We present a novel real-time approach for fine-scale surface deformations resulting from collisions. Deformations are represented by a high-resolution displacement function. When two objects collide, these offsets are updated directly on the GPU based on a dynamically generated binary voxelization of the overlap region. Consequently, we can handle collisions with arbitrary animated geometry. Our approach runs entirely on the GPU, avoiding costly CPU-GPU memory transfer and exploiting the GPU's computational power. Surfaces are rendered with the hardware tessellation unit, allowing for adaptively-rendered, high-frequency surface detail. Ultimately, our algorithm enables fine-scale surface deformations from geometry impact with very little computational overhead, running well below a millisecond even in complex scenes. As our results demonstrate, our approach is ideally suited to many real-time applications such as video games and authoring tools.