static inline btScalar SignedUnitRand() { return(UnitRand()*2-1); }
static inline float RandInterval(float s, float e) { return s + (e - s) * UnitRand(); }
static inline btScalar SignedUnitRand() { return(UnitRand()*2-1); }
static inline float RandInterval(float s, float e) { return s + (e - s) * UnitRand(); }