Querying the Center of an Object

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Old 02 February 2009   #1
Question Querying the Center of an Object

Hi there im currently doing an assignment where i need to find out the center of an object , anybody know the mel command to do this ?
 
Old 02 February 2009   #2
.
Depends...
on the shape of the object.


The bounding box area of an object does not always produce a center.
( which I believe is how Maya xform -cp works )
The center of a pentagon fer instance will be wrong if you xform -q -ws -rp
Even after "centering pivot".

As far as I know there isnt a mel command that will "truley" get center for every case.





( for the pentagon tho.. I believe u can git radius from any two "base's mid points" connected to their opposite "corner points" the intersection of jes two such division's would be a true pentagon center )

like:


The Manipulators represent false bounding approximation.




if u continue around the shape till finished then delete the base mid points' connecting edges
leaving center to corner points' edges:



we can now clearly see by the equidistant tris, the error of the manipulator position
( making a cylinder with 5 sides will produce caps with the same result... truely centered intersection of tri tips )

Not sure if this is what yer assignment requires, but I would recommend custom logic for finding center in real world scenarios ( i.e., yer glorious maya coding future )

Last edited by claydough : 02 February 2009 at 05:16 AM.
 
Old 02 February 2009   #3
//select -r [yourmesh]
CenterPivot;
vector $obj_c = `getAttr .c`;
print $obj_c
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Old 02 February 2009   #4
Thanks for the Replies

Hey guys thanks for the replies =D it all helps hey im totally new to the whole MEL scene so gettin my head around it slowly ;P , busy writing a basic lighting script so reason for asking was to find out the center of an object so i can snap the say " Spotlights " center of interest to the exact center of an object so they would be aimed at whatever object upon creation

But yeah ill keep grinding it :P
 
Old 03 March 2009   #5
Talking

Originally Posted by Dontnoun:
//select -r [yourmesh]
CenterPivot;
vector $obj_c = `getAttr .c`;
print $obj_c


`getAttr .c` what's c is stand for? who can tell me?
 
Old 03 March 2009   #6
getAttr .c 是 getAttr .center的缩写
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-----------will be done
 
Old 03 March 2009   #7
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