Shoulderrig with CAT

[.B3N]

Hi there,

I use CAT since a half year and I´m happy with it but there are two damn things I can´t get fixed and I hope that somebody can help me with this. The first one ist the shoulderrig and my first question. Did anyone get a clean CAT shoulderrig running? My complete actual work stucks because I can´t find a way to fix it. I tried two different meshvariants, I played with the weight of the skinning between the upper arm and the clavicle, I tried it with a seperate shoulderbone. No way. Nothing works.

The second question is about a Root Bone. I searched different forums, this one too, and there was somebody who had the same question. I need a root-bone in animation to rotate my character with the right amount of weight. When he rotatas in the pelvis, it looks inkorrekt. I don´t mean the Layer Transform Gizmo (I tried to reposition it, no way), it must a bone, a bit top of the pelvis. I tried a extra bone as parent of the pelvis but it doesn´t work very well because then there are other problems when the whole rig moves. I´m really confused.

Is there anybody who could say me more about my two problems please?

Cheers and a great week - Ben


To show you what I mean I show you the pics:

[Daelus]

I'm not familiar with CAT specifically, but any purely bone based rigging solution will run into issues with deformations when pushed too far. This is because all the vertexes can do is rotate around joints (which will basically always reduce volume).

To compensate for this most rigs will use blend shapes driven by joint rotation, muscle systems, or some sort of extra bone who's position is driven by the original's rotation to compensate for the compression. I have no idea how you'd go about integrating that into CAT though.

Lastly, one of the reasons I'd think you're having problems with the shoulder when you bend it back like that is because people... well, can't really do that. He has a broken or dislocated shoulder in that pose. Also, keep in mind as you set weights that a lot of the movement happens above the shoulder. Your spine will also compensate for any more extreme poses. Anyway, good luck.

[.B3N]

Thank you for your answer, I post my question in different forums but this is the first answer I get

I don´t know whether the blend shape driven by joint rotation method works with the UDK. At the moment I test a method with one more bone in the shoulder and, well, it works better but I really don´t know why and it´s a pain to animate it. I think I will try to avoid this extreme angels