## General* Create [vtkMultiBlockDataSetAlgorithm](https://vtk.org/doc/nightly/html/classvtkMultiBlockDataSetAlgorithm.html) base classes for filters that return multiple inputs (e.g. the pending Euclidean cluster extraction filter).
## Create a pcl::Feature ClassA number of PCL filter classes derive from [pcl::Feature](http://docs.pointclouds.org/trunk/classpcl_1_1_feature.html) and thus share several parameters. A common class and base proxy should be introduced to share these parameters across several filters. The main difficulty is the lack of support for multiple inheritance and templated inheritance in VTK. As only a linear hierarchy is possible, the possible solutions are not ideal. This is yet another reason to reconsider an approach that generates filters automatically from simple configuration files.