View Full Version : "same as item" constraint usage

08-26-2011, 05:46 AM
ok i feel like a total idiot now. i cant for the life of me work out how this works or find any info on it.

here's what i'm trying.

i want to set up a mocapd animation with some extra control bones to animate over the top of the captured data.

essentially i want a bone to follow the others rotation. you think it'd be simple. probably is although i am a bit brain dead today.

any pointers?



08-26-2011, 06:57 AM
Ull find it covered in the RHR 3hr sample set.

Though ull probably run into problems... especially if you're trying to build a rig with a "second" hierarchy that SAIs to the first (blendable).

The problem will come when you try to "load motion envelopes" onto the base, FK only bones, as all the realtions to those for the SAI controlled bones will break, and need to be setup again.

08-26-2011, 07:04 AM
hey craig,

could have layed money on you replying.

thanks, i've actually got your full training here at work. any pointers to which sections i should be looking at.

ta very muchly


08-26-2011, 07:20 AM
Its in the earlier vids, controls, constraints, expressions.

Maybe best just to pick through that whole section of details... as you may get ideas for using other tools than SAI to achieve the same, or similar control.

Btw... here's the bug that'll stop you dead in your tracks... www.rebelhill.net/LWbugs/RH_LFS-MME.mov In the example you see it breaks the SAI blending on an IK/FK control systems, but the same would be true if the constraint were blending between FBX/FK chains.

You can get around it by using multiMotionGN to load your motion envelopes instead of the LW native loader... so its not a total loss. You will however find that this wont load any of the SAI blend channels ([RotationItem.Blending])... nor of course masterchannels that have been keyed (used as control channels for the SAI blend)... to get those to transfer, you'll have to do a second import motion pass using the load from scene method, but loading/mergin only those channels, deselecting all regular controllers.

08-26-2011, 07:46 AM
Craig, I love your candidness. I laugh every time I go through your training. :)