I am not too clear on the collision bitmasks, (up to now I have used simple 1’s and 0’s) and am having trouble setting one collisionNode to multiple masks. (I have a 0 mask and a 1 mask, and want something to be both 0 and 1). Looking at the docs, it seems that I would want to make one take the middle bits, one take the lower bits, but am unsure how to do this. Any help appreciated.