Pose Editor World Space Issue

[kellykw]

Hi there,

we've been running into an issue wherein the pose editor appears to be activating blendshapes on a rigged character in world space instead of the controls local space.

We've set up a character with a corrective blendshape set up on each shoulder.  Each blendshape has four targets one for foward movement, one for backward movement, one for up and one for down.

The arm setup is a simple IK FK scenario with three arm chains (FK, IK and bound) linked by blend colour nodes via the rotation channels.  The mesh is skinned to the bound joints with IK and FK acting as drivers.

We used the bound shoulder joint to create the interpolator and then set the Fk shoulder control as the driver under the advanced settings and used this to create the neutral poses and active poses.  (however we also tried remaking it simply using the joint as a driver whilst trouble shooting and it also does not work)

If the character is in the neutral T pose, and we rotate the characters shoulder forward using its FK_Shoulder_Control, the individual forward target activates, this is the correct behavior, the same goes for  arm up, arm down, and arm back.

The problem occurs when we rotate the character from the waist forward to, let's say 90 degrees, (so he is bent forwards) then if we try to rotate the shoulder forwards (relative to the characters chest) the arm down blendshape activates, not the arm forwards.

We've tried replacing the blend colours with pair blends, setting all of the poses to swing only, turning on independent rotation in the advanced settings and typing in rotation cap values, tagging the controls etc and nothing has helped.  

Below are screen grabs of the issue.   At this point any assistance would be greatly appreciated. Thank you

[sean.heasley]

Hi @kellykw

This is a bit complex and I'd like to see the scene file to get a better idea of what's happening.

When you get a chance, can you please zip and attach the scene file here or via dropbox/google drive or another file sharing program so I can take a look at it?

If the file is NDA or confidential in anyway please feel free to send it to me in a private message!

[kellykw]

Hi Sean,

thanks so much for getting back to us, I'm going to send you the file via DM now

[sean.heasley]

Hi @kellykw

Thanks for sending me the file!

Are you sure nothing went wrong when building all of these connections through blendshapes and poses?

I noticed even if you lock all the attributes and rotate the character forward the arm blendshape is still affected by it so it looks like they are linked in someway.

I'm having a few co-workers look at it as well to make sure I'm not missing anything but it seems to be an issue with your workflow and/or how the connections were made.

Are there any other rigs that are having similar issues?

[kellykw]

Hi Sean we've found that the issue seems to be that when rotated from the
COG control the arm joint chain is acquiring rotation values despite the
controls being zerod, we have triple checked our connections and can't find
anything amiss. The blendshapes are just highlighting the issue of the
joint chain rotation. Any help trouble shooting where these rotations
could be coming from would be greatly appreciated

[sean.heasley · Accepted solution]

Hi @kellykw

Thanks for that info!

Oddly enough, I opened this on my PC with 2018 Update 4 where is yesterday I was working from home and I tried your scene on Update 3.

Update 3 I was able to see the issue but Update 4 it's not occurring. What version of Maya are you working with and is it up to date?

If you are using 2018, can you update to Update 4 and see if this still occurs? It's possible this type of issue may have been an issue with Maya and has been fixed with an update.

[kellykw]

Hi Sean I just tested the scene in update 4 and you're absolutely right the
issue is resolved and the targets work when using a remapvalue node
channeled to their weights, we had wanted to avoid updating mid project,
but may just have to thanks so much for your time 🙂

[kellykw]

Hi Sean

After some more testing we found that the rig had some further issues and we thought that we would share the outcome in case anybody else can benefit from it - our rig setup was entirely modular for ease of duplication and alteration (with the arm, spine, leg etc hierarchies contained under individual nulls and then connected to each other via parenting or constraints)  It is the null groups that are causing the arm chains to inherit rotations from the COG.  The moment we stripped out the nulls and created direct connections between the limbs and the spine chain the arm joint chains maintain zero values when the torso bends forwards or backwards and the blendshapes evaluate as expected regardless of whether they are driven by remap value nodes or an SDK setup or through the pose editor.  The blend colours and blend parent nodes also work perfectly as a bridge for the IK,FK and bound arms as does the old orient constraint switch setup.  

[kellykw]

Also just a note we did find one issue with the pose editor - when using orient constraints between the IK, FK and bound limbs we found that the pose editor allowed us to double click a pose or a neutral position and the limb would assume that position, however as soon as we utilise blendcolor or blendparent nodes to bridge our IK FK setup, then this functionality within the pose editor no longer works - the shapes still behave correctly, but the ability to toggle poses by double clicking them within the pose editor is disabled.  (we have tagged our controls as such and set the controls as drivers, but this doesn't resolve the issue)  It's a minor thing and very easy to work around, but we just wanted to inform you.

[sean.heasley]

Hi @kellykw

Sorry for the delayed response I was out of the office friday.

I'm glad this worked out for you and you were also able to figure out what else was wrong with the rig. Thanks a ton for explaining what you did in detail and hopefully that will help any lurkers that may run into a similar issue !

[snake3y3s]

Hi Sean

Is there any possibility that you will let the software engineers know about the issue in the pose editor, that its not reading through nodes but works through constraints just fine.

What would be the fundamental difference between a constrain and a node for the cause of this?

[sean.heasley]

Hi @snake3y3s

I'm not sure what the difference is that's causing this but yup I've actually already made a log post on this with our dev team so they can look into it!

[Fox4445]

I can confirm there is still an issue with this, and have reported it to Autodesk who have now reported it again to their developers. Whether or not it is a bug or just a known limitation because constraints seem to work in worldspace, I don't know, but the fact is the modular style of rig doesn't always work straight out of the box with the Pose Editor. I have just switched from Maya2022 to '24 and discovered the Pose Interpolator deformations on the shoulder of my rig seem to behave properly now without crashing, so perhaps something has been fixed or is more stable but I still have issues at the wrist. If you have, say a hand joint constrained to the arm, in turn constrained to the torso, then the skinned hand joint will display the total combined rotation of torso, shoulder, elbow and hand in the outliner. The Pose Interpolator needs the relative angle of the hand to the elbow. In hierarchical joint systems this is automatic but in the modular/constraint approach if, for example, you rotate torso, shoulder and elbow by +20° in Z, the hand joint will show rotateZ= 60°. So the corrective deformations you might have carefully sculpted around the wrist in a T-pose will activate when the arm swings down next to the body, or up or back and forth, even when the hand/wrist is straight, causing an unsightly bulge in the wrist. It would be nice if Autodesk could implement some kind of 'relative mode' like clusters, so the Pose Editor either automatically calculates the angle of the constrained joint relative to the 'parent' or let's you plug in the parent, just as you can plug in a controller. In the meantime, I did sort of find a work around that uses matrix nodes to calculate the relative angle (see image for connections). If you then output these relative rotate values to a proxy joint and set up your Pose Interpolator on the proxy, then the Pose Editor has the correct angles to work with. Just make sure to select the mesh and choose 'selected' when you add an individual pose, because obviously the mesh is not skinned to the proxy joint. I say it's a 'sort of workaround' because in two different tests I did I had to connect different combinations of matrix connections into the MultMatrix node, or even reverse the inputs into MultMatrix, or multiply by -1.

Alternatively, this is quite good too Maya: Creating A Texture Based Pose Space Deformer on Vimeo