protected void createShape() {
        cShape = new BoxShape(Converter.convert(halfExtents));
        cShape.setLocalScaling(Converter.convert(getScale()));
        cShape.setMargin(margin);
    }
creates a collision box from the given halfExtents
@param halfExtents the halfExtents of the CollisionBox
jme3-jbullet/src/main/java/com/jme3/bullet/collision/shapes/BoxCollisionShape.java