Method MyRotateCamera

Interaction/Style/vtkInteractorStyleUnicam.cxx:611–648

Rotate the camera by 'angle' degrees about the point and around the vector/axis .

// and around the vector/axis <ax, ay, az>.
//
void vtkInteractorStyleUnicam::MyRotateCamera(
  double cx, double cy, double cz, double ax, double ay, double az, double angle)
{
  angle *= 180.0 / vtkMath::Pi(); // vtk uses degrees, not radians

  double p[4], f[4], u[4];
  vtkCamera* camera = this->CurrentRenderer->GetActiveCamera();
  camera->GetPosition(p);
  camera->GetFocalPoint(f);
  camera->GetViewUp(u);
  p[3] = f[3] = 1.0; // (points)
  u[3] = 0.0;        // (a vector)

  vtkTransform* t = vtkTransform::New();
  t->PostMultiply();
  t->Identity();
  t->Translate(-cx, -cy, -cz);
  t->RotateWXYZ(angle, ax, ay, az);
  t->Translate(cx, cy, cz);

  double new_p[4], new_f[4];
  t->MultiplyPoint(p, new_p);
  t->MultiplyPoint(f, new_f);

  double new_u[4];
  t->Identity();
  t->RotateWXYZ(angle, ax, ay, az);
  t->MultiplyPoint(u, new_u);

  camera->SetPosition(new_p[0], new_p[1], new_p[2]);
  camera->SetFocalPoint(new_f[0], new_f[1], new_f[2]);
  camera->SetViewUp(new_u[0], new_u[1], new_u[2]);

  // IMPORTANT!  If you don't re-compute view plane normal, the camera
  // view gets all messed up.
  camera->ComputeViewPlaneNormal();
  t->Delete();
}

// Translate the camera by the offset <v[0], v[1], v[2]>.  Update
// the camera clipping range.