Re: [ggt-devel] Question about EulerAngleZXY, XYZ, ZYX

[Doug M. <mc...@ia...>]

Allen Bierbaum wrote:
> Doug McCorkle wrote:
> 
>> Allen Bierbaum wrote:
>>
>>> Allen Bierbaum wrote:
>>>
>>>> Unfortunately, it looks like there are some bugs in the conversion 
>>>> somewhere.  My guess is that there are some border cases in the 
>>>> extraction of the euler angles from the Matrix.
>>>>
>>>> I have added a new test case that exhaustively tests all Euler 
>>>> getting and setting to find these issues. The test can be found in 
>>>> the MatrixGenTest test case.  If anyone has some time to look into 
>>>> this, you can use this test case to reproduce the problem.
>>>
>>>
>>>
>>>
>>> I just commited some changes that should fix the errors. (at least it 
>>> fixes the ones the test case found :)
>>>
>>> Give it a spin and let me know.
>>>
>> Just do a cvs checkout I assume?
>>
> Yep.
> 
>> Thanks for the prompt response. This was going to be my evening 
>> project but I guess I can do some testing instead. I appreciate the help.
> 
> 
> I wasn't planning on working on it, but I had some down time waiting for 
> some builds and I found a good solid algorithm in a reference so I just 
> gave it a try.
> 
Ok. It appears that things are better but not quite right. If rotations 
are purely about an individual axis X,Y,Z everything works fine. If 
rotations become compounded things begin to act odd. This affect may be 
due to us not understanding how rotations are applied in OSG though so 
I would like to do more testing. Some things do appear to working better 
but one odd thing did occur. With EulerXYZ under the old version of gmtl 
  the compound rotations appeared to work correctly no mater what had 
been done. This does not appear to be working now. I will continue to 
test and try to provide better feedback.

> -A
> 
>>
>>> -A
>>>
>>>>
>>>> -Allen
>>>>
>>>> Doug McCorkle wrote:
>>>>
>>>>>  Hello,
>>>>>      When using gtml I noticed that when I pass an identity 
>>>>> Matrix44f into
>>>>>  make< gmtl::EulerAngleZXY >( identity ) that I get back 90,0,90. If I
>>>>>  ask for an EulerAngleXYZ I get back 0,0,0 and ZYX return 0, nan, 
>>>>> 0. Is
>>>>>  this the correct behavior of EulerAngle? I thought that no matter 
>>>>> what
>>>>>  Euler combination that I ask for should return 0,0,0 for an identity
>>>>>  matrix. Thanks for the help in understanding this better. I am using
>>>>>  gmtl 0.4.5.
>>>>>
>>>>>
>>>>>  Doug
>>>>>