What to look out for when Characterising a 3ds max biped?

#1

Hey folks, this has probably been around before, but I just want to check something about characterising a biped rig. I’m really new to MB, essentially using if for now as a glorified file transfer for my MOCAP .trc files, to get them into max as .fbx data, as at my Uni we don’t have the necessary plug-in to just go from EvaRT to Max.

Basically, I’ve opened 3ds max’s Biped rig from a .fbx, it’s come up fine, and I’m wanting to characterise it, but I’m sure there’s something to do with the Bip_Pelvis, and a couple of other bones that you have to watch out for when alt-dragging to the ‘base’ bones.

I’m sure saw an article about things to watch out for with Biped to MB characterisation, but I can’t for the life of me remember, so if any of you more experienced folk know what I mean, could you let me know what bones from the biped skeleton can cause issues, when applied incorrectly to the ‘base’ characterisation slots.

Many thanks :bounce:

#2

Hello,

Well, recently we had a huge order with transferring mocap to biped max animations.
Uhh. I can tell that in general mocap does not deal with max bipeds quite nice, the reason is - spine Rotations are transferred only to the uppermost spine in the spine column (if I am wrong, please correct me), and animation seems to be a bit stiff afterwards. Second thing, biped’s leg thighs rotate only in a certain plane, i.e. the character cannot turn his knees inwards and that causes sometimes awkward positions. So, we strive to have characters on simple bones in max for mocap, if biped is not an urgent necessity…
But well, that was just off a bit :)…

As to characterisation - I believe, it is characterized in a general way. But later on you’ll need to export animation to bvh format and load to your biped in max, right? We use for that a special BVH character with a special bones names set, which is understood by both MB and MAX. Perhaps, there is an easier way.

#3

Thanks for the reply :slight_smile:

Unfortunately, I'm kind of stuck having to use a biped character that I have modified, if I had time, I would sort out my own rig, but I'm creating some technical video's, and the character is literally a modified skeleton, rather than skinned.


I had a go at using .bvh, but MB wouldn't let me even export in that format until I had taken care of all the spaces in the names of the bipeds bones. Max of course using spaces everywhere, and it's generally much better practice to use underscores.
So I went into the max file, and swapped all the spaces for underscores in the hierarchy. I exported that to an .fbx, and brought that in as a set of bones. I mapped my MOCAP data to an actor, and did my best to characterise the bones manually. 

I was able to export the sequence as a .bvh this stime, but when I tried to bring it into max again, it threw me a big error about not recognising names of bones, and then saying a load of bones with particular names were missing.

I exported an fbx instead, and just tried to bring that in, I did actually get my animated data appearing, but the hips (which I guessed might be a problem) were thrown way forward in the z-axis, so it looked like he was being pointed crotch first in a wind tunnel, with his arms and legs almost perpendicular to the ground out behind him, with the animations trying to play.

I've had a go at trying to get hold of extension 2, as that has a biped template included, but beyond being a member of Autodesk Platinum, I've had no luck getting it. I've been looking around my usual torrents and sharing (I know its bad, but Im a student, I just dont have the cash:shrug:  ) but most are extension 1 .rars saying htere extension 2.

I'm sure its a characterisation error, so if anyone knows where to get extension 2, either free or cheap that would be a massive help to me, as I'm running out of options due the timeframe this has to be done in.

EDIT: Either that or if anyone knows how to get raw .trc data straight onto a max biped without the need for rare hyper expensive plug-ins, I will be extremely grateful :thumbsup:

#4

Hello, Howi,
This is the pipeline how to bring mocap from MotionBuiler to Max/biped:

  1. You bring your biped character to MB,characterize it manually, since MB will not understand biped names. You can leave spaces in the names, I believe, since my Character has spaces in his bones names and still working… Then you transfer mocap data from your actor to the Character and animate it in a usual way.
  2. Here is the BVH adaptation character: www.puppetteers.com/demo/bvh_adapt.zip (81 KB). It is inderstood by both MB and MAX. Do not change any names - they are conventional. You merge it into the scene and make your biped Character its input. Then plot animation to BVH’s skeleton, select BVH’s hierarchy from its hips, not root! Export to BVH.
  3. Open your biped scene in MAX. Create a NEW biped in that scene, load in Motion pannel BVH data to the new biped (it will be transformed slightly in his limbs, no worry!). Then you save animation as .bip file. Then you load animation from the .bip file to your firstmost BIPED character! It must be working.

As to MB extention 2 - yes, it contains a biped template, but it is not working. I did not figure out yet, what it is intended for and how it works… Anyone knows, by the way?

regards

#5

Many Thanks :slight_smile:

After much digging, i came across a copy of MB extension 2. I have tried the Biped template, and it’s hit and miss.

I had one modified biped character, and using the template, marker sets, and .fbx format for everything it worked fine. My pipeline was as follows:

Create biped > Export as fbx > Open in MB 7.5 exp 2 > characterise with the template > import .trc, and set-up on an actor as normal; then have the biped skeleton follow the actor stance > plot to the biped > Select all the biped components only and export as a Kaydara file (.fbx, animation only) > import the kaydara fbx to the original biped in the file which I exported from.

Up until now this worked a treat, but I just had a go with a new character, who isn’t even a modified biped, followed exactly the same principle, and no animation is coming through the import to max at the end, it’s as if I had forgotten to plot to the skeleton, but I haven’t.
I’ll give this bvh a whirl as hopefully that will fix it, many thanks for linking it, my Final Year Project is kind of hanging in the balance.

The only thing that is different is the amount of frames in the file that wouldn’t import properly.
Over the slider in MB, it gives the message ‘Too many keys for edit’ when I have any part of the skeleton highlighted. This is the only thing I can assume is disrupting what was a fuctioning workflow.

Either way, hopefully I won’t struggle to much with this .bvh stuff now, much appreciate you taking the time to link that for me Annakey :thumbsup:

EDIT: to answer your question on what the biped template is for, so far as I can tell, it just allows for automatic characterising of a biped skeleton so that it works properly. It allows any of the structure options that biped in max gives you to work as well, and sticks them all in the right slots.
Kinda handy for folks in a similar situation to me, who are trying to get Mocap into max via biped with relatively little blood or sweat. I don’t know if it has any further options as I have only used MB for Mocap transfer, and not for proper hand animation yet.

#6

I re-did the scene following the workflow, but when I bring the bvh into max, it says:

“end site” appears at an inappropriate place in the file

I haven’t encountered this before, and I’m not sure what it means

#7

"I re-did the scene following the workflow, but when I bring the bvh into max, it says:

“end site” appears at an inappropriate place in the file"

How do you bring the BVH into max? You should create a fresh new biped skeleton and in Motion pannel/Motion Capture menu load motion capture file .bhv to it (a “camera” icon), which you exported form MB. Doesn’t it work? Itsn’t it loading to biped skeleton?

#8

This is the image from my max scene. the 2nd/NEW biped is the skeletal one, and I can’t get the bvh in. I’ll have to have another go in the MB scene, as I did every thing with the actor and biped character properly. The BVH character follows the biped character and i made sure i plotted to bvh and selected its hierarchy via the hips, but something must have gone wrong at that stage.

#9

Fixed it, as I suspected, it was something simple in the hierarchy selection.

Seems, that somehow when I grabbed the hierarchy via the hips, it was still grabbing the node/reference and therefore wouldn’t import properly.

All sorted now, and I have my first successful .BVH, and hopefully now a foolproof method for the rest of my sequences.
Many thansk for all your help and expertise :thumbsup:

#10

Glad, you got it fixed finally!

#11

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