FBX skinning not coming through to Unity

Unity Engine
1

Hi All,

I’ve been running into this issue where my character’s skinning doesn’t make it through to unity.
The FBX survives a round trip in Houdini and apparently some other applications (although I haven’t been able to test this myself).

Houdini -

Unity -

You can see that the bone movement is coming across but not any skinning information.
Houdini support believe it’s an issue with Unity’s import process. I might have to try a previous version of Unity but I thought I’d check if anyone has any ideas here first.

Thanks,
Pete

2

did you ever figure this out? i am seeing the same exact thing in 2018.3

3

Gday! It’s working for me now but I can’t remember exactly what the fix was. I know the process can be a little finicky at first. Are you exporting from Houdini?

4

yes, i am!

5

Okay cool, try importing the fbx back into Houdini to check it is actually being exported properly. Or grab this one to check the fbx FBX Review | Cross-platform 3D model viewer | Autodesk

6

oh good idea, on re-import i am just getting a static mesh… i am just using the default settings for fbx, and i am pointing it to a subnet that has a geo node (marked visible) and a bone chain (all marked visible as well)

is there any extra steps? i did see some old posts about “baking” keyframes not sure if that is needed though

p.s. if i import with a FILE node i get a static mesh whereas if i use the fbx import dialog i get a hilariously distended ice-cream-scoop looking mesh that does indeed animate

7

Is there anything you could send me? I’ll have another look at my settings now. Also what version of Houdini are you on?

8

Here check this file out, it seems to work okay.
http://www.peterleary.com/ForumFiles/FBX%20TEst-4H91hwAXQj.hiplc

9

sure! thanks so much for the help… i’m on houdini 17.0.352… attached zipped-up fbx

4274815–382576–sunflower_rig.fbx.zip (70.5 KB)

10

interesting, that hip file works! time to A-B the crap out of things

11

Im using totally default settings there, the skinning is biharmonic, maybe try that and see if it changes anything?

12

so the only difference between our two files was that my input to the whole thing was a FILE node (sunflower from quxel) and yours was a tube… when i switched my a tube it exported and imported correctly! crazy! i wonder if it has to do with zeroing out the transforms when i originally imported my flower…

i’ll do some more digging but at least i know the defaults work as expected with a minimal example

thanks so much!

13

susan sarandon in a summer sarong, i feel like the biggest idiot in the world

i was importing my quixel megascans fbx like this:

/path_to_quixel/3dscans/plants_3d_serfjkl/var4/var_LOD**$F**.fbx

that is, they store the different LODs at different frames of the fbx, by changing that to LOD1.fbx the export succeeded

it is weird that it worked inside houdini just fine but breaks everything on export (even if the playback cursor is at frame 1 on export)… maybe i should file a big at sesi

thanks again so much, back to my regularly scheduled flower animation programming

14

Ahh cool, glad you got it all up and running again!
I noticed another thing, if i put any node after the deform it stopped working.
So that could be another thing to have an eye out for.

710×794 38.1 KB

1 Like
15

oh thanks for the heads up! i think there is a checkbox to force deforms even they aren’t the last-most node but i haven’t tried it yet

16

Ahh thanks, I’ll check that out!