Motionbuilder : Up axis + rotating pivot

Tools MotionBuilder
#1

Hey all,

We are saving out a rig from Max to Motionbuilder by saving to FBX and then set the option of using the Y-Axis. This only changes the world axis and not the axis of the nodes. So all my meshes and bones have still the z-axis as the up axis.

Is there a way in MotionBuilder that I can change my bones + meshes their axis by using the y-axis as the up vector?

I did not directly found an option to do this in MotionBuilder. I did play with the pivot properties, but this only moved the pivot and did not rotate it.

So my next plan is to make a python script for rotating the pivots with 90 degree on the x-axis.

I wanted to ask your advice first because I just started with MotionBuilder and Python so every help is welcome.

Cheers,
Robbert

#2

[QUOTE=Nysuatro;13892]Hey all,

We are saving out a rig from Max to Motionbuilder by saving to FBX and then set the option of using the Y-Axis. This only changes the world axis and not the axis of the nodes. So all my meshes and bones have still the z-axis as the up axis.

Is there a way in MotionBuilder that I can change my bones + meshes their axis by using the y-axis as the up vector?

I did not directly found an option to do this in MotionBuilder. I did play with the pivot properties, but this only moved the pivot and did not rotate it.

So my next plan is to make a python script for rotating the pivots with 90 degree on the x-axis.

I wanted to ask your advice first because I just started with MotionBuilder and Python so every help is welcome.

Cheers,
Robbert[/QUOTE]

MotionBuilder doesn’t require you to have a specific local axis for the bones, just a specific world-axis when characterizing.
So if you just rotate your character´s root bone before you Characterize your character you should be fine. Obviously, you’ll have to deal with the data being in a world-space that is not the same as in Max also.

If you still want to get funky with manually editing the axises in motionbuilder, you can look into “Pre-rotation” and “Post-rotation”; but this will often pave the way to a world of hurt further down the line.

#3

Thanks for the response :slight_smile: