Is it necessary to have gl/glew installed to run vtk?

I believe VTK’s OpenGL support uses GLEW. While RenderingCore doesn’t care, any extant rendering backend will need it.

Cc: @sankhesh

If you’re using VTK to process data (run algorithms) and I/O, you don’t need OpenGL.
If you’re doing any kind of rendering, then yes, you need OpenGL support.

I have openGl installed but I guess I don’t have the glew libraries. Is it a problem?

Thank you

VTK ships with a vendored glew library, so you can build that instead.