Introduction

NetVtk is VTK 9.7.1's C++ API in C#, generated from VTK's headers. Names don't change: vtkPolyDataMapper is vtkPolyDataMapper, in the namespace Vtk. VTK's reference, its examples and forum answers apply as they are, once you know how signatures map; VTK's own documentation comes along in IntelliSense.

VTK's parts

• Data objects hold geometry and fields: vtkPolyData (surfaces, lines, points), vtkUnstructuredGrid (cells of any type: a mesh), vtkImageData (a regular grid). A field is a vtkDataArray with a value or vector per point or per cell.
• Algorithms make and change data: sources, readers, filters, writers. Connected output to input, they form a pipeline, which runs when asked for output.
• Rendering: a mapper turns data into graphics, an actor places it with its look, a renderer holds actors, lights and a camera, a render window draws its renderers.
• Objects count references. VTK frees an object when its last reference goes; a C# proxy holds one, see Object lifetimes.

Classes by task

Task	Classes	Guide
Points, cells, fields	vtkPoints, vtkCellArray, vtkUnstructuredGrid, vtkPolyData, vtkDoubleArray, vtkPointData, vtkCellData	Data and arrays
Shapes to start from	vtkSphereSource, vtkConeSource, vtkCubeSource, vtkArrowSource	Pipelines
Files	vtkXMLUnstructuredGridReader, vtkXMLPolyDataWriter, vtkUnstructuredGridReader (legacy .vtk), vtkExodusIIReader, vtkCGNSReader	Results
Results	vtkDataSetSurfaceFilter, vtkCutter, vtkContourFilter, vtkWarpVector, vtkThreshold, vtkGlyph3D	Results
Colours	vtkLookupTable, vtkScalarBarActor	Results
Drawing	vtkPolyDataMapper, vtkActor, vtkRenderer, vtkRenderWindow, vtkCamera, vtkWindowToImageFilter	Rendering and hosting
Volumes	vtkVolume, vtkVolumeProperty, vtkSmartVolumeMapper, vtkPiecewiseFunction, vtkColorTransferFunction	Rendering and hosting
Mouse input	vtkGenericRenderWindowInteractor, vtkInteractorStyleTrackballCamera	Rendering and hosting
Events, messages	vtkCommand, VtkOutput	Observers and messages

Reading the examples

Every example is a region of a test in netvtk-documentation/samples, compiled against the NetVtk package and run. Those that need a window compile only; those that render off the screen need OpenGL. They use C# 12 (collection expressions, using declarations) and using for every VTK object; Object lifetimes says where that matters.