We propose a method for adding small-scale details to surfaces of 3D geometries in the context of interactive deformation computation of elastic objects. This is relevant in real-time applications, for instance, in surgical simulation or interactive animation. The key idea is the procedural generation of surface details via a weighted sum of periodic functions, applied as an on-surface displacement field. We first calculate local deformation strains of a low-resolution 3D input mesh, which are then employed to estimate amplitudes, orientations, and positions of high-resolution details. The shapes and spatial frequencies of the periodic details are obtained from mechanical parameters, assuming the physical model of a film-substrate aggregate. Finally, our approach creates the highly-detailed output mesh fully on the GPU. The performance is independent of the spatial frequency of the inserted details as well as, within certain limits, of the resolution of the output mesh. We can reproduce numerous commonly observed, characteristic surface deformation patterns, such as wrinkles or buckles, allowing for the representation of a wide variety of simulated materials and interaction processes. We highlight the performance of our method with several examples.