private void Frustum()
{
// Create a frustum.
// in this example we need the renderer first to retrieve the active camera
// in order to get camera's frustum planes
vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
vtkRenderer renderer = renderWindow.GetRenderers().GetFirstRenderer();
vtkCamera camera = renderer.GetActiveCamera();
double[] aspect = renderer.GetAspect();
double aspectRatio = aspect[0] / aspect[1];
// allocate memory for 24 unmanaged doubles
int size = Marshal.SizeOf(typeof(double)) * 24;
IntPtr ptr = Marshal.AllocHGlobal(size);
camera.GetFrustumPlanes(aspectRatio, ptr);
// in case we would need this values directly we could copy
// the unmanaged double array to a managed array like so:
// double[] planesArray = new double[24];
// Marshal.Copy(ptr, planesArray, 0, 24);
// but fortunately we can forward the IntPtr directly to the function
// SetFrustumPlanes()
vtkPlanes planes = vtkPlanes.New();
planes.SetFrustumPlanes(ptr);
// free unmanaged memory
Marshal.FreeHGlobal(ptr);
vtkFrustumSource frustumSource = vtkFrustumSource.New();
frustumSource.SetPlanes(planes);
frustumSource.Update();
vtkPolyData frustum = frustumSource.GetOutput();
// Visualize
vtkPolyDataMapper mapper = vtkPolyDataMapper.New();
mapper.SetInput(frustum);
vtkActor actor = vtkActor.New();
actor.SetMapper(mapper);
renderer.SetBackground(.2, .1, .3); // Background color dark purple
renderer.AddActor(actor);
renderer.ResetCamera();
}
private void Planes()
{
// in this example we need the renderer first to retrieve the active camera
// in order to get camera's frustum planes and renderer's aspectratio
vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
vtkRenderer renderer = vtkRenderer.New();
renderer = renderWindow.GetRenderers().GetFirstRenderer();
vtkCamera camera = renderer.GetActiveCamera();
double[] aspect = renderer.GetAspect();
double aspectRatio = aspect[0] / aspect[1];
vtkPlanes planes = vtkPlanes.New();
// one way
{
// allocate memory for 24 unmanaged doubles
int size = Marshal.SizeOf(typeof(double)) * 24;
IntPtr ptr = Marshal.AllocHGlobal(size);
camera.GetFrustumPlanes(aspectRatio, ptr);
// in case we would need this values diectly we could copy
// the unmanaged double array to a managed array like so:
// double[] planesArray = new double[24];
// Marshal.Copy(ptr, planesArray, 0, 24);
// but fortunately we can forward the IntPtr directly to the function
// SetFrustumPlanes()
planes.SetFrustumPlanes(ptr);
// free unmanaged memory
Marshal.FreeHGlobal(ptr);
}
// another way
{
vtkSphereSource sphereSource = vtkSphereSource.New();
sphereSource.Update();
double[] bounds = new double[6];
bounds = sphereSource.GetOutput().GetBounds();
planes.SetBounds(bounds[0], bounds[1], bounds[2], bounds[3], bounds[4], bounds[5]);
}
// nothing to visualize
}
