It is a great map. But when I opened it, I did notice it uses a custom Marble bitmap in the background, which makes it incompatible with the atlas. Not an issue for this challenge, but if your intention was to provide it to the atlas, that background will need to be changed.

There are no finished tools that does this, so you would have to do some manual drawing. If you have/make a single stair symbol, you could use the Symbols Along command to place them along the wall at appropriate distance/angles, and it even allows for a constant modification in scale if you want to use the effect from this image, i.e. that the stairs gets smaller and smaller to provide an illusion of them going down..

Very nice. Love the use of color key. The disadvantage with color key is that you can't really view the map at all with effects off, but it is a great effect to do a lot of things quickly and easy to change later.

This is a seriously weird one. The entity is still there, but all the nodes have the same coordinate, basically reducing it to a single point.

I tried drawing a huge square in the map and fractalizing that, and while it didn't disappear, it did do some weird things with the coordinates. Maybe @jslayton or @Ralf has any idea here.

Those of you who are active blog readers may already have noticed since I did publish it a week ago, but part 4 of my XP development series is now out, and it focuses on interacting with some of the core functionality on the CC3+ side of things, namely being able to interact with macro variables and call CC3+ commands from an XP.

Sorry for taking so long for the 4th part. I love writing these, but they also take a lot of time to prepare.