In my game I have block based building (it will be slightly easier for you to answer this question if you have ever played the game minecraft). One feature I wanted to add in is lets say you build a tall building and you cut out the bottom then the building falls over as a single object (the whole top that you just cut off from the base). I have been trying many things such as fixed joints and empty game objects but nothing seems to be working that would not involve lots of complicated scripts and calculations. Any ideas? Thanks!
so to save processing you want to stay away from constant checks like update to do this god its going to be tricky
um so one possible way is whenever a player places a block the block is special in that it has some variable in it that identifies that it was placed by the player
next when a player places a block, as soon as its placed it looks around once if it senses other blocks directly connected to it that were also set by the player than it creates an empty gameobject and sets itself as a child of that object if it senses that there already is an object like that it will just add itself to it
after doing this check you can put a script in there that removes this component
next the parent gameobject would be created with a rigidbody
now theoretically if you dig out the bottom, the default physics engine would take over after that you can make scripts to determine what would happen if stuff like this occurs without having to use Update
SendMessage is going to be your BF
but this is roughly the only way you can achieve this effect mainly because you are having to deal with processing loads and defining player generated objects from natural objects that still should behave similarily to the natural objects
you can use complex scripts you just have to word them so they dont require complex processing