Joining delaunay and voronoi

I want to add Delaunay triangulation to one side of my Voronoi structure something similar to the 2nd picture
Is there a way to make the Delaunay more appropriate/ to better fit the surface? and also how to join them together so that they blend (meaning we cant see the Delaunay from the inside)? sorry if my questions are a bit silly but Im still learning the program…