Activiz（C＃）VTK与Python VTK渲染质量

Question

I have created a small tool in Python that shows a couple of STLs and creates a number of screenshots of them. Recently, I have converted this tool to C# using the Activiz VTK wrapper (both VTK implementations are version 5.8.0). The quality of the screenshots created in the C# implementation is similar to that of the Python screenshots, except where STLs overlap with eachother.

This is a Python VTK screenshot

And this is the corresponding Activiz VTK screenshot

As you can see, the red objects show through the beige one in Activiz VTK, the orange (and red) objects also show through the blue object on the left.

This is the Activiz render setup:

vtkOpenGLRenderer renderer = new vtkOpenGLRenderer();            
renderer.SetBackground(1, 1, 1);
vtkWin32OpenGLRenderWindow window = new vtkWin32OpenGLRenderWindow();
window.SetSize(1000, 1000);
window.AddRenderer(renderer);

STLs are added like this

vtkPolyDataMappermapper = vtkPolyDataMapper.New();
mapper.SetInput(_polydata);
vtkActor actor = vtkActor.New();
actor.SetMapper(mapper);
actor.GetProperty().SetColor((double)color.R / 255, (double)color.G / 255, (double)color.B / 255);
actor.GetProperty().SetOpacity(alpha);
actor.GetProperty().SetInterpolationToPhong();
renderer.AddActor(actor);

This is the original Python render setup

renderer = vtkOpenGLRenderer()
renderer.SetBackground(1,1,1)
window = vtkWin32OpenGLRenderWindow()
window.SetSize(1000,1000)
window.AddRenderer(renderer)

And STLs are added like this in Python

mapper = vtkPolyDataMapper()
mapper.SetInputData(polydata)
actor = vtkActor()
actor.SetMapper(mapper)
actor.GetProperty().SetColor(color)
actor.GetProperty().SetOpacity(alpha)
actor.GetProperty().SetInterpolationToPhong()
renderer.AddActor(actor)

Has anyone had a similar experience, or does anyone know what causes this difference in quality?

Kind regards

Answer 1

Maybe the cameras clipping planes (see "Perspective Projection") are set to different values. If the clipping range is too large such rendering errors can occur. Try to set it small enough so that all your objects are displayed. Haven't tried it but something like this:

renderer.GetActiveCamera().SetClippingRange(0.1, 100);

where the two arguments are the distances of the near and far clipping plane from the camera.