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geothefaust
04-16-2009, 05:29 PM
Hey all,


I'm looking for a good way to offset a null that is being used to control an IK chain for an arm.


Basically, when the arm is in a certain position, gimbal lock occurs. To fix this issue, in my current setup I have:

Null offset> Controller> IK goal

Offsetting null


What I do is when I need to fix the gimbal lock issue, I have a slider to control the Same as Item for the Null offset to the rotations of the Offsetting null. This of course, does solve the gimbal lock issue. However, being that the controller null is away from the it's parent, it then rotates accordingly. I'm trying to come up with a solution, alas, I'm a little tired and a bit frustrated at the moment, so I thought I would instead solicit ideas before moving on.


Suggestions are most welcome. Thanks!

RebelHill
04-16-2009, 07:16 PM
nope...

IKgoal(main)>Offset

The chain goes to the offset itself

Ill be posting an advanced rig in tomoz or sat... all ur questions will be answered therein.

RebelHill
04-16-2009, 07:20 PM
heres a preview... almost finished.

geothefaust
04-16-2009, 08:15 PM
Cool man. I'm eager to see what you're up to there.. Thanks for the possible future solution. :)

geothefaust
04-16-2009, 08:56 PM
One of the things I'm having happen, is that using same as item in this particular scene/rig for offsetting, it's not offsetting fully.

I set all of the rotations of one item, to same as item for my offsetting null... And the result is halved. For instance 90 degrees on my offsetting null, will result in only 45 degrees on the affected null.

What on Earth would cause this? It doesn't do that to me in any other scene. It also recently showed up and I can't narrow down the problem. I've cleared my configs, I've tried changing all sorts of stuff, but it never works. But when I create a new scene file, or open different one, same as item works normally.

Silkrooster
04-16-2009, 09:27 PM
heres a preview... almost finished.

Looks quite complex.

RebelHill
04-17-2009, 03:52 AM
I set all of the rotations of one item, to same as item for my offsetting null... And the result is halved. For instance 90 degrees on my offsetting null, will result in only 45 degrees on the affected null.

Its the fact that same as item seems to be evaluated before IK... the function is pretty weak imo, its basically EXACTLY the same as follwer, which we've had for years, but u cant after ik the thing, and u cant channel swap... Follower is much more versatile as a "lookup" operator, but doesnt have the blend option...

Its six of one, half a dozen of the other, typical LW, lol.

geothefaust
04-17-2009, 12:34 PM
Its the fact that same as item seems to be evaluated before IK... the function is pretty weak imo, its basically EXACTLY the same as follwer, which we've had for years, but u cant after ik the thing, and u cant channel swap... Follower is much more versatile as a "lookup" operator, but doesnt have the blend option...

Its six of one, half a dozen of the other, typical LW, lol.

Haha. No kidding!! Man I was all excited over it, and yeah it's great for certain circumstances, no doubt about that.

With the help of Castius last night, it looks like I may have reached a limitation with the Same as Item feature. I'm considering reporting it as a bug.

I would use follower, but unfortunately it cannot be enveloped. I guess that's what SimpleOrientConstraints, is for...

I'm also looking at dpkit right now for a nodal solution. Thankfully everything in there can be enveloped, and you can have all sorts of wicked setups.

RebelHill
04-17-2009, 01:35 PM
Well... U can sort of envelope follower, by putting follwer on an auxiliary item, and then using either orient constraint, or maprange expression to cross blend between the keyd value and the aux items value... but its another layer to have to build in, etc...

Ive yet to try doing some of these funky things with nodal... though I must try at some point... for the mo I can achieve pretty much everything in other ways... as u'll see, a lil later this evening.

geothefaust
04-17-2009, 03:31 PM
Cool man. Looking forward to seeing your smoking gun.