Please help to understand the file output of MotionBuilder

[Anonymous]

Hello guys & girls,

I have hired an artist to create character models for me. These 3D models have a skeleton and are fully rigged. I want to animate these models. So, the first steps for me were:

1. I opened the FBX file my artist made for me
2. I re-positioned some skeleton joints so that the model is in a perfect T stance
3. I create a Control Rig and assign the skeleton joints of the model to the logical items of the Control Rig.
4. I create a Biped skeleton
5. I add the Punch animation from the Tutorials in the Asset Browser to the scene.
6. For my created character, I use the Punchguy as Source

When I click on the play button, my character model punches. This worked perfectly so far. Finally, I saved my work as a new FBX file.

Now, my problems start: I do not understand the content of my new FBX file. In the original FBX file (the one I got from my artist), there were 80 nodes:

• a root node
• 3 meshes
• 72 skeleton joints
• 4 other nodes

In this original file, there was no animation information!

In the file written by MotionBuilder I have 293 nodes:

• 3 meshes
• 144 skeleton joints
• 135 markers
• 11 other nodes

I have the same skeleton joints as in the original file, but for each old joint I have also one new joint with names like "Skeleton_v75:RightHandMiddle1". 

In addition to a lot of new nodes, I also have data for a single animation stack with 217 key frames. The Punch animation of the Punchguy asset has also exactly 217 key frames. So, this seemed fine. However, when I import this FBX file into my video game (using my own game engine!), I see my model in the perfect T stance when animating it. All 217 key frames contain the information about the T stance and not of the Punch animation.

So far, I retrieved the key frames of an animation by getting the clusters of a skin deformer. For each cluster, I get the affected joint's control points and calculate the vertex transformation for each of them. This worked perfectly fine so far for all the animation assets I bought so far.

My questions:

• What are these new joint and marker nodes? How do I use them?
• How do I get the actual animation of my model?

[Anonymous]

Is there no one who might have a hint for me? How do you work with the FBX files you created with MotionBuilder? Anything would be helpful for me.

[jps]

That looks normal as you added the full scene from punch animation to your current scene. So you have now much more things into your scene.

One thing you could do when you retarget animations is, to save character animations from your retargeted character.

When all your retargeted animations are saved as character animation, you can load them onto your freshly opened rig file so you just have your character.

[jps]

One other thing you should consider is the use of namespaces to avoid name increment in your hierarchies when you start a retargeting task.