i’ve noticed that code in PSolve_Links of btsoftbody.cpp:
k=((l.m_c1-len)/(l.m_c0*(l.m_c1+len)))*kst;
a.m_x-=del*(k*a.m_im);
b.m_x+=del*(k*b.m_im);
i know the code is used for adjusting the length for one link each step,but i can’t figure out why we caculate “k” like that,please HELP!