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Issue with upper arm joint rotation


#1

Hello,
I need very quickly a lego robot rig - it do not have to be super precise so I’m thinking about using simply arm_2jnt_02 - but I’m facing issues with upper arm rotation. Is there any quick way to lock that joint to fully follow FK control? Have the same issues in both FK and IK.

Please check the video to see what I mean.
link

If there is or not a solution, please let me know

Cheers,
Krzysztof


#2

I notice that the other day too, but since we are creating organic characters and we are using 1 twist joint we can kinda get away with it.
It would be nice to know if this is normal or a bug

also, you should add a Category to this post, like BUG or maybe SUPPORT


#3

So I did custom setup for that just for now, as we’re rushing a bit. But would be great if we could do that just with mgear without any extra rigging / scripting :wink: Would be awesome to have that for legs too.

Here’s a video with the result: https://www.dropbox.com/s/hjsnez0dehsy5jy/arm_goal.mp4?dl=0


#4

@Krzym The behaviour in by design for organic characters. But yep, that is not good for robots :stuck_out_tongue:

We need more specialised components for mechanical limbs


#5

As I thought :wink: For organic characters works awesome :wink: Maybe It’s a good excuse to learn how to build components.


#6

Go for it! A nice and easy first step is to clone a component and just edit it.

Copy a component that is close to what you want to do. Put it somewhere in a separate directory of your choosing.

Point that directory in your Maya.env
MGEAR_SHIFTER_COMPONENT_PATH = /your/path/to/customModules

In the guide.py of the new custom component, you need to change the TYPE and the NAME to be something unique. These lines are usually near the top, after the module imports.

For example the most simple module change I did was this: I cloned the control_01 component, and made my own called hook_01. Then I edited the component to not make any control icons, and to name it _hook instead of _ctl. I use these as blank nodes that can still have space switches, but the animators don’t see them. They don’t get added to the control selection sets.

If your guide settings and number of guide objects match, then in Maya, you can just go into the attribute editor of a guide, and change the .comp_type attribute. And the next time you open the guide settings it will load the settings for your custom module. (If your stuff doesn’t match, you’ll likely cause errors when you build.)

For example for me, I would change .comp_type from control_01 to hook_01 and the guide will automatically become a hook_01 component.

image

That way, you can change existing guides to another type of custom component without having to re-rig or place the guides over again.

Finally, then you just dig through __init__.py and edit the things you want to change. I think you have to restart Maya when you make changes to component code though. Utilities -> Reload didn’t always seem to work for me. But I haven’t tested that since mGear 3.1.


#7

Thank you @chrislesage for that explanation! It does not sound as complicated as I thought :wink: Will try for sure!