Web Questions and Answers for Autodesk MotionBuilder

Between running Rigging Dojo and other things I have been trying to checking in with the questions being posted on various forums for MotionBuilder.

So here is a quick compilation of answers to issues that have been showing up.. hope it helps others as well.

• How to limit constraint effect across multiple takes?

  There is a setting under the animation/keyframe menu Take options, normal or muliti
  select the constraint. set it to 0 first. Then select the constraint only in the navigator and change the take setting form normal to multi take, so that its settings save per take.

• How can I rotate my Animation with out having to us story or other hacks?

  Use the move keys tool.
  First hit the unpin all button, rotate your character to the new direction, but instead of adding an animation layer, just select all the keyframes in the timeline and hit the move keys button. It will update the translation keys based on the rotation allowing you to redirect the character.

• How can I update geometry and skeleton in MoBu? (MotionBuilder)

  See past blog entry http://motionbuildertraining.blogspo...ting-with.html on updating with out having file referencing like Maya.

• How do I retarget prop animation or motion capture data in MotionBuilder?

  It just depends on how your trying to retarget the data, Props require a mix of custom rigging and offseting, most of the time I can just do it with basic constraints.
  http://the-area.com/tutorials/props_editing (have to log in,free) but it covers the basics, although not one of my best demo scenes:)

• MotionBuilder - Batch tool - Char has no reference ,error message?

  This is because the skeleton is missing a top node above the root, it can be a null or anything above root. Uncharacterize the "character node" then drop the new null/node in to the reference slot in the character settings and re-characterize.

• If I have a set of animation files,Is there an easy way I can characterize these animations without going in each file, and still preserving the file name?

  You only need to characterize the skeleton once.. in a Tpose then import all the non characterized animation files on to your characterized skeleton, in to takes all in one file.(each take should have the file name)
  Then do an export to one take per file, useing the take name from your file as the exported .FBX file name and that should work.

• Takes – Merging key data between takes

  The fastest way to do combine or put two animations that live in separate Takes together on one take...simple select the animated object, CTRL C to copy, switch takes and while the object is still selected, CTRL B, This will let you do a paste special and past the animation quickly.
  The other option is to select the animated object and then select the range of keyframes to then copy and paste, in the main timeline. This lets you pick only a small portion of keyframe data instead of all of it as CTRL B would do.

• Bugs found in MotionBuilder 2011-

  Take order after reordering in the navigator is not saving, no fix currently
  Macros in Relation Constraint does not correctly save/reopen if the macro is in any other node but the first constraint created. (Fixed in the 2011 advantage pack"
  Extrapolation for keyframes , doing loops etc, does not save correctly and reopen-Workaround you have to bake/plot the keys on a layer to make for easy editing/updating with changes.

Hope this helps some people out, and Fan/Like the Rigging Dojo Facebook page for future surprise question and answers live by myself or other RD guys where I will take MotionBuilder questions live and it will be free.

Tutorials: Physics Ragdoll with joints and Python tool

KXL has done it once again, this time a fantastic video and script you can find here: Physics video - Ragdoll with joints AND Python speedup

He included a new python script for MotionBuilder and his video covers, Tails simulation, characters on a ropes,hair and python for physics ( a new tool that puts all the needed settings for simulation in Motionbuilder in once location!!!! YES, so needed.)

For all the people having trouble with the new 2010 and 2011 Joint tools in Autodesk Motionbuilder the new python script and video will be a huge help.

to see more examples you can check out my previous post on his other great videos

Tutorials : MotionBuilder Physics

Tutorials : MotionBuilder Physics

People looking for physics tutorials in MotionBuilder read this post:)

First you can read over my post here on a hack way to pin a ragdoll for older versions of MotionBuilder.
It is one of this blogs top links but there are much better ways to do these things now.

Also if you register for http://area.autodesk.com (free) you will be able to
log-in and watch my web masterclass on MotionBuilder physics

->MotionBuilder Physics: Ragdoll Tricks for Production <- to go to my original post here on the blog to find the link to the video and more information. Now thanks to the amazing "KXL" (he not only programed the physics tools for MotionBuilder he is doing free video tutorials, can't get better than that). You can log in to Autodesk Area and go to this thread Next Physics video poll where you will find the links to below videos covering
the following topics for MotionBuilder and vote for what you want to see next.
(he does this on spare time so thank him! and don't complain there is no audio)

Physics videos for MotionBuilder:

- Solver basics
- Rigid bodies basics
- Joints
- Setting up ragdoll
- Rider setup (part 2 for Joints)
- Little about Animation Mixing
- Animation Mixing


They are all full of fantastic tricks and tips for all kinds of really cool stuff like setting up a car to adjusting the settings to get great playback and correct solving.

Hope you all find this helpful!

:)

TIP: Path animation for characters in MotionBuilder

For some one that wants or needs to have a character walking follow along a path in MotionBuilder as my friend Kiel Figgins shows in Maya http://www.3dfiggins.com/tuts/MoPath/.

There are a few times where this could be very helpful for background characters or when trying to deal with uneven ground and should give you an idea on how to approach controlling the character with a story clip and cycle. Make sure to read over Kiels tutorial to understand the details.

*note the video has no audio, showing proof of concept and the relation constraint settings at the end.

LINK:Video.swf of the Path Animation examle

In the video is an example of hooking up an FK skeleton on to a path and having it follow along a curved path.

Download : Sample File for MotionBuilder

If the Path and Story are giving you trouble or you find you don't need a complex solution, here are a few other ideas and tricks on how to control motion direction over and around surfaces.

1. Chop the cycled clip in to chunks and rotate each chunk and blend between them so the character walks around the corners, each clip controlling over all direction and Blend.

• For a cleaner edit Animate a Turn/lean move, make one clip, mirror the motion, make another clip and use that to blend between the walk cycle clips much like a game would.

2. Bring it out of story in to the take. First cycle the clip and then bake it to the fk skeleton in the current take. Then you could constrain just the forward direction of the hips to the path

• You could also plot/bake it to a control rig, cycle the character in place (button on the character controls) and plot/bake, now you have a FK skeleton walking in place that you can map to a path node .You can also use the time warp in Fcurve to help adjust speed of the walk along the path based on stride length.
• Leaving it on the control rig (if you want to use IK you will have to make a custom hiearchy with the control rig (shown in the DVD) and adjust reach settings to allow for the rig to follow the path. Doing this you might be able to use the foot L and R floor objects and animate them along a path or just key them so that the ankles and feet match the angle of ground the character is walking up.

3. Like example 2, plot to the scene, on the control rig or fk skeleton , with out the path and use the “move keys” tool and regular manipulation of the character to rotate the animation in the direction you want, select the key frames from the turn forward and hit. “move keys” you can do this for each turn. If you do this on the control rig you can adjust the feet ctrls easier to help with the turn transitions.

All that said creating or capturing the correct move list you need is the best solution, while not always possible.

Shortcuts always look like shortcuts, to many of the same walk cycle, to much walk down spline, turning with out taking the “turn” in to account in the motion, auto walks, etc.. all just end up when left as is, producing “computer movement’, so be aware of it and you will be fine:)

Brad

Class Excerpt: Skinning Updating with out file reference ability

I have seen this question pop up a few times now and figured I would share this from our eDVD.

Currently Autodesk MotionBuilder does not have true file referencing ability and this would normally cause lots of problems when it comes time to update a rig file or lots of animation files. The lucky thing is that MotionBuilder has a very robust and configurable import and export system that allows us to create new files very quickly or update old ones.

Skin Update and or Blendshape update:

First open the file you want to update then

1. Go to File >Merge and pick the new updated file that has been fixed in some way, skin weights or joint alignments for example.
2. We will set the options for the merge
   
   • Right click on Element and set it to Discard All
   • Click on the square next to Models until it shows a circle of arrows
   • 
3. Models are now set to merge meaning that MotionBuilder is not adding any thing to the file just replacing the matching object it finds in the scene with what your loading in. Iin this case the skeleton/mesh/weights etc. anything that is considered a model)
4. When it is done you should have the updated character, still characterized and with any motion edits etc you have done in the file playing back correctly.
   
5. Note that there is a bug where this operation removes the objects from any groups they are in and they will have to be added back in after the update.

There are other work flows to create updated files but this is a fast and clean solution that I have used a lot. This also works with more complex changes like skeleton adjustments , LRA, rotation order, position, etc done in Max or Maya but be aware that you would want to re-characterize and rebuild the control rig after doing an update where joints change so that the rig updates itself. This is still faster than having to start the file over from scratch.

LINK: Area Blog post :: Maya <-> MotionBuilder workflow demo (part2)

The Area :Blogs : Maya; MotionBuilder workflow demo (part2)

Steven Roselle has posted the second part of useing Maya with MotionBuilder.
Thanks for the MotionBuilder love.

* I ,Brad, have been buried under a bit of work including lots of time contributing to the next possible future releases of certain software, or in Alpha test land. I hope people are still getting value and use out of the Toolkit DVD.

Also in other news- Digital-Tutors has MotionBuilder Training available as part of the subscription service, great if your all ready signed up. It is currently basic looking stuff that is good to build upon but there are still free resources available from Autodesk on the Area that cover most of the basics and plenty of advanced topics (that I have created and linked to here on the site). Either one, I am glad to see more traning available for MotionBuilder

Tip: Constrained Ragdoll in Motionbuilder 2009

***Update***
In MotoinBuilder 2010 you can now use real dynamic joints and also animate the state of the ragdoll solver on and off to allow you to setup this kind of grab,drag,throw action without this hack.
***end Update***


Just a quick note, if you are new to Motionbuilder 2009 (Mobu), they added a basic Ragdoll solver and some new realtime physics tools that you can put to use If you have not used the new tools, the helpfiles do a good job of going over how to setup and use the new solver. Also a quick plug I am working on another video tutorial for http://area.autodesk.com/ that will cover more MotionBuilder physics tircks and ideas on how to use them for production. ***find the post on that tutorial here motionbuilder-physics-ragdoll-tricks ***

I wanted to post this here after seeing this question. over at cgtalk.

1. What you want it to follow must be animated all ready
2. Constrain the Ragdoll node (hand for example )to the animated object ( I used a position constraint )
   
3. Turn on Record ( turn off live in the physics solver)
   
4. Select the ragdoll object before you hit playback
5. Click play and you will have your ragdoll following the animated object it is constrained to.
6. If you want it to let go of the constrained object while playing back.. just double click in the scene to deselect the ragdoll obj. and it will let go of the constraint and do a full solve.. like being thrown by another chracter or dropped from a plane or thrown from a car.
   

While not yet as powerfull or "smart" as something like the Natural Motion products, there is something to be said for having a system like this built in to MotionBuilder where the artist is all ready working with the eidting tools and NLA animation tools.
Brad

Tip: Custom Properties in Motionbuilder

There are actually going to be a few tips for MotionBuilder based on this thread over at the Area. Custom properties are very powerful in MotionBuilder and here are some tips on working with them.

Problem: (Custom Properties range)When useing the MotionBuilder Character face the sliders that are created only go from 0 to 100.

• Fix: The Face expressions that get created are just custom properties and can be edited with the property editor (properties window->customize->custom properties). Here you can set them to be -100 to 100 or what ever value you want.
• Fix: Instead of editing the existing custom attributes (custom properties) it would be best to add your own on to an animation control where you can blend the expressions so one slider controls the opposite shape. You can also drive them with viewport based controls like Jason Osipa shows in his "Stop Staring" book useing relations constraints and control objects.

Problem: (Custom Properties Organization) While you can create custom views for objects to selectively show some properties and not others, this does not work when your trying to filter a list of custom properties. For example 100 face shape sliders would all be one long list, yuck!

• Fix: Here is a quick how-to video. (make sure you make the folder under the “character face” as I did in the video or they will not show up. The basic idea is you create a custom view for the properties and then you can add folders to the main category for the properties and then move them in to each new folder to clean up the long list.

  Click to watch: Folders in custom views for MotionBuilder Custom Properties video
  

Problem: (Custom Properties story and posing) If you have created a lot of custom rigging or useing the MotionBuilder Character Face tool you need a good way to both store them as poses and be able to have their animation load in to the Story tool to do blending, cycles, etc.

• Fix: Character Extensions allow both of those issues to be fixed. In the case of the Character Face tool, you can drag its auto created expression sliders on to the Character Extension those attributes will now work in story with the main character track.
  
• Fix: Extensions also work with the pose tool allowing the pose tool to store poses for any other objects or properties(attributes) that the character tool needs to work with.
  

Thanks to Keo Heng SCEA Bend Studio for asking the questions, glad to help.

*Solutions like this are covered in our Masterclass. When you find you need more detail or a deeper understanding of how to work with MotionBuilder check out the class DVD and 100+ pages of step by step tutorials and videos.

Prop retargeting tutorial: Up on Autodesk Area webiste

The second MotionBuilder 2009 tutorial is up on The AREA, this one covers prop editing and retargeting.

The Area Tutorial: Props Editing and Retargeting

Brad

Tip: Synced Zooming

I am not sure how often this will be handy but I don't think it is known to very many people.
It is handy some times to be able to zoom or pan all the views you have open at the same time.

Watch the video and you can see that clicking and useing the view hotkeys like shift and ctrl on the view pane split will let you do this.

Story Loop tutorial: Up on Autodesk Area webiste

A gift for 3December

The Area Tutorial: Looping and editing with the Story tool

The first tutorial for Autodesk is up on the website The AREA, it covers how to use the story tool to take a motion capture segment, trim it, align it to go in a strait line, blend it between clips and finally do a offset pose blend to create a seamless loop that can be used for a game or in other parts of story.

The scene files are included for download so you can take a look around.. This is done in MotionBuilder 2009. (There is a free trial of it out now for download)

Feedback is very welcome. leave it here or on the Autodesk site.

Brad