Help! Question about child object rotation!

[kazeno]

I parent a box to another one and rotate the box,
the box scaled and stretched!!
I don't know how to deal with it even change rotate tools setting!

Help me please

[ragtag]

Ahhh....this is the idiotic, yet mathematically correct, effect in Maya you need every 10000th time you parent something to something else that AW decided to make the default. If you have a parent object that is not scaled equally in all axis (has scale values of say 1 2 1), it's children will be transformed in its local space and be stretched and skewed when rotated. The work around is to only have such parent scale an equal amount in all axis, or Freeze transformations otherwise (note that Freeze transformations will reset the rotation axis and pivot points....urrrr).

Ragnar

[kazeno]

Ragnar , thank for your help
I freeze the parent and everything is ok in Maya
but when I export it to shockwave 3D , there is an error :
------------------------------------------------------------>
Rotate is animated, but rotate pivot is nonzero. Macromedia Shockwave 3D does not support pivots. The animation may not look the same as in Maya. If you see a problem, either set the pivot to (0,0,0), or introduce another transform in place of the pivot.
---------------------------------------------->

I don't understand what it means, could you give me more suggestion?
Thank you

[ragtag]

I haven't worked with Shockwave. But if you open up the Channel editor....Window>General Editor>Channel Control. And under the keyable tab find attributes called RotatePivotX,Y and Z and RotatePivotTranslateX, Y and Z...and move them to left field. They should now be visible in the channel box. I'm guessing that this is what shockwave is compaining about, and that these need to be zero for the export to work correctly. If you set them to zero, it will change the point in space that the object rotates around, so to get around this you could parent this object to a group or locator positioned at the point you want it to rotate about...and rotate that instead.

Ragnar

p.s. The Pivots are also available in the AttributeEditor under pivots>LocalSpace and Pivots>WorldSpace....though these attributes are kind of weird as they are not real attributes (they only set the ones mentioned above to a value).

[gaviez]

or, if you don`t want to freeze transform on your parent object (for animation needs for example) , you can group the second object and then parent the group to the first object....

gaviez.