if you look at the material definitions you will see that every material defines a collision start, process and end callback. these are the functions that get called if a newton entity with that material collides with something (for more information about this you could look into the manual of the newton c-api). if you return(0); in these functions the collision gets ignored. i am not sure if this was already implemented in the old plugin but i am 99% sure that it was.
