topic Skinning difference between 3ds max and motionbuilder in MotionBuilder Forum

Skinning difference between 3ds max and motionbuilder

petecmartin — Tue, 14 Mar 2023 09:17:43 GMT

Hi,
I've done a dress simulation in 3ds max and created a skinned rig of the simulation via 'dem bones'. The result in 3ds max with 100 bones looks fine - when I send it to motionbuilder the mesh look all jagged and screwed up.

I've tried a few things - no parent for the bones, a parent at 0,0,0 and parenting them via the character heirarchy but I still get the same result.
I've managed to get the same mesh to work by point cache in motionbuilder, it's just when it's a skinned object.
Any ideas anybody?

Re: Skinning difference between 3ds max and motionbuilder

Frommynator — Fri, 17 Mar 2023 22:48:41 GMT

Hey,

Have you tried messing with the skinning settings in the system tab? Could possibly help.

Re: Skinning difference between 3ds max and motionbuilder

petecmartin — Sat, 18 Mar 2023 06:32:19 GMT

Thanks for the reply.

I may have had a brief nosey at the profiling centre. I'll take another look as maybe there is a default bone limit in mobu which would cause the same sort of issue.

Cheers.

Re: Skinning difference between 3ds max and motionbuilder

petecmartin — Sun, 19 Mar 2023 19:27:26 GMT

Hi,
Had a play with the profiling centre and system setting - I can make it look worse, lol! Unfortunately not better 😞

Re: Skinning difference between 3ds max and motionbuilder

kirbysteele — Fri, 31 Mar 2023 13:16:59 GMT

Hello All,

I've just come across the same jagged skinned topology issue in Maya, and after doing some experiments with a coworker we think that it is the renderer in Mobu clamping the weights of the mesh to .01. The experiment that we did was to make a simple plan in Maya and bind it to two joints and clamp the skin weight values to see if we could get a visual match. You can see when the skin weights have values to .001 in Maya the topo is deforming smoothly, but when you clamp to .01 it starts to get jagged. I believe that the actual skin weight information is still there in Mobu because if you export the model back out of Mobu it still deforms correctly in Maya. It is just that the renderer for the viewport is probably optimizing for performance. If this is the case, if Autodesk could expose the clamping as a parameter so it could be adjusted as needed, that would be very helpful.

Re: Skinning difference between 3ds max and motionbuilder

damian.pajda — Sat, 01 Apr 2023 07:37:15 GMT

please try if this helps:

1. double click the model in Navigator to show its options on the right side of Navigator

2. find Accuracy column and set value to 100. In my case it was set to 50

*You could also double click on main Scene element in Navigator and set this Accuracy for all models in scene

Example:

Default 50 value:

Accuracy set to 100:

Re: Skinning difference between 3ds max and motionbuilder

petecmartin — Sat, 01 Apr 2023 10:43:36 GMT

Genius!
Thank you for that, that's exactly what I was after! Brilliant 🙂

Re: Skinning difference between 3ds max and motionbuilder

jps — Tue, 06 Jan 2026 16:19:41 GMT

You can edit your config file to change the default value:
C:\Users\USERNAME\Documents\MB\202X\config\COMPUTERNAME.Application.txt
Search for "DeadWeight "

[Weighting]
DeadWeight = 0.001 ;Weights under this value will be removed (%).

Setting lower value like 0.001 will get what you are after.