Function ApplyTransformToCamera

IO/Import/vtkGLTFImporter.cxx:457–483

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//------------------------------------------------------------------------------
void ApplyTransformToCamera(vtkSmartPointer<vtkCamera> cam, vtkSmartPointer<vtkMatrix4x4> transform)
{
  if (!cam || !transform)
  {
    return;
  }

  // At identity, camera position is origin, +y up, -z view direction
  double position[3] = { 0.0, 0.0, 0.0 };
  double viewUp[3] = { 0.0, 1.0, 0.0 };
  double focus[3] = { 0.0, 0.0, -1.0 };

  vtkNew<vtkTransform> t;
  t->SetMatrix(transform);

  t->TransformPoint(position, position);
  t->TransformVector(viewUp, viewUp);
  t->TransformVector(focus, focus);

  focus[0] += position[0];
  focus[1] += position[1];
  focus[2] += position[2];

  cam->SetPosition(position);
  cam->SetFocalPoint(focus);
  cam->SetViewUp(viewUp);
}
}

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