Blender Foundation: Blender 2.x BF release: Detail: 32286 Bone "Child of" constraint in Object- and Pose Mode

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[#32286] Bone "Child of" constraint in Object- and Pose Mode

Date:
2012-08-08 15:12 Priority:
3

State:
Closed

Submitted by:
George Miller (dr_brown) Assigned to:
Nobody (None)

Category:
Animation system Status:
Closed

Relates to: Duplicates:

Patches:

Summary:
Bone "Child of" constraint in Object- and Pose Mode

Detailed description

Hello,

I build an armature with on "root" bone and two "child" bones which are parented
to the root. One of the child bones copies the rotation of the other via an "Child of"
constraint. If I move all bone through the translation of the root (Pose Mode) bone,
all works properly but if I move the armature (in Object Mode), the bone with the
"Child of" constraint stand still. If I deactivate the constraint also the translation in
Object Mode works properly.
If I build the same armature again the problem don't occurs again, so please look
to the attached .blend file (first layer) to understand the problem. The second layer
contains the same armature without the problem.

Best regards

Tested with Blender (official release):
=============================================
= Blender 2.63 (sub 14) System Information =
=============================================

version 2.63 (sub 14), revision b'49072'. b'Release'
build date: b'2012-07-20', b'06:28:24'
platform: b'Windows:32bit'
build cflags: b'/nologo /Ob1 /J /W1 /Gd /we4013 /wd4018 /wd4244 /wd4305 /wd4800 /wd4065 /wd4267 /openmp -O2 -DNDEBUG -DWIN32 -D_CONSOLE -D_LIB -D_CRT_SECURE_NO_DEPRECATE -DOPJ_STATIC -DWIN64 -DWITH_MOD_FLUID -DWITH_MOD_OCEANSIM -D__LITTLE_ENDIAN__ -DWITH_AUDASPACE'
build cxxflags: b'/nologo /Ob1 /J /W1 /Gd /we4013 /wd4018 /wd4244 /wd4305 /wd4800 /wd4065 /wd4267 /openmp /EHsc -O2 -DNDEBUG -DWIN32 -D_CONSOLE -D_LIB -D_CRT_SECURE_NO_DEPRECATE -DOPJ_STATIC -DWIN64 -DWITH_MOD_FLUID -DWITH_MOD_OCEANSIM -D__LITTLE_ENDIAN__ -DWITH_AUDASPACE'
build linkflags: b'/SUBSYSTEM:CONSOLE /MACHINE:X64 /STACK:2097152 /OPT:NOREF /INCREMENTAL:NO /NODEFAULTLIB:msvcrt.lib /NODEFAULTLIB:msvcmrt.lib /NODEFAULTLIB:msvcurt.lib /NODEFAULTLIB:msvcrtd.lib'
build system: b'SCons'

System:
=============================================
Windows 7 Professional 64Bit
SP 1
Intel Core2 Quad Q9300 @ 2.50GHz

Python:
=============================================
version: 3.2 (r32:88445, Mar 2 2011, 16:59:21) [MSC v.1500 64 bit (AMD64)]

OpenGL
=============================================
renderer: 'ATI Radeon HD 3800 Series '
vendor: 'ATI Technologies Inc.'
version: '3.3.10750 Compatibility Profile Context'

Also tested on Vista 64Bit and with a (own) MinGW build of the same Blender
version and with Blender 2.52 with the same result.

Followup

Message

Date: 2012-10-19 18:17
Sender: Ton Roosendaal
A child-of constraint is similar to parenting a bone to another one, but with properties you can control. This is useful for cases like when you want something to be picked up during an animation.

Having such a bone already parented then gives strange situations, which cannot be solved. What you see outside of pose mode is actually correct here.
The child-of constraint is also a bit weak, it isn't fool proof and will only work in controlled and well setup sitations.

To copy rotations from to another bone you better use the "Copy rotation" constraint.

Attached Files:

Name	Date	Download

BugReport_ChildOf.blend	2012-08-08 15:12	Download

Changes:

Field	Old Value	Date	By

status_id	Open	2012-10-19 18:17	ton
close_date	None	2012-10-19 18:17	ton
Status	New	2012-10-19 18:17	ton
File Added	21688: BugReport_ChildOf.blend	2012-08-08 15:12	dr_brown