Sens de vt pour les segments est correct

scontact/scontact.c

@@ -420,7 +420,7 @@ static int contactParticleDiskSolve(Contact *c, ParticleProblem *p, double dt, d
     p->velocity[c->o1 * DIMENSION]*t[0]+
     p->velocity[c->o1 * DIMENSION+1]*t[1]+
     p->omega[c->o1]*p->particles[c->o1].r+
-    p->disks[c->o0].vt*((t[0]!=0) ? -(1-2*signbit(t[0])) : (1-2*signbit(t[0])) );
+    p->disks[c->o0].vt;
   const double mu = particleProblemGetMu(p,p->particleMaterial[c->o1],p->diskMaterial[c->o0]);
   double ct = 0;
   if(vt>(3./1.)*mu*dp){
@@ -461,12 +461,14 @@ static int contactParticleSegmentSolve(Contact *c, ParticleProblem *p, double dt
   double t[2];
   t[0] = -c->n[1];
   t[1] = c->n[0];
+  Segment seg = p->segments[c->o0];
+  double sign = (seg.p[0][0]-seg.p[1][0])*t[0] + (seg.p[0][1]-seg.p[1][1])*t[1];
   double vt = c->ct +
     c->ct*p->particles[c->o1].r*c->In1+
     p->velocity[c->o1*DIMENSION]*t[0]+
     p->velocity[c->o1*DIMENSION +1]*t[1]+
     p->omega[c->o1]*p->particles[c->o1].r+
-    p->segments[c->o0].vt*((t[0]!=0) ? -(1-2*signbit(t[0])) : (1-2*signbit(t[0])) );
+    seg.vt*( sign>0 ? 1 : -1 );
   const double mu = particleProblemGetMu(p,p->particleMaterial[c->o1],p->segmentMaterial[c->o0]);
   double ct = 0;
   if(vt>(3./1.)*mu*dp){