Convexification, also called convex rearrangement, is an operation defined for absolutely continuous functions on a compact interval of $\mathbbR$. The so-called convexified of such a function $f$ is the unique convex function defined on the same interval whose derivative distribution is the same as that of $f'$, and is obtained by rearranging the increments of $f$ in ascending order. When $f$ is irregular, the consensus is to investigate the asymptotic convexification of regularizations. By extension, we define here the convexified of a smooth multivariate function with compact convex support as the unique convex function having the same gradient distribution. In this article, we discuss the asymptotic convexification of regularizations of random fields, with focus on Gaussian fields on the compact $[0,1]^d$. Given an irregular random field $X$, we consider polygonal approximations interpolating $X$ in the vertices of a triangulation whose diameter goes to 0. We give general results concerning the eventual limit after renormalization, with stronger results of convergence for gaussian fields. Along with other examples, we use these to show the existence of a limit convexified of the $d$-dimensional Chentsov field for a wide class of triangulations, and give the limit gradient distribution. In the 2-dimensional case, we give a tractable expression and a graphical representation of the limit convexified for a natural triangulation.