Why is SPINE_DUMMY bone used in the example characters?

[fneill]

Why is SPINE_DUMMY bone used in the example characters? I noticed that is used after the spine bone and also there is a Left Shoulder_Dummy and Right Shoulder_Dummy used. Why and how are they used? Thanks for any info. :)

[Anonymous]

HI there:)

I would really like to help you but...when you say exemple character ?
Do you mean character from the tutorial?or just from the clipart?
Let me know which one and where you get it, and hopefully, I'll be able to help you better.
Because some characer have EXtraBone which are use with HIK 4.0 but not so sure what you mean exactly.
So let me know
I'll see what I can do!
Cheers:)

MC

[fneill]

Thanks for your reply. With MotionBuilder 2010 in the tutorials folder a couple of the characters have a Spine Dummy and Should Dummy bone. "ARAGOR" and "MIA" both have those dummy bones. Iam boning a character in Maya right now (for export to MotionBuilder) and was wondering should I put in those DUMMY bones? and what are they used for? Thanks again for any info.

[_KxL_]

I would say those are to prove that MB character (in particular retargeting and control rig) can work with skeletons that have extra bones (bones that are not mapped by character).

But I am not master or rigging ;)Lets wait for Brad's opinion.

Cheers

[fneill]

Yes, cant wait to hear from Brad. I have found other MotionBuilder characters now with those EXTRA DUMMY BONES. Sure would like to find out why they are there and what their purpose is. :)

[sublist]

http://area.autodesk.com/forum/autodesk-motionbuilder/autodesk-motionbuilder-2009/why-does-mobus-def...

[Anonymous]

Hi,

If you look at the setup on the sample characters- none of the Dummy joints are included in the Character Definition. Working with the Control Rig on those characters, the dummy joints rotate automatically when manipulating any Control Rig Effector that constrains joint above or below the Dummy in hierarchy—
For example:, when you translate LeftShoulderEffector- the LeftShoulder joint rotates to fit position of IK effector. The LeftArm_Dummy joint follows same rotation as LeftShoulder joint as it is child. The Dummy joints are not being animated on when working with the Control Rig Effectors- they follow rotations of parent Joints.

You could add Dummy Joints on Rig for a few reasons:-

1. To aid in placement of joints to fit character mesh or to modify how control rig works. If you look at the mia example character- using a Spine_Dummy joint between the Hips and Spine joint means that the ChestOriginEffector is placed higher up on the Character when characterized.
2. To refine Skinning on mesh- adding additional Dummy Joints would give you more detail on the skeleton for the mesh to skin to
3. For manual roll joints on skeleton- some users setup manual constraints for roll joints on character instead of using Roll in Character definition. This is one area you may need to create Dummy Joints on rig
4. For additional animation editing or export after plot. After Plot- you may need to map rotations or translations to other joints on the skeleton. For example, game engine may expect the data a certain way, which is one common use for adding Dummy Joints to character before Characterization.

Best Regards,

lee

[fneill]

Lee, thanks so much for that in depth response. Really helps. Iam doing alot of boning in Maya, then the rig in MotionBuilder. I have found a wonderful utility that takes those DAZ STUDIO and Poser characters (extremely high rez) and reduces them down up to 85 percent with not much quality loss at all. It is called VIZUP. I can take any Daz or Poser character and export it as a OBJ. Then I let VIZUP do its magic. Then I import in to Maya for quick boning for MotionBuilder. So your response on the extra dummy bones helps me with more understanding. Thanks again :)

[Anonymous]

growtheweb may i ask you something? when i import as obj character from poser to maya, character coems so small and i scal it how i want, but it may make any problem in character animation? or should i do any otherway?Oter thing also, character comes wit many tiangle ,is it making any problem in skinning or animation? I tried to clean up by hand but it takes long time and sometimes almost impossible to clean ,mesh needs recreate parts...how you do it? if you let me know i will be happy

thank you

[fneill]

Hi egeman, as I mention in my post I use VIZUP to reduce the polygons on my Daz/Poser to Maya files. Daz/Poser characters are extremely high rez. You can reduce the resolution in Maya using MESH/REDUCE but it seems to not work too well when I finally go to import in to MotionBuilder. However, VIZUP is a master at reducing Daz/Poser OBJECT files and keeping all the textures in tact. You do have to scale your characters when you get in to Maya but that does not effect anything when you do export to MotionBuilder. Vizup can reduce the rez on my Daz Poser characters 85 percent and not show much quality loss.

[BradClarkRiggingDojo]

The extra dummy joints also can be created or added when coming form diffrent software via FBX. Those sample characters are older files and when Exporting Max files "bone" objects that did not have end nodes would often get dummy joints auto created so you could see the visual link bone between joints.

And yes, what Lee Said are good ideas and valid also.


funny:

I had a second to read over the post and was surprised to see my name in a few places.

I have the forum set to RSS feed and he feed does not show the latest comment just that the entry has been updated, so I don't always catch them all:)

Glad I had all ready posed in that other thread, so my virtual me could respond:)

I have been busy with my MotionBuilder student on Rigging Mentor, recorded 3 videos today, is been like making a masterclass a week...fun stuff like converting Maya expressions to MotionBuilder relation constraints and rigging for reuse.

[BradClarkRiggingDojo]

Oh and I think Grow should post a video or blog/ area tutorial on working with poser and MotionBuilder, I am sure lots of people would find it interesting and useful.

You have been working hard on learning the tools and its been cool to see you so active in wanting to share and learn.

[nvnoor]

when i link the sample "mia" character to the mocab file as its sourse in HIK, thats what happens for the spine, it is not folowing but insted bending, is that becuase

the dummy spine joint?