I found method to add IK rigs by Attila in that topic: http://modthesims.info/t/504353
I try to understand it and I think I can find out his method. I try to imitate it and it's my method and the problem I'm encoutering:
You can download my file as well as Attila's file here: https://drive.google.com/file/d/0Bw...iew?usp=sharing
I notice that if I check Invert (in all three axis) in Copy Rotation, it will cause mesh deformation when add Inverse Kinesmatic to the calf. So, it's impossible to check Invert.
I extremely need your help. And Attila, if you're reading it, please show me where did I go wrong?