Using a Modified MIP-pyramid to Improve Parallax Mapping Performance

Abstract

The use of textures to simulate the irregularities on the surface provides for the establishment of ratio between screen coordinates and texture coordinates. For realistic playback irregularities there have been used different methods of texturing a relief. At the same time, the highest level of realism provides parallax mapping.

Parallax mapping is used to procedurally create three-dimensional generation of a textured surface using height maps instead of generating the building geometry. Parallax mapping is accomplished by offset of the texture coordinates so that the surface look fuller. The basic idea of the method is to determine the color of the pixel with texture coordinates at the point where the species vector intersects the surface. To offset the texture coordinates do the ray tracing to the height map. It requires a high computational cost. Existing methods to improve performance, often, lead to artifacts and do not provide an acceptable level of realism. Therefore, the aim of this research is to improve performance parallax mapping without loss of accuracy in determining the texture coordinates. Improving the performance of parallax mapping can be achieved through the use of additional special MIP-pyramid for storing the height map. In this pyramid instead of the average values of the four texels record the maximum value of the height at four points. The trace of the vector species should be performed alternately on all the MIP -the pyramid, starting from the highest and ending with the level that corresponds to the required resolution. Tracing the MIP -levels higher than the base allows excluding from the computational process inspection of large areas of texture.

The proposed method trace of the vector species with the use of a modified MIP-pyramid elevation map gives the possibility to significantly improve the performance of parallax mapping in many cases.