This was one of the most difficult things I've worked with in Minecraft. Outcomes of experiments were so inconsistent that it's taken me over a week to put this mess of a video together.
Some things that happened in tests that were not shown in this video include signs becoming invisible upon return from the blue world, and the player losing body parts upon return. In one world, my player lost his right arm, and in another world, his right leg. The cause of all this is when the minecart is pushed by the piston. The minecart's x coordinate becomes NaN. When the minecart is broken, the chicken "gets out" of the minecart at the point in space where it was broken. Since the minecart didn't have an x coordinate, the game doesn't know what value to assign to the chicken. This results in NaN being used a placeholder for the value, which then in turn breaks several more calculations and game mechanics.
The Ideas are based on this video by Test137e29:
(Sorry If This doesn't belong in this thread, but this seems to be the only place on the forum where people can recognize and utilize a good creation :/ )
bravo my good man. how did you discover this??? by sheer luck or other means?
I experienced a similar bug prior to powered rails.
By creating rings of rails and filling them with hundreds of minecarts (obviously the rings of touching minecarts would cause them all to boost one another), the same forcefield effect was produced only at the Y coordinate of the carts. By jumping into that Y plane, it would hurl your pathetic meaty body dozens of blocks, usually resulting in death. Occasionally I also found minecarts thrown over 40 blocks away, sometimes through walls.
I wasn't able to go into much detail with my testing, however. 500 buggy minecarts at high speeds tends to make ancient computers stop working.
I never really had a use for it except to launch minecarts at cows, curious to see if the noclip works on SMP
I ran into a NaN value issue while testing out some TNT canon designs.
2 separate stacks @ 10 x 10 x 1 of TNT
lit using the staggered blocks with r.s torches alternating along the inside & outside.
The traditional way of powering a piston wall...
I didn't realize that r.s torches provide a small amount of lag between each level.
When the whole thing blew, the entire structure glitched out of existence... sort of.
I could see the blocks, & they would stop me from passing through them. I could even walk on them.
However.. I could NOT "pick" them, smash them, or even attach new blocks on to them.
I had to load up in MCedit & delete the whole thing in there. Even then, all the blocks where showing up as entities!?
Not quite as crazy as this though... mad scientist tweaking! Nice find!
I had discovered a similar thing. A few hundred or so minecarts in a ring with every other rail a powered rail would cause half of the minecarts to disappear or glitch off of the rails. Any mob that got within five blocks was sucked in and loaded into a minecart. I don't know if this affects anything, but each cart was dropped from above, not just placed on the tracks. On topic: That's some scary stuff, dude.
While the method you mention to remove the rift may work on some occasions, it doesn't for all. Because the rift is caused by the mob with the NaN X coordinates, deleting it removes rift. I assume your method works because the mob is able to despawn under those conditions. If this doesn't work, you can remove the mob manually in MCEdit or other minecraft world editing programs, so any worlds you may have accidentally glitched could still be saved.
This... Is so cool. I just love the way you go through it. It's like quantum science or something. It makes you a little tingely with a sense of discovery. It's like exploring the woods when you were little. I like this, a lot.
I tried making your forcefield and, finding I couldn't succeed in making it, decided to destroy the minecrarts and try again. However, when I did, the minecart sound kept playing, even when I left the world, so I had to exit out of minecraft. Really weird. Anyways, this is a really cool find!
Following the directions exactly still sort of works. You can still create an area where it is impossible to place solid blocks, but no nocliping through stuff. There may be a really extreme lag spike a second after you try to push the cart, but my computer survived and returned to normal speed after a minute. Saving and reloading released the chicken from the cart but the effect persisted.
"Pushing" the minecart back in the other direction with another piston turns the field off again. It is probably not practical for anything, but it is a toggleable way to keep players from placing solid blocks in a small flat area.