FOSS gamedev and creative worlds

I wanted to make a 2x2 trapdoor that opens when activated and closes when deactivated. So I have a total of 12 sticky pistons below the floor ( 4 up, and 8 sideways ). I use NOT gates so when the switch is off the pistons are extended. When the switch is turned on the sticky up pistons pull the floor down, then the 8 sticky pistons pull the pistons and the floor blocks to the side fully opening the trap door. The key is an ABBA circuit. This makes sure the pistons push and pull in the correct order. It makes the 4 up pistons pull first, then the side pistons, then it works the opposite when the switch is deactivated, the side pistons push the up pistons and floor blocks back into place then the up pistons push the floor blocks back in place.



This is a screen shot of the ABBA circuit as I was testing it. I actually learned how to do these in minecraft so I wondered if it was possible in Minetest and it is (it can malfunction if there is a lot of lag but most of the time it works great). You need 4 delayers, laid out as in the screen shot. The two parallel delayers that face opposite directions need to be set at full delay, and the other two need to be set at minimal delay. In the screen shot when the switch in the lower left is activated the nearest light lights up first, and the furthest light lights up second, when the switch is deactivated the furthest light goes off first, and the nearest light goes off second.

I made a video of the trapdoor in action. There is lag from the video recording in some parts.

http://www.youtube.com/watch?v=yEqClE9Jt6A

That's 2*2, not 4*4.

That is pretty impressive! Turned sideways, I could make it into the hidden door I've always wanted, but could never figure out how to build. Thanks for sharing!

0gb.us wrote:That's 2*2, not 4*4.

Your right, 2x2 ... 4 blocks total.

Impressive......=D