Method ComputeMatrix

Rendering/VR/vtkVRPanelRepresentation.cxx:327–369

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//------------------------------------------------------------------------------
void vtkVRPanelRepresentation::ComputeMatrix(vtkRenderer* ren)
{
  // check whether or not need to rebuild the matrix
  // only rebuild on left eye otherwise we get two different
  // poses for two eyes
  vtkCamera* cam = ren->GetActiveCamera();
  if (this->CoordinateSystem != World && cam->GetLeftEye())
  {
    vtkVRRenderWindow* rw = static_cast<vtkVRRenderWindow*>(ren->GetVTKWindow());

    if (this->CoordinateSystem == HMD)
    {
      vtkTransform* vt = cam->GetViewTransformObject();
      vt->GetInverse(this->TextActor->GetUserMatrix());

      if (rw->GetPhysicalScale() != this->LastScale)
      {
        double ratio = rw->GetPhysicalScale() / this->LastScale;
        double* scale = this->TextActor->GetScale();
        this->TextActor->SetScale(scale[0] * ratio, scale[1] * ratio, scale[2] * ratio);
        double* pos = this->TextActor->GetPosition();
        this->TextActor->SetPosition(pos[0] * ratio, pos[1] * ratio, -0.5 * rw->GetPhysicalScale());
        this->LastScale = rw->GetPhysicalScale();
      }
      else
      {
        double* pos = this->TextActor->GetPosition();
        this->TextActor->SetPosition(pos[0], pos[1], -0.5 * rw->GetPhysicalScale());
      }
    }

    vtkEventDataDevice device = this->CoordinateSystem == LeftController
      ? vtkEventDataDevice::LeftController
      : vtkEventDataDevice::RightController;

    vtkNew<vtkMatrix4x4> deviceToWorldMatrix;
    if (rw->GetDeviceToWorldMatrixForDevice(device, deviceToWorldMatrix))
    {
      // transform the text to the devices location in world coordinates
      this->TextActor->GetUserMatrix()->DeepCopy(deviceToWorldMatrix);
    }
  }
}

//------------------------------------------------------------------------------
int vtkVRPanelRepresentation::RenderOpaqueGeometry(vtkViewport* v)