shifter_classic_components: S_Spine and Neck bad end scaling

[miquelcampos]

reported in the forum http://forum.mgear-framework.com/t/s-spine-and-neck-bad-end-scaling/570

[tokejepsen]

Here are the two reproducible scenes:
reproducibles.zip

It might be an issue across all components. Its basically when you make spines/necks for quadrupedal characters, where the spine is pointing towards the world z axis, rather than y axis.

[tokejepsen]

Sorry those reproducibles were slightly wrong, as they were pointing in the world x axis. Here are an update spine maya scene, but the issue the same across all components using the mgear_squashStretch2.
Initial research looks like its hard coded to the y axis.

s_spine_reproducible.zip

[tokejepsen]

BTW I'm looking at making a PR now.

[tokejepsen]

I've done some tests and its seems like no matter which direction the components are facing, its always turning the mgear_squashStretch2 to z axis that solves the issue.

This is unfortunately beyond my knowledge of mgear and Maya to look into the node itself, so I'll leave this up to someone else to feedback on.

[miquelcampos]

@tokejepsen thanks for checking this and feedback. I will try to go over this ASAP. Probably tomorrow

[miquelcampos]

Hi, @tokejepsen Not sure if I doing something wrong but I can't reproduce the issue or I don see it :P .

in this test I have 2 rigs one with scaling in 2 axis and another build to scale uniform in 3 axis using the z axis. This option was meant to be used for game export that doesn't support non uniform scaling

You can see the difference in the middle parts

The skinning is not smooth. So I can see clearly if the parts skinned 100% to 1 joint have any shearing. Maybe is that?

I will remove this issue from 3.2 release. But keep it open for further research

Thanks,
Miquel

[tokejepsen]

Hmm, very odd. Here is a scene where I've got two s spines; one with uniform scaling and one without. Non-uniform scaling has some issues with the end where the deformation is sheared.

bad_scaling_reproduible.zip

Having uniform scaling does seem to fix the issue.

[miquelcampos]

@tokejepsen
Just open your scene and screen capture:
EDIT: image front view

Maybe this is Maya issue? I am using Maya 2018.6 on Windows

[tokejepsen]

That is peculiar. I'm on Windows 10 and Maya 2019.1

[miquelcampos]

I will check tomorrow in 2019.0 (I don't have 2019.1) But maybe is a Maya regression