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View Full Version : xyz OR xzy joint rotations_ i've heard both answers now..

c000be
02-21-2009, 09:49 AM
and i would like some clarification.

one guy uses xzy joint rotations on a biped, and another xyz joint rotations on a quadriped on the training demos.

my baboon character will be both [as they sometimes do in real life, in fact]. as long as i've put my initial x axis going down the joint, the z axis going forward and the y axis up initially, the mirror i then used is a YZ function, and as long as i don't go in and redo any of the local rotation axis, i get the mirror behavior function working as expected for both xyz and xzy rotation orders.

is the fact that i used YZ for the mirror function a factor, and any other info would be greatly appreciated. sorry i can't ask a better question if anyone has a better answer to what i'm trying to figure out here. thanks
Buexe
02-21-2009, 10:03 AM
There is now simple answer to this. Basically it is necessary for each individual joint to determine the best rotation order, depending on what kind of motion you expect it to perform. The one with the most significant motion should be last. Turn on gimbal rotation mode if your package supports it and check what rotation order produces what kind of effect to your rotation axis`.
c000be
02-22-2009, 05:48 PM
a little more clarification in my question, since the model seems to move well with either xyz or xzy joint orientations. this character has to move well in every direction except for flying, basically.

does the axis going down, say the x following the child, the y pointing up and the z to the side have to do with the joint rotation order than i'm figuring out at this point. [and again, i mirrored the behavior across the YZ axis if that matters]
and in the meantime, i am looking at other peoples rigs that i downloaded from highend3d that got good ratings, to help myself figure this out.

thanks.
stewartjones
02-22-2009, 09:39 PM
Change your rotate mode to 'Gimbal' and have a look at what's really going on. From there you should be able to sort out which rotation order will be best for you in this situation.
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