Simple_spacer::rod_force (int l, int r, Real dist)
{
Real d = range_ideal_len (l, r);
- Real c = range_stiffness (l, r, d > dist);
+ Real c = range_stiffness (l, r, dist > d);
Real block_stretch = dist - d;
+
+ if (isinf (c)) /* take care of the 0*infinity_f case */
+ return 0;
return c * block_stretch;
}
for (vsize i=0; i < springs_.size (); i++)
inv_hooke += springs_[i].inverse_stretch_strength ();
+ if (inv_hooke == 0.0) /* avoid division by zero. If springs are infinitely stiff */
+ return 0.0; /* anyway, then it makes no difference what the force is */
+
assert (cur_len <= line_len_);
return (line_len_ - cur_len) / inv_hooke + force_;
}
/* Use a convex compression penalty. */
Real f = force_;
- return f - (f < 0 ? f*f*f*f*4 : 0);
+ return f - (f < 0 ? f*f*f*f*2 : 0);
}
/****************************************************************/