topic Re: Mesh Rotation in MotionBuilder Forum

Mesh Rotation

Anonymous — Wed, 02 Aug 2017 17:56:43 GMT

Hi
I'm having a strange problem with my character mesh when I'm editing it' control rig
Every time I mark a key frame on his hand, his forearm mesh rotates a little bit

In my animation He is holding a gun with both hands so I'm using a parent constrain in both of them, with the difference the left one is using an Aux Effector to parenting (the one that rotates when I mark keyframes)
I don't know why this happens since I'm not editing his arm (or directly his bones)

The only solution that I could find to solve was to bake my animation to his skeleton and than rotate the arm back to it original position, the problem in doing it is that his hand also rotates and leaves it position...

I could keep doing this every time the bones rotates , but this takes a lot of time to solve
I want to know if there is a better solution to solve this or if this problem have something to do with my character mesh or Motion Builder.

PS: I had the same problem with his shins when I use butterworth filter to place his feet in place (without using the parent constrain or aux effector)

Re: Mesh Rotation

Joe.S. — Thu, 14 Sep 2017 19:58:08 GMT

I’ve had a bunch of similar issues with the HIK solvers. Try switching to the default Motionbuilder solver and see if you get the same results.

Re: Mesh Rotation

Anonymous — Fri, 29 Sep 2017 20:51:33 GMT

yup still with the same issue 😞

Re: Mesh Rotation

jps — Thu, 05 Oct 2017 19:59:06 GMT

It's most likely the way your skeleton has been characterized and the character parameters.

1-Are you using dedicated bones in your skeleton as roll bones?

-If no, make sure in the "Character Setting" that "Roll Mode" is set to "Absolute" and all available inline value are set to "0".

-If yes, make sure they are characterized in the InLine or Leaf character definition and parameters of each roll is correct.

I highly recommend to rig your own roll bones and not use the roll params from the character as it tends to fail when dealing with character animations loading, retargeting and split body story editing.

2-If the characterization is correct, it can be possible that you have extra rotations on your ForeArm.

One thing you can try is to limit your rotations on your skeleton and just keep one axis of rotation on your elbow.

In a similar way, you can set limits on the FK controllers of the control rig. You can try to use "Kill Pitch" param from "Character Setting" -> "Modifiers" but

But in some cases and depending your animation pipeline, it might cause character animation loading / retargeting troubles.

3-Check "Elbow Reach" param from "Character Setting" to ensure a better animation retargeting. This has to prior animation editing.

Re: Mesh Rotation

Anonymous — Fri, 06 Oct 2017 16:33:47 GMT

woooooooooooow thanks a lot!!!

The problem really was in the "Roll Mode" menu. Just changing it from "Relative" to "Absolute" solve it (luckily)

Re: Mesh Rotation

W9168306 — Sun, 19 Feb 2023 17:55:38 GMT

Hi bro

i didnt follow any tutorial ,but i just think about it ,and i think i got the same way like u to solve this problem ,I think you are as talented as I am!!!!!!!!!!!

Thanks

Yang

Re: Mesh Rotation

W9168306 — Sun, 19 Feb 2023 18:16:06 GMT

Hi Konychan

Hi , i saw your solution for all , i think the first step can fix most of problem , that's should be really helpful ,thank you so much !!But would u mind me to ask more question about those point ,could u make more sense with characterized is correct. And what is my own roll bones and roll param ,and how to check "Elbow Reach" param,when it will correct?

1.-If yes, make sure they are characterized in the InLine or Leaf character definition and parameters of each roll is correct.

3.-Check "Elbow Reach" param from "Character Setting" to ensure a better animation retargeting. This has to prior animation editing.

Thanks

Yang Ge