A dynamic parallax occlusion mapping algorithm based on per-pixel sphere tracing is proposed

in which the height map of the texture is preprocessed to build a shortest distance map for the practical surface saved in the height map from any points within texture height space. Then

the sphere tracing is carried out to obtain the accurate parallax offset of the texture in a pixel shader of graphic processing unit(GPU)by using distance map. Meanwhile

the self occlusion effect of texture is added to form the soft shadow. Applying the programmable GPU pipeline

the algorithm adopts hardware acceleration techniques to satisfy the needs of real-time rendering. Comparing with the dynamic parallax occlusion mapping(DPOM)which uses linear sampling with fixed step in the height map

the efficiency of the proposed algorithm can be increased by 3.3 times

and the texture floating phenomenon that exists in DPOM when step is bigger will not appears.