<div style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial"><div style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial"><div>Hello Everyone,<br>          How can I solve the error "Linking CXX executable FirstReconstruction<br>CMakeFiles/FirstReconstruction.dir/FirstReconstruction.cxx.o: In function `rtk::FDKWeightProjectionFilter<itk::Image<float, 3u>, itk::Image<float, 3u> >::BeforeThreadedGenerateData()':<br>FirstReconstruction.cxx:(.text._ZN3rtk25FDKWeightProjectionFilterIN3itk5ImageIfLj3EEES3_E26BeforeThreadedGenerateDataEv[rtk::FDKWeightProjectionFilter<itk::Image<float, 3u>, itk::Image<float, 3u> >::BeforeThreadedGenerateData()]+0x49): undefined reference to `rtk::ThreeDCircularProjectionGeometry::GetAngularGaps()' "?<br><br>Thank you very much!<br><br><br><br></div></div></div>