Ghosting of imported 3ds Max skeleton will be on the incorrect axis using Motion Blend

Issue

When you import a FBX skeleton from 3ds Max, it will not display ghosting correctly when used with Motion Blend. This issue is apparent under the following conditions:

1. User has exported Biped character or skeleton hierarchy from 3ds Max to FBX with option set to Y-Up conversion from:

FBX 2009.00 and newer

Advanced Options > Axis Conversion > Up Axis > Y-up

FBX 2006.11.2 or older

Coordinate and Unit Conversion: > Conversion Method > Convert Animation > World Coordinate System Up Axis > Y

2. Character Skeleton has been imported to MotionBuilder with File > FBX Plug-In Import.

3. Character Skeleton has been added to Motion Blend for editing by Alt + dragging the skeleton into the Motion Blend window for editing. From Window > Motion Blend in MotionBuilder, the ghost of the skeleton will appear to be rotated +90 in X-Axis and it is still using the Z-Axis up.   A screen shot of the issue is below for reference:

Solution

This issue is caused by the FBX export from 3ds Max carrying transformation history. Even though the user has explicitly specified that the up axis be converted from Z-Up to Y-Up, the ghost display of the skeleton in Motion Blend mode within MotionBuilder will display the original Z-Up from the 3ds Max source scene.

A workaround is to use the Add FBX_root Node Conversion Method from the FBX 2006.11.2 exporter.  This workaround will not work with the FBX 2009.00 exporter because this option is no longer available.

Although Motion Blend is still used by some MotionBuilder users for Non-Linear Blending and editing of motion clips, this workflow has been replaced by Story Mode. It is recommended to use Story Mode instead of Motion Blend because it includes additional and improved functionality for users wishing to work with animation clips in a Non-Linear editing environment.