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  1. #1
    Join Date
    Feb 2011
    Posts
    3

    Multiple bvh's in MotionBuilder

    I have downloaded those 2,5k+ free bvh converted for motionbuilder (which means that namespaces are already there. I haven't found any concrete way to import them and use them as different tracks for the same character.The only way i know is through Story but you have to characterize each first.

    The process i use is like:

    Import Bvh
    Characterize it
    Plot it with control rig
    plot it to skeleton
    delete unnecessary tracks
    save it as .fbx
    and then import it in the Story of the character i want to animate.

    But I'd like to know why, since MB natively supports bvh , bvh files i use already have the correct namespaces , I cant just drop the bvh inside Story mode(without characterizing first and saving each one individually)and just work?Except the way i use(read it somewhere) is so wrong.

    Any advice on that would be much appreciated....

  2. #2
    Join Date
    Mar 2002
    Posts
    7,121
    I should do a video but on the other hand it really is something that is simple to do considering handling large amounts of motion capture is what Motion Builder was designed to do.

    There are 101 ways of approaching the need for MC management based on the cyclic nature of Motion Builder and as you have noticed dropping key frames into the story line can be done in a few different ways based on a need rather then being restricted to a single work flow.

    Primer.

    Perhaps the most frustrating thing about working with mocap, BVH, is the non-standard naming convention used by some mo-cap studio that makes it difficult to target the incoming BVH to the right “rig” which in most cases is referred to as the “model” and most times does not included the base t-pose “model” required in Motion Builder to have the model in the forward Z direction and in the t-pose position.

    9 times out of 10 you can select the entire BVH rig, delete any keys plotted to it, and zero out the rotations to obtain the t-position needed to Characterize the BVH rig.

    Selecting the root nod you can then import all of the clips that you need from import and if you select more than one all of the clips you selected will be imported to the same hierarchy and placed into “takes” contained with in the same “model”.

    So you can have say one “model” with 20-30 clips contained in “takes”

    With the animation in takes you can then insert just the take and blend it in story and either plot it to a new take or to a different character.

    So to answer your last question there is no wrong way of doing it but there is the ideal of the less efficient way if your looking at a collective of motion captures files as part of a library.

    If you’re looking for a starting point on how you can effectively work with BVH files as a collection then understanding the importance of “takes” should be your first step.

  3. #3
    Join Date
    Feb 2011
    Posts
    3
    well thx for your reply.

    I know about takes . What I was wondering is that while I have 2,5k MotionBuilder ready BVH's (with ready I mean : 1st frame always in T-pose and hierarchy namespace is ready for MotionBuilder ), when you just drag and drop a BVH on a character it says something about "X models on scene , Y models in file , some models not found etc." . I mean since they are READY for MB why it just can't get that the same namespace of bvh matches to the same of your character and you have to characterize and plot EACH bvh...

    But from what i see , you claim that if you characterize the first one only then the next you import it applies itself on a different take of the SAME character? I recall that I have tried this and it didn't work that way. Maybe I'm wrong I'll give it a go.Do you have to do something with batch too?

    Look , I'm just an enthusiast that downloaded MB in trial just to mess with it and see what it is... I don't know how I would have reacted if I had paid some thousand's of dollars and I couldn't find ANYWHERE in the manual or the Autodesk fora how to effectively import and use bvh's . Maybe if I had the full version paid they would provide that kind of support if i asked them. I don't know.I was just wondering... Thx for your time again...

  4. #4
    Join Date
    Mar 2002
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    7,121

  5. #5
    Join Date
    Feb 2011
    Posts
    3
    I just watched the video tutorial. It was nice and i think it should be added to your page at tutorial sector...thanks again for your time...

    But another question arised... You say that after you plot the whole animation to a new single take, then you can save that animation and import it once again in your target character.

    Would you mind clarifying the workflow of that there , because every single time I have used that option ,animation just plays onto its own without driving the main character or MB triumphantly crashes. They only thing i have found to be working is the one where you import the whole file and then select it as an animation input to your main character.
    if you have time to still deal with my annoying questions then you may want answer that too some time....No big deal since the animation input way works...Just wondering about the other way for informational purposes...
    Last edited by pappas81; 02-12-2011 at 06:02 PM.

  6. #6
    Join Date
    Mar 2002
    Posts
    7,121
    Well if Motion Builder is crashing then it’s probably the very thing preventing you from doing what it is that you want to do so that problem would need to be resolved.

    Workflow wise I ended short of showing how to bring the clips back in on a different character, as that would have taken another hour video to demonstrate the different options. Unlike most closed loop animation systems once you have your data in FBX you can move stuff around between a lots of different applications or even save out individual clips to use in the story mode.

    Workflow wise, and since you already figured out the character input part, you could bring your character in first, import and set up the BVH character, and then and set your main characters input to the BVH model. Once you have established that link you can plot all takes to your main characters base skeleton or control rig and delete the BVH model.

    Personally this is how I like to work as to me it makes no sense to take BVH motion capture and convert it to native FBX as motion capture is not “that” refined and cleaning up an entire library is rather time consuming. Not to mention after a while harvesting what you need it almost becomes cut and paste like.

    On the other hand if you want to save sets and apply them to different characters then there is a few ways you can do it.

    One you can check plot all takes, leave the control rig activated and save the file as normal. You need to save the file with an active character because a scene file could contain more than one character model and by saving the file with an active character that will be the model used when importing takes into a different application. This though will save everything. Using the file feature on the character control panel you can import the animations from the BHV character rig onto new character model.

    Or

    You can use the save feature on the character control panel to save just the animations and control rig of an individual model and then load the animations onto a different model.

    This is how you would save out an FBX ready animation clip but seems rather redundant considering you can just drag and drop a take directly into the story time line with out having to save the clip first.

    Overall though just like how important it is to understand how takes work knowing how FBX works is an important consideration as it’s just not another file format but could be considered it’s being another application with it’s own learning curve.

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