Search

Due to the bottlenecks such as low efficiency in the process of the virtual recovery of the Terra-Cotta Warriors broken fragments, this paper proposed a novel curvature-based point cloud automatic registration method. Firstly, it estimated curvature of each point by using MLS surface, then extracted the feature points based on the maximum local change of curvature. Secondly, it obtained the initial matching points by computing the Hausdorff distance of curvature, and acquired the accurate matching points by the PSO algorithm based on the maximum, minimum curvature similarity function. Finally, estimated the coordinate transform by the quaternion to achieve coarse registration, and improved the registration accuracy by the ICP algorithm. The experiments show the effectiveness and stability of this algorithm. [ABSTRACT FROM AUTHOR]

To achieve realtime collision detection of soft tissue in virtual surgery, this paper proposed an efficient detection algorithm based on delay updating strategy. The main contribution of this work was to use the technology of mixed bounding volumes to represent different objects in virtual surgery according to their feature of topology structure, meanwhile to reduce the cost of updating computation by delay strategy. First, this algorithm represented objects in surgery environment as different bounding volume hierarchies. Then it implemented the intersection test to eliminate disjoint parts fast. After that, it used more accurate triangle collision test to determine the contact status in overlapping parts. Finally it implemented updating computation on basis of delay strategy while soft tissue deformed. Experimental results show that this algorithm attains considerable speedup in most cases with respect to the existing algorithms. [ABSTRACT FROM AUTHOR]