Current Bicep Flexion setup isn't very realistic--Proposal of new driver setup

[Jasper29]

Kind of trivial, but bothered me-- I have a proposal for improved bicep flexion drivers. I was checking through flexions earlier (in addon tab) and noticed bicep flexion is absent from there now. Went to shapekeys and was looking at the drivers and it’s output in the viewport and realized this current setup is VISUALLY incorrect anatomically. The bicep does contract slightly when the arm hinges up toward the shoulder(which this current driver setup does intiate), however one of the major functions of the biceps is to pronate and supinate the forearm (as in turning a doorknob). This current driver setup has ZERO bicep contraction when supinating/pronating the forearm. I’m not as great with expressions as you guys are, but I have implemented a change in the driver with a target bone to make it more realistic:

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We use ‘average value’ instead of scripted expression and target DEF-forearm.(x).001 bone

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then we add a ‘generator’ modifier with a coefficient of 1 (sorry don’t know if these pics are in order, Bitbucket won’t let me see these when I post them)

Not only can the output(effect) be minimized or maximized by changing the shapekey minimium and maximum values, but the it works great when setting up the triceps too (just change the target bone to the DEF-forearm bone and change ‘Type’ to x rotation and change the coefficient in the modifiers tab of the Driver Editor to -1. Although I don’t think this is necessary for triceps because the way it is currently setup with the scripted expresssion works fine. Anyway I know this isn’t a big deal, which is why this is just a proposal, and it isn’t important to most people, but I just thought I would contribute a little something if Thomas or anyone else is slightly interested. I don’t know if this can even be implemented into the addon the way I set it up--I understand writing a scripted expression is easier/more efficient, although again, for the biceps the visual output isn’t truly realistic. I have uploaded a few short clips showing before and after the driver is setup as well:

Current Driver hinge up/down:

https://mega.nz/file/eyxzXaCR#pqfCCJ51Ro3GuLZ31rsqUtO9ronRA8MBbvXiXkK_e7s

Current Driver supinate/pronate:

https://mega.nz/file/a7p2FSBb#p_BCe2FQ1sT-jbZSObN73UT5FM2SmoJIpf8LMU4rBWk

Improved Diver hinge up/down:

https://mega.nz/file/y2Bhxb5a#vU0KFUdSu_bW2sJKcQii4v1BohUwcNg83BQCHsbx2HQ

Improved Driver supinate/pronate:

https://mega.nz/file/LqJzwIoB#CwivuzidjXOecN9hnFJUFhqppgz9CHBRafhVaGOKNZs

Anyway, it’s up to you guys--I know I’ll be using these drivers in my setups moving forward.

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[Alessandro Padovani]

My opinion. The purpose of the addon is to import the figure as intended in daz studio. Changing the drivers “as we like it better“ is not a good idea, also because jcms depend on it. There’s a proposal in #1442 to get better drivers but it requires some work.

[Jasper29]

You’re right Alessandro. I just wanted to see if anyone would be interested in a more realistic setup for the flexions. In animating (unless by design) it’s good to have realistic feedback as much as possible, and thought it would be good if Diffeo automated something like this a little more. Anyway I also forgot to mention that 1: I’ve only set this up with Rigify not MHX, so things would be different between the 2 obviously, and 2: I forgot to mention that the current expression setup with Diffeo is still good/valid and my propsoal would combine the current driver with the newer one I mentioned--it would be a new input variable, but again I’m not great with writing expressions as it is so I would leave that up to Thomas (if he even entertains this idea of course) :)

[Alessandro Padovani]

there's already jcms for that in the daz figures, eventually with custom morphs packs