View Full Version : Anchoring Nulls

09-04-2011, 01:10 PM
I've been using Lightwave since the early 90s. For a dozen years or more I've been waiting for them to fix an obvious issue but it never gets fixed. It's the same way in Lightwave 10 so either there's a workaround or I have to abandon hope. The issue is with anchoring nulls. In Messiah, Maya, XSI basically all the other packages when you move a foot null the other foot or feet stay planted. Also if you move a body bone they will also shift position. It's meant endless tweaking to get the nulls back to when they are supposed to be and they are never a 100% lock on the surface. It's one of several reasons I'm finally ready to switch to Maya but I thought I'd see if some one knew a workaround?

There's another related problem. In Maya, or as I have said even Messiah, when I move a foot null the whole body shifts, leaving the other foot/feet of coarse planted. It's a wonderful feature that makes it more like grabbing a physical puppet and makes the animation more organic. With Lightwave the influence stops at the top of the chain so all you move is the leg or arm and nothing else. It may make sense to a programmer but to an animator it's like having your hands tied. The question is there some way to make the influence go up the chain to influence the entire bone structure? I thought for sure when Messiah came out 12 years ago they would have seen the light and fixed the bones. I was so sure they would have in Lightwave 10 I just assumed the change would be there but it's not.

These two issues are 2/3s of why I've all but given up on Lightwave. I'm hoping some one knows of a workaround for both since the software doesn't do it passively like all the rest.


stiff paper
09-04-2011, 03:47 PM
RebelHill on YouTube:-

Those two links contain many videos that will probably be of interest. If I remember rightly, at least one of them features an "auto-walking" rig.

RH also has a home page where he sells his rigging training and his automatic rigging solution, "RHiggit!"
There are free downloads of rigs and also the first... umm... I think 3 hours of his rigging training, so you can try before you buy.

In truth, I expect he might be along any moment now... he's the go-to guy for rigging in LW.

09-04-2011, 09:46 PM
I bought something similar for Maya that never worked. I couldn't even get a straight forward tube to work with it and I could swear it was the same name.

I know how to rig and weight characters it's the fact the nulls influence each other that drives me nuts. Moving the front legs on a four legged character shouldn't cause the back leg nulls to move. Everything is parented properly and I use both Positioning and Main nulls for control it's the fact that they can cause them to move when you don't want them to move. There's also the issue of skating caused by the nasty loops the IK causes in the splines but I know how to get rig of that.

Guess the real solution is Maya. It just seems there should be a way in Lightwave. Lightwave is fast to work but it's a real headache for character animation.

09-05-2011, 04:35 AM
I dont have any real idea what this problem you're having is... it certainly shouldnt be happening.

Open an empty scene... create 2 nulls, not parented to one another, and move one... does the other move? No, ofc it doesnt... So there IS NO influence between one null and the other at all...

Now, obv you're talking about character rigs, so if you're seeing something like this, then three's pretty much no other answer than you've got a badly made rig.

SO, some possibilities...

First, when you move the null controlling one limb, does the null of another actually move, or does the IK bones in other limbs just shift about... or both?

I cant imagine what would cause the other null to jsut move around on its own, unless for some reason its been constrinaed in some way to the one being moves.

If the IK bones of other limbs are moving, then most likely its because your IK chains arent setup correctly... they need to be terminated at the top of each chain, else the IK claculation will run up through the whole character, and making a change to one IK chain will cause effects in the others.

Now if the nulls at the ends of those IK chains are also set to "keep goals in reach"... then they'll be getting dragged along for the ride too. Those are your most likely causes.

So... in short, nulls WONT influence each other, unless there's something kooky in the rig that MAKES them do so.

As for the autowalk/auto hip thing... that's not something thats just "built in" to a given package... its part of a rig... If a rigger doesnt set it up, then you wont get that behavior in LW, maya, or anywhere else.. however if it is built and setup, you can have it, or something like it, in any package, including LW. Do note, that while such a feature seems like a nice intuitive control for an animator, a LOT of animators dont like such things, they prefer to have control of exactly where thigns move, and dislike automation much of the time.

Anyhow... download some of the character rigs from the shares section on my site... I doubt you'll find any such problems with them, cos there's nothing really wrong or broken about how LW does (or at least can do) character rigging.

09-05-2011, 12:59 PM
What RH said: there's no way non-parented nulls should affect each other.

Upload an example of what you're seeing and we'll diagnose it for you. It could save you a lot of money.

09-07-2011, 12:25 PM
Let me dig out a better model and rig. All of them are doing the same thing. I just set up a new machine and I still don't have most of the content transferred.

FYI. It's not just two nulls they need to be part of a rig. Let's say I set up a standard rig with the foot nulls parented to a positioning null when I move one foot null it causes the other foot to move slightly making it skate or move below a surface. On a more extreme move they can move quite a lot.

Thanks everyone.

09-07-2011, 12:46 PM
Almost certainly your IK isnt terminated. Possibly you may have insufficient pre-bend in your chains causing additonal problems. By all means post a scene.

09-07-2011, 12:51 PM
Don't foot nulls always have to be positioned to correspond to the motion of the Mover null? I mean, it'd be slick, but automatically I wouldn't expect anything better than a video game.