Weird Blurring/Shadowing After Using VtkPolyDataClipper.


I am using the VtkPolyDataClipper to cut some Polydata into a few pieces, however, the Clipped Polydata coloring looks a little weird. The Clipped Polydata should be a smaller section of the original but should have the same coloring properties.

Any advice is appreciated.

Full Model:
Screenshot 2021-02-20 233429
Clipped Model:
Screenshot 2021-02-20 233441

It looks like the attributes (i.e. the colors) are being interpolated. Are the colors stored as point attributes, or are they cell attributes? Point attributes are interpolated when data is clipped.

If your polydata is made of a whole bunch of small cells, then vtkExtractPolyDataGeometry is a better filter to use. It has a PassPointsOn() method that can be used to pass the points directly from the input to the output, with no modification whatsoever. Only cells will be removed.

Hey David,

Thanks for your response!

So there are some properties being stored on the cell, which causes no interpolation when coloring using those properties, but the issue I was having was with properties on points. After some digging, I did figure out that the original unclipped polydata had certain duplicate points with two different property ids (on specific coincident points) which were being merged together (found this from my other post you replied to) and causing this interpolation to happen. My solution was to provide a custom locator to the clipper that overrides the InsertUniquePoint function, this seems to work but not sure if it’s the best solution. Thanks for pointing me in the right direction!