Combining displacement mapping methods on the GPU for real-time terrain visualization

Real-time terrain visualization plays an important role in multiple popular applications. In these applications, displacement mapping algorithms (both per-vertex and per-pixel methods) can be used to improve the accuracy and performance of terrain rendering. Per-vertex methods are usually implemented by means of hardware tessellation, and per-pixel techniques, such as parallax mapping, apply changes at the pixel level using the fragment shader. However, parallax mapping has not still been used in real-time terrain visualization applications due to different reasons. In this paper, we propose a comparison study of different combinations of per-vertex and per-pixel methods. The performance evaluation results reveal that any of the implemented schemes improve the performance of terrain rendering, with respect to the performance yielded by the exclusive use of hardware tessellation. These results validate the proposed schemes as efficient alternatives for real-time terrain visualization applications.