Beginner issue with getting a Driver to refer to "self" so I can link it to many objects

Question

I'm trying to get an object to scale with its distance to another object, so I can then link the driver to the rest of the 639 objects in the collection.

I need it to somehow refer to itself, rather than explicitly selecting the object, so that when I link the driver, each of the linked objects will scale individually with their own proximity to the sphere. The intention is for each of the hexagonal objects to scale down when the sphere gets close.

In this thread, one answer says that if Use Self is checked, I can do the distance measurement in the expression itself if I use Single Property and use the sphere's matrix.world as the Object, but matrix.world isn't accepted when I try this.

In addition, is there a way I can get the driver to control XYZ scale so I don't need to use 3 drivers?

If I'm going about this in the wrong way I don't mind restarting the project.

Thanks in advance.

Attaching my blend file as requested. In this file, the driver is working correctly, but that's by specifying icosphere.083 as Object 2. I need it to work by somehow referring to "self" or "this object", so I can link the driver to other objects and have it work per object.

https://drive.google.com/file/d/15irt899Fqtbtfo_iWR2t4CbLpn6CDl5t/view?usp=sharing

Answer 1

I noticed in your file that you had had a go with Geometry Nodes.. so as a side-note, this would be a possible arrangement:

The Length of the 'Relative' (i.e. owner's Object-Space) Location of the Object Info target is the distance from the GN-modified object-origin to the target object-origin. You can use some function of that for object-level proximity effects:

Answer 2

you can use this script:

import bpy

# two sample functions
def calcDistance(object):
    
    location2 = bpy.context.scene.objects["AssaultSphere"].location
    print("loc2", location2)
    location1 = object.location
    print("loc1", location1)
    distance = (location2 - location1).length
    
    print(distance * 3)

    return distance

# Add functions defined in this script into the drivers namespace.
bpy.app.driver_namespace["calcDistance"] = calcDistance

driver settings:

result: