Here is a tutorial on how to create a gradation per domain on hexagonal grid

modeling workflow is as follow:

1. create base surface with domains - Voronoi is used

2 create hexagon grid of points

3 group the points per domain - islayingOn + indexOf

4 create curve attractor from the domain's boundary

5 set the attractor curves to domain's points (the ones laying on) - "curve attractor" and "apply attractor"

6 normalize the value of the impacted center translation - "Stats" + "Threshold"

7 create hexagons centers on the hexagonal grid of points with radius set from the normalized value of attraction

let me know if you have another way! I think it could be a good exercise to skill-up.

​​​​​​​

3dxml result is stored within the zip file

going further a little, domains could be defined by list of sketches like below.