How do I check if instances of the same object are within a certain radius of eachother?

I've done something like this where TILE is the object I'm checking:

SYSTEM

Picky by comparison

distance(TILE.x, TILE.y, TILE.x, TILE.y)

TILE

(action I want to happen)

I'm pretty sure it's not recognizing that I want to test the distance between 2 separate instances. How do I do this properly?

Without using families, which are available only in the paid version, you will need to know the IID of each instance you want to compare.

With the IID you can reference specific instances by adding (IID) before the fullstop.

e.g. sprite(0).X and Sprite(1).X

To get the distance between object IID=0 and object IID=1 you would use:

distance(Sprite(0).X,Sprite(0).Y,Sprite(1).X,Sprite(1).Y)

You need to use a Global Variable to hold the initial starting X,Y position. Then you can let each instance hold their own value for Distance calculated off the Global.

This video will give you more details:

youtu.be/KN4gp6cC3bA