Texture sample instead of sphere mask

Hi, first time poster so please let me know if I’m doing something wrong. Usually I find what I’m looking for on the forums, but I can’t quite get the wording for this right, but here goes.

So I have a top down game going on where I use a sphere mask to cut away parts of materials where my character is standing. Simple enough, but it’s really ugly to just cleanly cut it away. Making the material translucent and scaling hardness creates a whole bunch of issues so I figured I’d use a Posterized image to simulate the effect. then the question arose: How do I move a texture sample’s center based on world location?

The idea seems so simple to me but I can’t seem to feed the location parameters into it without cruncing it into just R and G.
I’ve bounced this idea around for the past few months but never really found a solution to it.

and of course I forgot to post the images

alt text

Check WorldAlignedTexture node.
It changes the texture to work just like sphere mask, in world space.