31:15 +01:00

Added subscriber: @mont29