function update(value) {
                  check(value);
  
                  position += 0.01 * sign * speed;
                  rotation += 0.02;
                  color = value;
  
                  speed = speed * ( 1  - sign * accel); 
  
                  object.translation.y = position;
                  object.color = new SFColor(1,color,color);
                  object.rotation = new SFRotation(0.5,0.5,0,rotation);
                  }