blender crashes when add a inverse kineatics constraint to bone #49899

New Issue

Jean Da Costa · 2016-11-01T01:28:12+01:00

Jean Da Costa commented

2016-11-01 01:28:12 +01:00

when added a inverse kinematics to a bone it causes a crash.

my OS:
windows 7 ultimate x86
processor: amd phenon 9500 quadcore 2.21GH
nvidia geforce 6050SE nforce 430

blender version:
blender 2.78a hash e8299c8

the bug not is happening in previous versions.

steps
open blender, delete defaut cube and add a single bone, go to edit mode, extrude the bone tree times and duplicate the last bone, unparent it, go to pose mode and add a inferse kinematic constraint setup, uncheck use tail opition, and it will crash blender.

or simply enable auto IK and try editing the pose.

this file crashed blender all times:

console screenshot on exact moment of crash:

crash.blend
https://www.youtube.com/watch?v=yce51lIKgvU&feature=youtu.be

sory my bad english.

when added a inverse kinematics to a bone it causes a crash. my OS: windows 7 ultimate x86 processor: amd phenon 9500 quadcore 2.21GH nvidia geforce 6050SE nforce 430 blender version: blender 2.78a hash e8299c8 the bug not is happening in previous versions. steps open blender, delete defaut cube and add a single bone, go to edit mode, extrude the bone tree times and duplicate the last bone, unparent it, go to pose mode and add a inferse kinematic constraint setup, uncheck use tail opition, and it will crash blender. or simply enable auto IK and try editing the pose. this file crashed blender all times: console screenshot on exact moment of crash: ![vlcsnap-2016-11-02-17h19m47s941.png](https://archive.blender.org/developer/F390961/vlcsnap-2016-11-02-17h19m47s941.png) [crash.blend](https://archive.blender.org/developer/F389914/crash.blend) https://www.youtube.com/watch?v=yce51lIKgvU&feature=youtu.be sory my bad english.

Jean Da Costa commented

2016-11-01 01:28:12 +01:00

Changed status to: 'Open'

Jean Da Costa commented

2016-11-01 01:28:12 +01:00

Added subscriber: @jeacom

blender-admin commented

2016-11-01 01:28:12 +01:00

#50033 was marked as duplicate of this issue

Jean Da Costa changed title from ~~blender crashes when add a inverse kineatics constraint is added to bone~~ to blender crashes when add a inverse kineatics constraint to bone

2016-11-02 15:05:15 +01:00

Aaron Carlisle commented

2016-11-03 19:07:55 +01:00

Added subscriber: @Blendify

Aaron Carlisle commented

2016-11-03 19:07:55 +01:00

I could not reproduce maybe an 32-bit thing?

Ray molenkamp commented

2016-11-03 20:06:11 +01:00

Added subscribers: @Sergey, @LazyDodo

Ray molenkamp commented

2016-11-03 20:06:11 +01:00

It's a mem alignment issue in bf_intern_iksolver, none of the classes care about their alignment, yet they use eigen which really wants them to be aligned at 16 byte boundaries (for vectorization reasons) , this can be fixed by overriding the class new and delete operators like this

	void* operator new(size_t i)
	{
		return _mm_malloc(i, 16);
	}

	void operator delete(void* p)
	{
		_mm_free(p);
	}

But it feels a little dirty to cut / paste that all over the place? Given this is not the only place in blender plagued by this (ge_phys_bullet ge_converter and bf_intern_libmv emit similar warnings, for at total of 20+ classes in blender that have this issue ), Bullet is by far the worst offender, and in never versions they solved it with a macro like this

http://www.letworyinteractive.com/blendercode/d0/d6b/btScalar_8h.html#a0bd5b84db13a000ac43fffe2bfc32187

Sergey, what's the preferred way of addressing this in blender?

It's a mem alignment issue in bf_intern_iksolver, none of the classes care about their alignment, yet they use eigen which really wants them to be aligned at 16 byte boundaries (for vectorization reasons) , this can be fixed by overriding the class new and delete operators like this ``` void* operator new(size_t i) { return _mm_malloc(i, 16); } void operator delete(void* p) { _mm_free(p); } ``` But it feels a little dirty to cut / paste that all over the place? Given this is not the only place in blender plagued by this (ge_phys_bullet ge_converter and bf_intern_libmv emit similar warnings, for at total of 20+ classes in blender that have this issue ), Bullet is by far the worst offender, and in never versions they solved it with a macro like this http://www.letworyinteractive.com/blendercode/d0/d6b/btScalar_8h.html#a0bd5b84db13a000ac43fffe2bfc32187 Sergey, what's the preferred way of addressing this in blender?

Sergey Sharybin commented

2016-11-03 21:49:43 +01:00

We can have something similar, yes.

Did you check if using aligned attribute on class and/or property helps?

We can have something similar, yes. Did you check if using aligned attribute on class and/or property helps?

Ray molenkamp commented

2016-11-03 22:23:27 +01:00

It doesn't, it only really helps for things that are allocated at compile time the docs ( https://msdn.microsoft.com/en-us/library/83ythb65.aspx ) mention

Note that ordinary allocators—for example, malloc, C++ operator new, and the Win32 allocators—
return memory that is usually not sufficiently aligned for __declspec(align(#)) structures or arrays of structures. 
To guarantee that the destination of a copy or data transformation operation is correctly aligned, use _aligned_malloc, or write your own allocator.

It doesn't, it only really helps for things that are allocated at compile time the docs ( https://msdn.microsoft.com/en-us/library/83ythb65.aspx ) mention ``` Note that ordinary allocators—for example, malloc, C++ operator new, and the Win32 allocators— return memory that is usually not sufficiently aligned for __declspec(align(#)) structures or arrays of structures. To guarantee that the destination of a copy or data transformation operation is correctly aligned, use _aligned_malloc, or write your own allocator. ```

Sergey Sharybin commented

2016-11-03 22:28:03 +01:00

Hrm, so we'll need to do aligned-alloc for those classes. For that doing something what you showed should work (we should be able to use EIGEN_MAKE_ALIGNED_OPERATOR_NEW).

However, not sure that will be enough. Thing is, even object itself is aligned it doesn't mean its properties are aligned, so guess alignment attribute is still needed?

Hrm, so we'll need to do aligned-alloc for those classes. For that doing something what you showed should work (we should be able to use `EIGEN_MAKE_ALIGNED_OPERATOR_NEW`). However, not sure that will be enough. Thing is, even object itself is aligned it doesn't mean its properties are aligned, so guess alignment attribute is still needed?

Ray molenkamp commented

2016-11-04 00:30:36 +01:00

Judging from https://eigen.tuxfamily.org/dox-devel/group__TopicStructHavingEigenMembers.html the eigen classes have aligned attributes on them, so the structure layout will be aligned at compile time. EIGEN_MAKE_ALIGNED_OPERATOR_NEW makes sure that whenever you new up a class it'll be aligned as well.

Ray molenkamp was assigned by Bastien Montagne

2016-11-04 10:09:53 +01:00

Alexandre LAB commented

2016-11-05 12:03:07 +01:00

Added subscriber: @Almisuifre