Geometry of pinch and punch tools

[Unsub Press]

Hi, guys

A quick question about the geometry of the pinch and punch tools in the liquify persona of photo.

I'm doing diagrams of spacetime metrics, and the pinch and punch tools seem the perfect fit for manipulating a grid to show negative and positive energy densities, (think gravity well and gravity peak). I have something that's not awful but, no matter how I manipulate the geometry of the tool, I can't get it to match my expectations. Here's an example, showing a gravity well on the right and an area of negative energy density on the left.

In particular, I expect more curve with the shrink (i.e., the centre shouldn't remain squares, but should also curve, with the degree of curvature increasing massively (pun intended) as it gets nearer the centre. I suspect this is to do with the fact that the application is radial rather than linear. 

I've tried multiple concentric applications with varying cursor sizes to try to get there but, of course, each previous application affects the result.

I have plans for a lot more diagrams of this nature in the future for various physics applications. Is there any way some sort of gradient tool could be applied, so that the upper and lower bounds of curvature could be user-defined? That was I can take maximum curvature from the centre and define the radius by length of gradient.

I'm guessing this wouldn't be the most requested feature ever, but it would make my diagrams much better and easier to construct.

Edit: I accept that this may just be CFIT on my part, and that there's an easier way to do what I'm trying. If there is, I'd appreciate any advice.

[PaulEC]

I haven't tried it myself, but have you tried using the "Pinch/Punch" live filter instead?

[GarryP]

Ah, I just got in too late.

Here's a screnshot anyway.

[Unsub Press]

Oooh, thank you both. That's much better.