[IGSTK-Developers] Re: Tool orientation calibration

[Patrick Cheng]

Hi David, Julien and James,

I will try the PrincipalAxisCalibration.

I just tried to add an additional offset to the CalibrationTransform, 
'AFTER' I did the registration. Trying to shift the 
CylinderSpatialObject around, and it's actually working, one end of the 
CylinderObject is overlap with the tip of the pointer pretty well.

However the transform reported by the tracker is not the the tip of the 
pointer now.

Julien, if we don't want to change the coordinate system and move the 
origin of the CylinderSpatialObject, I think there is a way to solve 
that. But the solution you are working on is the most safe way, just 
more work for you. :)

Patrick




David Gobbi wrote:
> Hi James,
> 
> Right now Patrick is just making the versor rotation himself (see his
> last couple list emails), but he should try out the 
> PrincipalAxisCalibration
> to see how it works.  It should be more intuitive.
> 
> The ReferenceCalibration class isn't needed right now, but in the future I
> can see it being useful for calibrating customized or specialized tools.
> 
> - David
> 
> P.S. I'm going to miss the T-con this week, tomorrow I fly to Vancouver.
> 
> 
> Hui Zhang wrote:
> 
>> Hi, David,
>>
>> Thanks for your comment. That class can be firstly tested with 
>> FourViewTrackingWithCT example. With the modified tracker tool 
>> calibration calculation, we can see whether this class will give a 
>> correct rotation element to transform the default Y-axis aligned 
>> igstkCylinederObject to Z-axis aligned tracked tools. I have tested it 
>> with the general rotation, such as from Y-axis to Z-axis and it 
>> returned the correct quaternion, but it needs to be verified in the 
>> real application.
>>
>> About the "ReferenceCalibration" class I mentioned before, I dunno the 
>> group's opition whether we need this component in the IGSTK. If they 
>> think it is worth to add this class and can be practically used in the 
>> real application, I can try to add it. For Patick's case, he can input 
>> the tip's translation (x, y, z) and another 'end point' such as (x, y, 
>> z + needle's length) to get the full calibration matrix, which can be 
>> input to TrackerTool's SetCalibrationTransform method. And as you 
>> pointed before, the interface of this class will be a bit tricky for 
>> it should handle all 'points' from 3D to 6D, that is what I am 
>> thinking about.
>>
>> Regards,
>> James
>>
>> ----- Original Message ----- From: "David Gobbi" <dgobbi at atamai.com>
>> To: "Hui Zhang" <zhang at isis.imac.georgetown.edu>
>> Cc: "IGSTK-developers" <igstk-developers at public.kitware.com>
>> Sent: Tuesday, December 20, 2005 11:34 AM
>> Subject: Tool orientation calibration
>>
>>
>>> Hi James,
>>>
>>> I've taken a good look at igstkPrincipalAxisCalibration,
>>> and it is exactly what we need for tracked pointers.
>>>
>>> Defining both the "Initial" and "Desired" orientation is
>>> a very good idea.
>>>
>>> The class will have to be properly tested with an actual
>>> tracker to make sure it is giving the correct results.
>>>
>>> Are you still planning to add a "ReferenceCalibration" class,
>>> for doing precise orientation calibration procedures for
>>> tools like needles where the "point" isn't fixed?
>>>
>>> - David
>>>
>>>
>>>
>>>
>>
>>
>>
> 
> _______________________________________________
> IGSTK-Developers mailing list
> IGSTK-Developers at public.kitware.com
> http://public.kitware.com/cgi-bin/mailman/listinfo/igstk-developers
> 
>