fbx animations lose at import if under parent in hierarchy

Unity Engine
1

Hello,
I’m working on 3DSmax: I’m building a construction with walls, grounds, doors, etc., AND some animated objects inside like industrials machines.
I export sections of my 3DSmax scene in .fbx and put those in “assets” folder to use in Unity.

The hierarchy is (I specify if the elements are animated) :

  • construction (an empty node called “dummy” in 3DSmax)
    – walls
    – doors
    – grounds
    – machine A
    — animated part 1 (animated)
    — crankcase
    ---- animated axis 1 (animated)

Now here is my problem : if I export the entire hierarchy, Unity don’t see any animation in the model.
I tried to re-import .fbx in 3DSmax : animation informations are right there…

I tried to export a .fbx from lower in the hierarchy => if I export “machine A” and his children, then it work : Unity see the animations.

So my question is : is there a reason for this animation informations are lost ? Or am I doing a wrong manipulation?

Thank you very much.

2

I’ve never attempted this before so I can’t suggest an exact fix.

Are the models coming in as one complete model with correct hierarchy parenting (set in Max) as separate sub-meshes?

Since the 6 or so levels above the animated elements are not animated, is it important to keep this Max created hierarchy in the export?

Why not just export the animated elements separately - so they have there own animations and the fbx isn’t messing up the transfer into Unity?

Optional test. Set animation keys on all the elements over the time frame the animation takes place on the animated parts. So set animation keys on construction, walls, doors, grounds, machine A etc. Even though the pieces will not move, the key frames will be set so all the elements have animation keys - and the ACTUAL animated pieces should work properly.

The other option that WILL work is to import the animated pieces separately and set up the hierarchy in Unity instead.

3

Hi theANIMATOR2b,
Thank you very much for your reply !

I understand it is not easy to inquiry without the real scene, so I just wanted to know if there is a knowed problem look like mine.

The all models are coming with correct hierarchy parenting, no problem.
The hierarchy do not have more than 3 children.

I have tested put keys on every objects, even the static ones, but the result is the same.

In first I didn’t want to export each animated object independently to reduce the number of export actions and assets, but I will do it because I don’t see other choices and I have to go ahead.

Thanks again

4

I’ve read a couple instances of people (usually mechanical animation that do not use bones) having problems with animated components deep in a hierarchy.
I can’t remember if those people found solutions to the issue, although importing animated pieces separately seems correct.
Consider using a proxy placeholder object (dummy or null) in the static export in place of the animated object. So when the animated piece is imported into Unity you can align the animated piece exactly to the proxy object.