Are animated B tiles possible?

I want to make a portal that is animated but doesn't cover a whole tile (because it would look really weird if it were square) Is there anyway to make a B tile animate, because it would be very annoying to have to make it on A1s with different corners so that the ground won't abruptly change right before it.

Also does anyone know of a way to make a bridge over a path that you can walk under or over, with out having players being capable of walking off the bridge onto the lower path and vice versa.

1. Animating Tiles

I'm not an expert on the matter, but I believe you can just make a character sheet for particular tile that you want to animate. Just make sure it is in the correct format and build it into a character sheet. If it is a single icon/character with only 3 frames just keep direction fix on and build 1 row. Remember to put a $ before the file name when including it in the project if it is a single character. Then put it on the map as an event with walking animation.

2. Bridge Passability

If it is for a bridge. You can use Neon Black's Terrain Tags script.

One of the functions is specifically for bridge passability like you describe in the request.

I have not used this particular script before. According to the thread there seems to be a few minor bugs but for bridges it seems fine.

~ Dinhbat

No, animated B tiles aren't possible, that's what events are for.  That's what dinhbat3 is describing in his answer.

Okay thanks, it's a shame there are no animated B tiles, that would make things a lot easier. I'll probably just use events so you automatically cross/go under bridges when you walk up to them.