Lattice gas models use particles moving and interacting on a graph. Developed to simulate complex flows, they can be used to generate random structures on a physical basis. By addition of chemical reactions between species to fluid motion, reaction-diffusion models can be generated. This is illustrated by simulations of random textures obtained from a creation-annihilation model and from a multi-species model. Finally, by means of the immiscible lattice gas coupled with an aggregation process, stratified media reproducing the deposition of droplets are generated.