Max Biped tips / tricks?
polycounter lvl 9
Hi guys, I was wondering if I could get some general tips for working with 3dsMax Biped and just generally discuss / rant / ramble...
- Do you prefer Euler or Quaternion rotations? Why?
- getting looping and offset animations with TCB
- how do you get around unpredictable foot rotations when using different key types in one animation? (best way I've figured out so far us to use "control keys" before and after a slide / planted / free key to try to prevent overly sweeping function curves)
- for swords or other such props.. Animate the arm or the weapon? (I've recently switched to the arms, but still get occasional Gimble issues with certain wrist rotations like pronation)
I welcome any and all thoughts and discussion on these and anything else you guys can think of
- Do you prefer Euler or Quaternion rotations? Why?
- getting looping and offset animations with TCB
- how do you get around unpredictable foot rotations when using different key types in one animation? (best way I've figured out so far us to use "control keys" before and after a slide / planted / free key to try to prevent overly sweeping function curves)
- for swords or other such props.. Animate the arm or the weapon? (I've recently switched to the arms, but still get occasional Gimble issues with certain wrist rotations like pronation)
I welcome any and all thoughts and discussion on these and anything else you guys can think of
Replies
I always use Quaternion. I never even consider Euler. The times I've used Euler I end up with a jittery animation. It's just not a polished feature.
The easiest method (without Euler curves) is to use "Tripling". Where you duplicate the animation keys twice, and export the middle segment. For example, if your animation is 0 - 30 on the time line. Duplicate the keys to 30-60 and 60-90, and export 30-60. Sounds tedious, but it just takes a few seconds to do it. And I tend to only do it when I'm done iterating and not while I'm working.
I'm not experiencing any unpredictable rotations. I think maybe you aren't understanding the TCB controller fully. You can set the Continuity to 0 if you want to prevent overshoot. The little graph in the TCB window seems arbitrary but if you use a TCB position controller on a box, it makes more sense.
Another Example
I typically animate the arms. TCB (quaternions) shouldn't gimbal lock. I'd have to see an example of what you are describing.
I leave "separate tracks" at the default settings. With it off, that entire system "arm" or "leg" are treated as one key. If you want to move the forearm, it move the bicep also, unless you turn on separate keys. BUT I've run into issues when it's turned on. I go to copy or move a few keys and it copies or moves everything, not just the keys for the rest of the arm or hand but all of the keys in the animation for that system.
The main annoying bug that chaps my rear is the isolate curve doesn't work properly, specifically on the COM. It won't let you select keys on X if Y and Z are hidden, actually it selects Y but won't let you do anything with it unless you unhide it. So you have to have one other track shown in order to select the one you want, which is really crappy if they overlap.
Not being able to move X keys past Y or Z is annoying but I've learned to live with it and really, how often do you need to do that?
Switching from position to rotation tracks on the COM, in the standard curve editor can lock the curve editor on one or the other. You have to open the work bench and use the drop down menu to toggle it, but this doesn't free the buttons in the standard curve editor, they stay locked. Only restarting 3dsmax will fix it.
Despite it's warts, I love biped. It's fast, robust and production tested in MANY studios. It handles loading and mixing animations between rigs of different configurations extremely well. It also handles mixing different animations on separate body parts really well too. The rig itself is rock solid I've never had a biped go corrupt or fail to load animations. I know exactly what I can get out of it, which is a hell of a lot, in a short amount of time. That dependability and durability beats all but a few other rigs. It's been around forever but it does it's job really well. It might be a little annoying but it doesn't break on you and leave you high and dry.
Also, this script is pretty good for setting quaternion tangents to preset values, pretty quickly.
http://www.scriptspot.com/3ds-max/scripts/bipedkeyer-v1-4
Jim Jagger has a pretty good floating biped selector.
http://www.jimjagger.com/Pages/Tools/JJTools.htm
I keep it installed but I barely use it now because, one of the nicest things I've ever done to a biped, is toss an edit poly on top of the biped pieces and attach segmented copies of my characters mesh so the rig disappears. Selecting the joints becomes insanely intuitive.
You can hide the skinned mesh and get a huge preformace boost by viewing only the biped. Whatever you click on is going to select the part that you want. Want a bicep, click it! No more hunting around for a piece buried deep inside a mesh.
It can take a while to set it up, but I've scripted a lot of shortcuts and custom tools to automate the process. Still after using it on a few projects, it's hard to go back and I would set it up manually if I had to.
The official documentation for Biped Euler/Quaternion is pretty through but doesn't discuss the potential pit falls...
http://knowledge.autodesk.com/support/3ds-max/learn-explore/caas/CloudHelp/cloudhelp/2015/ENU/3DSMax/files/GUID-BD1BAA6F-57CE-4622-BE53-AA49EC37FCCF-htm.html
Monster, I'm on my phone atm, but I'll try to describe the gimbal lock situation. Say you want to animate a slashing combo on a right handed character. They would swing the sword down and to the left, then flip the wrist over to swing back up and to the right, but using the same edge of the blade, leading with the knuckles not the thumb.
I practice some sword work as a hobby, so I know what I want the rig to do, which would be to pivot the hand and wrist around the long axis of the sword, keeping the tip pointed at the same spot before the second swing. However, the rig will always rotate along the wrist axis, which brings the tip of the sword up and over in an arc. So I'm not sure if I'm rotating on the wrong axees, the wrong pivot points, etc.
Sorry if that's vague, I'll try to get a screen shot tomorrow.
The blue line is the path I intend to take with the tip of the weapon, but as you can see by the red trajectory, there is an abrupt bounce as the wrist rotation takes it up and over. Keying in the middle will smooth it out slightly, but there are still issues before and after. I'm guessing this is where you start to adjust the TCB's?
The weapon should have it's own controller. The best thing is to use a Biped Prop, then you can set those keys to world rotation. That'll keep the weapon from swaying when the hand twists.
just a quickie
previously when I wanted to animate character using bip I went around linking/parenting all of that characters joints to each bip part.
the character was already skinned and what not, so all I needed was the bip controller rig - but I understand that bip is also a skeleton in it self, which you bind to a mesh?
so my question is - assuming I went about it the wrong way, is there a way to just drive the joints on a previously skinned and boned character using bip? not having to go joint by joint and parenting it to each controller..
but rather assigning each joint to a control object?..
I don't want to say this but, sort of like you'd do in maya's human IK system or the motion builder rig/character..
thanks, sorry I stole the thread there
Keeep the knowledge flowing!
Not that I've ever heard of. I know you can transfer animations between bipeds, but I've never seen a way to put a skeleton to biped. I've learned a few things in my time, and one of them is that sometimes its faster and easier to do something over than to try to fix or work around it. In this case, I'd just re-skin the mesh to a biped.
damn son.. thanks
I'll parent the already skinned joints under the bip controllers then, like I have been doing..
it's all for practice, not going into an engine or anything so the hiarchy can be messy as long as the character animates ;D ..once I get around to using bip, it's gonna be setup the way they want it and I just have to animate
but thanks, now I know
I did find some autodesk character creator thing, which had a max script which transfers bones to bip, but it's all very strict name conventions hard coded in the script so... lazy autodesk mongs
OR just reskin it, that might be faster depending on the model.
Each biped piece is it's own controller so you don't need extra shapes or geometry to control it.