A geometry- and texture-based automatic discontinuity trace extraction method for rock mass point cloud

Abstract

This paper presents an automatic extraction method for discontinuity trace mapping from 3D point cloud of natural rocky slopes. Unlike the methods based only on geometrical information, the proposed method also takes textural information into account. By using the texture mapping method, a texture map and a normal map are generated from the point cloud, which contain textural and geometrical information respectively. Then, the rolling guidance filter and a multi-scale edge chain detector are applied to the image to extract discontinuity traces. Finally, edge chains in the image were projected back to the 3D coordinate system through the previously established texture map. The proposed method is applied to three case studies, each representing a different situation. The results show that the proposed discontinuity trace extraction method is automatic, robust, extensible and performs better than geometry-based methods for smooth rock surfaces along which the curvature changes are not apparent. The proposed method could be used as a supplement to traditional contact discontinuity trace mapping methods.