Discrepancies between skinning in 3DS Max and Unity.

Unity Engine
1

Hi there,

I’ve come across a bit of a speed bump with reagrds to getting my character to deform correctly within Unity. I exported my character mesh and rig from 3DS Max 2015 as an FBX and then brought it into Unity. I have then compared the character in Max and Unity and within Unity I am getting some strange anomalies with skinning, such as vertices spiking outwards.

Ive had a long old browse and I have already taken into account the maximum bone limit for Unity and altered my settings in Max to match that (Skin Modifier > Advanced Parameters > Bone Affect Limit: 4 vs. Fantastic Quality setting in Unity with Blend Weights set to 4 bones).

I have played around with the mesh compression settings and optimisation on the mesh but this hasnt helped any either.

I have tried exporting the model with turbosmooth on and off, I have reset the Xform several times, exported as Ascii and Binary. What am I doing wrong?

2

Try to make the vertex weight more defined effected. Also go to under Skinning “Advanced Parameters” check the “Bone Affect Limit”. and change it to 4. Hope it helps.

3

A couple other helpful tips -

Unity (or fbx) requires the skin modifier to be the top most modifier in the stack. If turbo smooth is above skin this might be the problem.

If you are using twist bones these have to be baked since they are not directly keyed in Max.

Under the skin modifier - Advance Parameters rollout check Weight all vertices if not checked.

Remove all mesh compression on import in Unity.

4

Thanks for the responses guys, unfortunately none of these have any impact on the outcome. I have tried all of these with no success. I have tried removing the skin modifier and reapplying it to see if it needed to recalculate or anything like that, but I still get huge discrepancies.

5

Then maybe you scaled something before starting to animate.

Did you scale something else on accident? If a bone was scaled without the adjust bone tool - that might cause something.

Some screenshots of the mesh might help. Can you identify the vertices that are spiking?
Where are they located on the character?
This is usually the cause of non 100% weighted vertices or bad scaling.

6

yeah i also think scaling/rotation/quaternion could be a issue here, since none of this helped.

You can try to collapse the bones. convert them to keyframes. Under Trajectories