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EPIC_leg_01 twist/flip problem

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#10

Hi @Miquel!
I’m using mGear beta 4 that I got from here: Release mGear 4.0.0 Beta 1 · mgear-dev/mgear4 · GitHub

I downloaded it on Tuesday 8/24 so I think it should be the latest, but I’ll double check and see if there’s any code changes I don’t have.

Thanks!

Ok, I checked EPIC_leg_01>init.py and it looks like I have the old values:

self.tws0_loc.setAttr(“sx”, .0)
self.tws2_loc.setAttr(“sx”, .0)

I’ll try changing them to .001 and see if that fixes the problem.

UPDATE:
Yeah, that looks like it fixed it! Sorry for adding unnecessary noise on the forum. For future reference, how do I make sure I’m testing the latest updates?

Also, I’m trying to learn. Why does changing the Scale X value on those two nodes stop the bone from flipping? I would’ve never guessed to try that.

3 Likes
#11

the beta in the link is from june 7th :stuck_out_tongue:

Great to hear that the fix worked :smiley:

2 Likes
#12

@Miquel, Hi!
New to mGear, and not sure if this is the right post, but I am having this issue as well with this version:

I am using the MetaHuman Z-up template, and the issue is with the twist joints on the legs, when twisting the ankle, the twist joints are twisting with the incorrect axis. Seems to be fine with the metaHuman Y-up axis.

#13

Hello @kelsiesgroth thanks for the feedback. I will check this ASAP :slight_smile:

#14

Hi. I know people are repeating this, but I also can’t stress enough how much I appreciate mGear. Thanks for all the work on the updates!

I also have a “twist” issue once I build the Metahuman template with EPIC modules. The elbows and knee joints are not rotating when using IK or FK controls. I can’t seem to figure out why this is happening. Maybe it has something to do with the metahuman RBF joints not following along, if I understand this correctly.

Here is the video demonstrating the issue

I’m thinking about creating a rig from scratch using EPIC modules and once I build it I would
constrain just the main limb joints since the metahuman asset file manages the RBF joints without any additional setup. I guess… What do others think?

Edit: I’m using maya 2020.4
Edit 2:
There’s actually an issue that I think is intrinsic to mGear limbs. The upper arm joint, for example, never twists in rotate X. I think this is why the Metahuman upperarm_l_drv is not twisting and the RBF joints aren’t following along. If I tweak the mgear_matrixConstraing9 Driver Rotation OffsetX, I get the desired deformation.
I hope there’s a simple fix and I’m totally mistaken. :sob:

2 Likes
#15

Thanks for the feedback and videos! I will check and fix that ASAP. Definitely, a bug I have logged it here https://github.com/mgear-dev/mgear4/issues/51

2 Likes
#16

manny_arms
manny_arms1157×870 2.77 MB
having a possibly related issue using the ue4 Y up mannequin template. On the right upper arms and legs the rotation of the joint isn’t coming through

#17

Thanks for the feedback @aripanzer I will be checking the this ticket in the following days :slight_smile:

1 Like
#18

Hello @vladzy I am working now on your ticket. And yes you are right. The issue is coming from the roll joint rotation distribution.

While the roll is correct to deform geometry is not good to drive the metahuman joints that already have his own deformation system
The workaround for the arm is to set the division to 0 that will force to use the full rotation on the first (and only joint of the upper arm)

2021-11-09_15h00_00
2021-11-09_15h00_001224×826 2.68 MB

I am checking now the legs, because I think I didn’t add this behavior to it.

In short when 1 or more divisions are added the roll will distribute the rotation, from the first to the last joint of the upper arm. So the first joint that drives the metahuman skeleton will not twist.
If the division is set to 0 we will force the first joint to twist.

I will update the leg components to have same behavior and update the auto-snap tool to change this option automatically.

2 Likes
#19

The ticket has been fixed :slight_smile:

image
image1006×1052 157 KB

1 Like
#20

Wow! :smiley: That workaround never crossed my mind!
Thanks a lot @Miquel

#21

RE: EPIC arm 01
When having 1 division in the forearm (0 for the upper arm), am I the only one who gets a rotation flip when rotating the wrist FK ctrl more than 90deg?
It flips at -90 and 270 in RX.

armTwistFlip

#22

Hello @alonza1
I will check that. Thanks for the feedback :slight_smile:

1 Like
#23

@alonza1
I have checked it. The flip should happen at 180 or -180. But not at 90.
can you send me your guide? Are you using the Z-Up or Y-up version?

#24

We use Y-up.
@Miquel your message clued me in that maybe there’s something I needed to rotate to reset the flip to happen at180 or -180. The arm blade offset was neutral at 0 (edge pointing down in -Y), setting it to 90 (so it’s edge faced in the -Z direction) fixed our arm twist flip to happen as you’d expect 180 or -180.

#25

Hi Miquel!
Thank you for the quick response on this issue.
When we can get release with this fix?

#26

I will do a new hot fix release next week
but if you need it now is in included in this tag https://github.com/mgear-dev/mgear4/releases/tag/4.0.4

#27

following up if there has been any headway on this

#28

Sorry, I didn’t do the release yet. I just want to squeeze a couple of tickets more before release it :slight_smile:

#29

sounds good! I just grabbed the latest, 4.0.7, and I don’t see the fix there