Method UpdateViewProps

Rendering/Core/vtkLightActor.cxx:195–294

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
void vtkLightActor::UpdateViewProps()
{
  if (this->Light == nullptr)
  {
    vtkDebugMacro(<< "no light.");
    return;
  }
  double angle = this->Light->GetConeAngle();

  if (this->Light->GetPositional() && angle < 90.0)
  {
    if (this->ConeSource == nullptr)
    {
      this->ConeSource = vtkConeSource::New();
    }

    this->ConeSource->SetResolution(24);
    double* pos = this->Light->GetPosition();
    double* f = this->Light->GetFocalPoint();

    double direction[3];
    int i = 0;
    while (i < 3)
    {
      direction[i] = pos[i] - f[i];
      ++i;
    }
    double height = 1.0;
    double center[3]; //=pos

    double n = vtkMath::Norm(direction);

    // cone center is the middle of its axis, not the center of the base...
    i = 0;
    while (i < 3)
    {
      center[i] = pos[i] - 0.5 * height / n * direction[i];
      ++i;
    }
    this->ConeSource->SetCenter(center);
    this->ConeSource->SetDirection(direction);
    this->ConeSource->SetHeight(height);
    this->ConeSource->SetAngle(angle);

    if (this->ConeMapper == nullptr)
    {
      this->ConeMapper = vtkPolyDataMapper::New();
      this->ConeMapper->SetInputConnection(this->ConeSource->GetOutputPort());
      this->ConeMapper->SetScalarVisibility(0);
    }

    if (this->ConeActor == nullptr)
    {
      this->ConeActor = vtkActor::New();
      this->ConeActor->SetMapper(this->ConeMapper);
    }

    this->ConeActor->SetVisibility(this->Light->GetSwitch());