Digital stone rubbing from 3D models.

Stone rubbing is a traditional method to record surface features of a stone on paper. It has a long history and is still used by Chinese archaeologists and artists up to now. However, stone rubbing can cause permanent damage to precious cultural heritage due to abrasion. We propose a new method to create digital stone rubbing from 3D digital models. We assume the surface of a stone is flat locally and fit a least-squares plane to each point's neighbors individually. To prevent the local plane from being fitted across sharp edges or corners of the model, we make use of the smoothed point normals in the selection of local surface region. The height of a point is defined as the signed distance between the point and its local approximation plane. The estimated height of each point is then mapped to its grey value by a nonlinear transformation function. Finally, we render the 3D model into a rubbing image using orthogonal projection. We demonstrate the effectiveness of the method on real experimental dataset in archaeology. [ABSTRACT FROM AUTHOR]