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Richard Hebert
09-10-2011, 05:35 PM
Hi Everyone,

I know this has been talked to death but I'm needing a little technical insight into motion files, Biovision in particular. I've used Poser in the past and imported just about any and every kind of .bvh file and it seems to get applied correctly regardless of the Poser mesh. How is this accomplished without the endless tweaking that is so prominent in LightWave? Sorry about beating a dead horse but I think I saw it move a little.

Richard

OnlineRender
09-10-2011, 05:48 PM
bvh is ok into lw , there is tweaking involved , mainly bone resting ...
truebones is the one to ask he will guide you .

any specific questions / problems ?

Richard Hebert
09-10-2011, 05:55 PM
Who is that???!!

cresshead
09-10-2011, 05:58 PM
http://truebones.com/

Richard Hebert
09-10-2011, 06:01 PM
I'm importing bvh files into LightWave and using IK booster to transfer data to a rig. The bones accept the data but often times in an erratic manner. I'm not a rigger and I cannot tell if the bones that I've created are oriented properly from the start. Could this be a culprit and if so how does one go about correcting the problem? Thanks for the speedo response btw.

Richard

OnlineRender
09-10-2011, 06:06 PM
chances are the bones are not rested/oriented hit " R " in bone mode " LAYOUT " ... or modeler ,sorry last time I tried it larry walked me threw me .... bvh throws some wobbler's excuse the pun ...........NT need a decent workflow rather than hacking it ....could be Wight maps , there is wads of reasons ..........sorry for vague answers

Richard Hebert
09-10-2011, 06:15 PM
That's quite alright. The bones are rested, does this eliminate any orientation issues? Still learning all this stuff.

Richard

OnlineRender
09-10-2011, 06:28 PM
depends what viewport the bones where created , I know there is an issue if you build the bones in the wrong viewport they will aligned to the given axis , so in-turn it could be WHATEVER app the bones dont sit right ....honestly I'm not the best person to ask , hopefuly truebones will reply if not I will ping him for you

Richard Hebert
09-10-2011, 06:34 PM
Thanks for the thoughts. It all helps. I'll be going to their site in a little while. There's something that I thought of and would like to try before asking their forum. I'll post how it turns out for future reference.

Richard

OnlineRender
09-10-2011, 06:39 PM
silly question , it evident you know LW , but is deform "ON" ?

Richard Hebert
09-10-2011, 06:49 PM
Everything deforms OK, getting rig data from the .bvh file is troublesome due to the 'gimbal bones' that come as part of the BVH rig. My bone setup doesn't have these
'gimbal bones' so the data doesn't get applied properly I'm guessing. Also, I'm noticing that my bones have some rotation in the rotate channel. I'm removing the rotate data and resting the bones again and it appears to bring the bone back to a 0,0,0 initial state just like a similar bone in the BVH rig. I'm thinking that this might help to correct the rotation problems. I'm still going to have to create those darn gimbal bones in my rig if I want to copy all the rotation at one time instead of bone by bone. Apparently, my rig has to have the same identical setup as the bvh rig even if the bones have no rotation data in them.

Richard

OnlineRender
09-10-2011, 06:54 PM
ahh sorry mate , Im gimped ,Craig aka RH maybe able to help or truebones , kurt aka the scientist will have more knowledge than me .........edit most people have more knowledge than me

here a YT video for your troubles ;) http://www.youtube.com/watch?v=np0solnL1XY&feature=player_embedded#! enjoy

Richard Hebert
09-10-2011, 07:01 PM
If that's Rebel Hill, you're talking about the Jedi Master now! If he doesn't know it, then it can't be known! Thanks for the tip! Free Bird... That was pretty cool!

Richard

RebelHill
09-11-2011, 06:45 AM
BVH is a pretty open standard, and skeletons come in many different layouts and designs... but still there is something approaching commonality in all the different skeletons you'll find. THe reason they all (or most) work so well with poser is the fact that all the poser rigs are basically the same too, the skeletons are a rough bvh "standard" biped, and so everything goes across no problem most of the time.

But in the traditonal "production" 3D softs a lot of this has been missing, as for years mocap has been a very cistom gig, with most productions handling their own, in different and varied ways, meaning that these softs have never developed the translators to ehlp bring in this widely available bvh data onto any kind of "standard" rig... cos it would get so little use in favour of specialisation and customisation for each project.

But ofc, it depends on what one means by "properly" applied. For most poser characters, the character will have different proportions from the person captured... different length legs = footslide, cos the rotation data at each joint is just copied verbatim, as FK keys.

Getting this proprtional correction into mocap is whats commonly referred to as retargeting, works instead by effectively placing out the "goal" points at the limb ends and so on, and then "reaching" the target character for these points in "character space".

There have been a couple approaches to this... for instance things that let you setup and manage these relationships manualy ,letting you retarget just about any character onto any other, regardless of structure... more flexible, but mroe time consuming... and other approaches whereby a standard rig is created, and all characters and mocap work off of that structure, making relating one to another highly automatable, adn fast. This is the approach taken by max biped bvh format, and fbx, which as well as being file formats, also use a common rig format for motioncapture transfer and retargeting.

Anyhow... what you will find is that LW gets along swimmingly with teh FBX format, which, unlike bvh, has a common structure used for skeletons and rigs, as well as the ability to contain geometry, weights, morfs, textures, etc, etc.

As long as skeletons have been named properly and the scenes have matched hierarchies properly, ull find that you can often just load and fbx motion straight onto a character with an fbx skeleton... however for a full and proper exchange all the time, ull want to spend a lil manual setup.

First make your "master" character in LW, with fbx style skeleton, weighted, skinned, etc... Send it out as fbx to an external app for retargeting.... something like motionbuilder, or for free and easy, animeeple. load and retarget your mocap onto the imported character... using either fbx, bvh, or other data formats as the mocap source... add/plot this to your imported character before exporting back out. In LW take your master character, and load the finished anim data back onto it from the finished fbx.

Once u done it a couple times, very easy... vids on the site, plenty threads on the forums here too.

Richard Hebert
09-11-2011, 04:49 PM
Thanks for the detailed and intuitive response. And yes... you are truly a Jedi Master! I was beginning to turn to the Dark Side... Anger, Fear, Frustration etc. You rescued yet another Padawan Learner.

Richard