Custom rigs in 3ds max - Need help with arms.

t4paN

So, I'm working on this custom rig for a class (animation for games) and I'm creating my rig using bones as per the tutorial 3ds max has. My problem lies with the double rotation of the bones bellow the elbow that end at the wrist.

So that the wrist polygons don't twist, you are supposed to use 3 small bones that are snapped and linked to the main bone of that area, as in the pic bellow.

My problem is this: the max tutorials don't explain what you're supposed to do with these frigging little red bones and I'm not quite sure I can figure it out myself.





At a guess, I'd say that I apply 1 HI solver from the hand to the first bone, one from the 2nd to the bicep bone and one from the last red bone to the shoulderblade/clavicle. I'm pretty sure that's not the case though.

Any insight or better ways to do this would be appreciated. I saw one tutorial of some guy doing this with just three bones, one for the shoulder/elbow and two for the elbow/wrist area (one after the other, not overlapping). Is this a good option?

Thanks in advance

Mark Dygert

I haven't looked at the tutorial in a while but if they are "twist bones" or "helper bones" they come into play when you weight your character. Depending on how much wrist action your character has, you might be able to get away with none, or maybe one twist bone. Sometimes you might have to set up an expression or a state in reaction manager so you that the twist bone rotates a set amount when the hand rotates.

The idea is that each bone twists a little less as it gets back toward the elbow, when the hand bone rotates to help spread the rotation down the arm. It helps mimic the complicated two bones in the forearms that actually allow you to twist your hand.

Or if its just a helper bone it doesn't do anything other then hang out between two bones and act as a 3rd bone you can weight to. It helps keep the joint from collapsing.

I think if you follow the tutorial all the way to the end, it explains how to weight twist bones, and how to set up an expression so they rotate, but its been a while since I looked at it.

aesir

I havent created a rig in ages, but Im pretty sure you use orientation constraints on those three bones. You contrain them to both the forearm and to the hand. Then you adjust the percentage of each contraint so that the one closest to the hand has the most hand twist and the one closest to the elbow has the least hand twist.

That what you needed to hear?

Archanex

yeah basically there are a lot of different ways to set up this sort of a forarm twist if you get stuck doing it the way the max tutorial is telling you, here is one alternative.

http://www.jhaywood.com/croiProjectArm04.htm

monster

I use Rigging ArmyKnife (1.8) to rig just about everything.
http://www.wahooney.net/download.php?list.2

Here is a video tutorial to do what you want in less than 2 minutes.
http://www.wahooney.net/download.php?view.30

Max 9 sometimes has problems getting the quickwire feature to work.

t4paN

[ QUOTE ]
I havent created a rig in ages, but Im pretty sure you use orientation constraints on those three bones. You contrain them to both the forearm and to the hand. Then you adjust the percentage of each contraint so that the one closest to the hand has the most hand twist and the one closest to the elbow has the least hand twist.

That what you needed to hear?

[/ QUOTE ]

Man, that made it even more complicated, I don't even know what orientation constraints are :P


[ QUOTE ]
yeah basically there are a lot of different ways to set up this sort of a forarm twist if you get stuck doing it the way the max tutorial is telling you, here is one alternative.

http://www.jhaywood.com/croiProjectArm04.htm

[/ QUOTE ]

That'll probably help, by the looks of it it explains things a bit easier. Thanks a lot!

Thanks for the replies guys, I'm off to try that tutorial, I'll let you know if it works for me. Thanks again.

t4paN

Feel free to delete this and the post bellow -_-

t4paN

I wasn't trying to postwhore or anything but yeah, feel free to delete these last two posts.

MoP

You know, you could just edit your last post instead of replying to yourself 3 times

t4paN

[ QUOTE ]
yeah basically there are a lot of different ways to set up this sort of a forarm twist if you get stuck doing it the way the max tutorial is telling you, here is one alternative.

http://www.jhaywood.com/croiProjectArm04.htm

[/ QUOTE ]

If anyone has seen this tutorial and/or worked with the spline option for the twist bones I'd appreciate some info... For some reason, I can't use this technique on both hands; I've copied the bones with no IK from the start, and when I do the same thing on the second arm it folds the last twist bone. It's really strange

Mark Dygert

Currently I'm using biped for all our characters we have some really complex hand movements and gestures and using Bipeds twist bones is incredibly easy to set up and use. You really don't need a tutorial but I believe max has biped twist bones well documented in the biped reference/help.

Mirroring bones is tricky, mirroring bones with IK is a nightmare. I suggest you mirror the bones, reset xform, check your pivots and make sure they are aligned properly, then set up the IK for that limb from scratch. Flipping and rotating bones with IK attached also inverts a lot of the behinds the scenes math.

Neox

Holy cow, reset xform on Bones?! Then they will lose their local rotation, right? Why not use the Bone Mirror Tool?

t4paN

[ QUOTE ]
Currently I'm using biped for all our characters we have some really complex hand movements and gestures and using Bipeds twist bones is incredibly easy to set up and use. You really don't need a tutorial but I believe max has biped twist bones well documented in the biped reference/help.

Mirroring bones is tricky, mirroring bones with IK is a nightmare. I suggest you mirror the bones, reset xform, check your pivots and make sure they are aligned properly, then set up the IK for that limb from scratch. Flipping and rotating bones with IK attached also inverts a lot of the behinds the scenes math.

[/ QUOTE ]

We have to use bones for two classes instead of bipeds, so I had to learn how to do it. Like SekNeox said, Bone Mirror tool is the way to go.

/edit btw, I'm indeed mirroring just the bones and then setting the IK's from scratch, it's the "cleanest" way around it and I don't wanna get involved with more fancy IK mirroring stuff

[ QUOTE ]
Holy cow, reset xform on Bones?! Then they will lose their local rotation, right? Why not use the Bone Mirror Tool?

[/ QUOTE ]

Man, I saw the bone mirror tool so many times next to the refine button and it didn't even register. I'm just plain stupid, there's no way around it I went to class and asked my professor about it, and he was like "what you are you using, the mirror tool?" with a really weirded-out look on his face. Then he tells me about the bones mirror tool and I was like "shit, what a jackass".

Thanks for the help guys.