Useful tricks with portalgun checkpoints

[Fuubar]

I thought i would point some interesting "features" of PortalGun checkpoints.


Here is an image of a checkpoint on top of a stone block. As you can see, it inherits the stone texture from the block below it.


Now if I activate the left piston in the pic above, it will push the redpower lamp beneath the portal block. If it were a normal block the checkpoint would change texture (which is an awesome "feature"). However, checkpoints don't inherit textures from redpower blocks so the checkpoint becomes invisible.


The cool glitch is that checkpoints do inherit some of the metadata from the redpower lamp. Specifically, when the lamp is on, it inherits the light shell and it also emits light. The checkpoint doesn't stop emitting light when the lamp is turned off.


Personally, I think this glitch has great potential for cool lighting effects. As an example, Here is a futuristic version of the firebridge from slowpoke's stream:

The checkpoint "lamps" next to the track activate as the minecart passes, but are otherwise invisible.




The wiring for this bridge is also really simple. The setup is just a track ontop of a checkpoint (with the checkpoint feature disabled and redstone pulse set to entities) ontop of an iron block. On each side of the center checkpoints are two lamps with a checkpoint on top of each of them. Underneath a bit of wire that connects the block powered by the center checkpoint to the lamps.


Just for fun, here are three more simple systems that take advantage of the the checkpoint+piston texture switching.

An FTB logo that changes colors:





and some hidden lights:



Also, a light floor that brings back memories of the glass platform trick people used to mod before being able to toggle creative and survival: (it is just an array of lamps with checkpoints on them)

 

[Cieronph]

1 question, how on earth did you figure this out?

 

[DarkJDL]

Can you stick the blocks ontop of one another and still have that effect? (block 1 inherits from light, block 2 inherits from block 1, etc...?) if so, I have some ideas brewing up.

 

[Fuubar]

1 question, how on earth did you figure this out?

I wanted to see what textures and effects a checkpoint would inherit from blocks that change. I was using a lever to toggle the bottom block on and off. The lever happened to be on when I placed the RP2 lamp, so I didn't realize that it doesn't properly inherit from RP2 blocks until I turned the lever off.

I discovered the piston trick when testing if the checkpoint has any other interesting properties. It breaks itself if you remove the block under it, but i wanted to see if I could move the bottom block without breaking the checkpoint (to see if I could accomplish something like DarkJDL is thinking of). Turns out the checkpoint checks the to see if the block below it is valid after the bottom block has gone through a transition (being moved by pistons or frames) and breaks itself if it finds an incompatible block (like air). However, the checkpoint doesn't check while the block below it is in a transition; it only checks after the transition is done. If the block below the checkpoint is still valid after the transition, then it just updates its texture.

Can you stick the blocks ontop of one another and still have that effect? (block 1 inherits from light, block 2 inherits from block 1, etc...?) if so, I have some ideas brewing up.

I wish you could, but checkpoints cant be placed on-top of other checkpoints. I wanted to make a force-field wall where only the blocks near a player are visible (similar to the bridge I posted, but taller). I found the trick with pistons, but was unsuccessful in my original goal. The best I was able to do was a a layered approach (lamp-checkpoint-lamp-checkpoint) and I couldn't hide the circuitry very well.