fatal error: Eigen/Dense: No such file or directory while building

[insomniaacoma]

error occurs when
[ 49%] Building CXX object openMVG/features/CMakeFiles/openMVG_features.dir/akaze/AKAZE.cpp.obj
from D:\jichuang\openMVG\src\openMVG\features\akaze\AKAZE.cpp:9:
D:/jichuang/openMVG/src/openMVG/image/image_container.hpp:12:10: fatal error: Eigen/Dense: No such file or directory
#include <Eigen/Dense>
^~~~~~~~~~~~~
compilation terminated.
make[2]: *** [openMVG/features/CMakeFiles/openMVG_features.dir/akaze/AKAZE.cpp.obj] error 1
make[1]: *** [openMVG/features/CMakeFiles/openMVG_features.dir/all] error 2
make: *** [all] error 2
Thx for any tips.

[qingzhengzhuma]

building in which way?

[insomniaacoma]

Make. After "cmake ..", I simply run make.

[pmoulon]

Can you clear your cmake cache and share here what is the output of CMake configure?

For some reason Eigen is not found or incomplete.

[insomniaacoma]

[cmake] ** OpenMVG version: 2.1.0
[cmake] ** Build Shared libs: OFF
[cmake] ** Build OpenMVG tests: OFF
[cmake] ** Build OpenMVG softwares: ON
[cmake] ** Build OpenMVG GUI softwares: ON
[cmake] ** Build OpenMVG documentation: ON
[cmake] ** Build OpenMVG samples applications: ON
[cmake] ** Build OpenMVG openGL examples: OFF
[cmake] ** Enable code coverage generation: OFF
[cmake] ** Enable OpenMP parallelization: ON
[cmake] ** Build OpenCV+OpenMVG samples programs: OFF
[cmake] ** Use OpenCV SIFT features: OFF
[cmake] ** Use LiGT for global translation estimation: ON
[cmake]
[cmake]
[cmake]
[cmake]
[cmake] -- CEREAL: (internal)
[cmake] -- EIGEN: (external)
[cmake] -- CERES: 1.13.0 (internal)
[cmake] -- FLANN: 1.8.4 (internal)
[cmake] -- LIBTIFF: (internal)
[cmake] -- LIBPNG: (internal)
[cmake] -- LIBJPEG (internal)
[cmake] -- CLP: 1.16.10 (internal)
[cmake] -- COINUTILS: 2.10.13 (internal)
[cmake] -- OSI: (internal)
[cmake] -- LEMON: 1.3 (internal)
[cmake] -- Configuring done (14.7s)
[cmake] -- Generating done (2.1s)
I'll clear my cmake cache later and update the result.

[qingzhengzhuma]

seems fine. where or how your eigen installed?

[insomniaacoma]

D:\eigen-3.4.0\eigen-3.4.0，I downloaded eigen from https://eigen.tuxfamily.org/index.php?title=Main_Page

[insomniaacoma]

I cleared my CMake cache and then performed “cmake ../src” and "make", but "fatal error: Eigen/Dense: No such file or directory" still poped.

[qingzhengzhuma]

This is weired, if you didn't tell cmake where your eigen installed or add eigen path to environment variable, cmake should use internal eigen but the log tells external eigen used. you can try to print the eigen path found by cmake.

[insomniaacoma]

i added EIGEN_ROOT to environment variable and i use gcc on windows

[insomniaacoma]

i deleted env EIGEN_ROOT to disable external eigen, and this error occured :
You are attempting to build without Eigen. Please use cmake variable
-DEIGEN_INCLUDE_DIR_HINTS:STRING="PATH" or EIGEN_INCLUDE_DIR_HINTS env.
variable to a valid Eigen path. Or install last Eigen version.
Call Stack (most recent call first):
third_party/ceres-solver/CMakeLists.txt:173 (find_package)

[insomniaacoma]

i rebuilt OpenMVG with MSVC and it worked though i still can't figure out the reason. Thx for your help