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View Full Version : uber problems with local rotation axis... (maya)


anthonymcgrath
10-16-2002, 04:12 PM
reet, I'm cheesed off here. I've read numerous books and tuts on local rotation but I'm still having problems. I think I need someone to sit in front of me and say 'right, this is how it is!' but theres bugger all anyone around near me in newcastle who can explain this so I'm countin on someone on cgtalk to help me out here!!!

Theres a link here to a basic skeleton I've made. Can someone tell me if my local rotation axis are okay on this skeleton?

I could be wrong here, but I want to get all the local axis to point in the same direction so x points along the joint. but then where do the y and the z have to point?

I THINK (and believe me, I wont be surprised if I'm heinously wrong!!) this model so far is okay but if anyone wants to stick a pair of arms on the skeleton with correct lra's on the joints and let me download it from somewhere then that would be cool. hell if you've just got a jpg for me to check out then thats just as good!!

help me out here ppl, I'm so sick of trying to understand lra's. for cg animation, you can kinda forget about it to a degree as the end result is just wysiwyg but I need to suss this out for ingame characters.

thanx in advance
anth
newcastle
uk


lra query (http://www.anthonymcgrath.netfirms.com/localrotationquery.zip)

bentllama
10-16-2002, 06:40 PM
LRA's for ingame characters really depend on the game's engine you are creating the data for. I have created skeletons for different engines that required one to be X down the joint and others to not have to be x down the joint and hold any orientation you wanted.

All a skeleton is is a bunch of transforms in space with parent/child information. X down the joint is usally needed to denote "bone length" or the distance from one transform to another. Ask your engineers/code monkeys what the engine requires...

Oh...and it is a good idea to have an axis pointing forward as well [Y if you have X down the joint]...I have found that axis pointing forward beneficial.

hope this info helps...

dwalden74
10-21-2002, 01:08 PM
LRA´s look fine to me.

Bentllama, why is Y-axis pointing forward better???

:beer:
david

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