// btSeed2 is used for re-arranging the constraint rows. improves convergence/quality of friction
protected long btSeed2 = 0L;
public SequentialImpulseConstraintSolver() {
BulletGlobals.setContactDestroyedCallback(new ContactDestroyedCallback() {
public boolean contactDestroyed(Object userPersistentData) {
assert (userPersistentData != null);
ConstraintPersistentData cpd = (ConstraintPersistentData) userPersistentData;
//btAlignedFree(cpd);
totalCpd--;