[vtkusers] how to extract the inner polydatas and outter polydata from a polydata?

[6dgis at 163.com]

Hi, all
     If a polydata consists of two or more polydatas, which may be exterior boundary or interior boundary.
how to extract them from the polydata ? how to determine each extracted polydata whether exterior or interior?
Any suggestion will be appreciated.
	

　
 				

　　　　　　　　6dgis
　　　　　　　　6dgis at 163.com
　　　　　　　　　　2005-09-01