How to build it in ubuntu16.04?

[lsongseven]

Could you please specify how to build it in ubuntu16.04 or explain the steps? Googled a lot but still cannot build it.

[MattClarkson]

Did you try cmake?

[lsongseven]

Oh thanks, finally make it. I thought there were something related with pods according to readme, but just find that cmake is enough.

…

On Fri, Nov 23, 2018 at 3:43 PM Matt Clarkson ***@***.***> wrote: Did you try cmake? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AZZ83cIspl6Rt55Y328UrUtzi3Tdp4S5ks5ux6c0gaJpZM4YwIuU> .

[jackm]

Just to clarify, is this the correct way to build the package?

Starting at the repository root directory:

cd cmake
cmake ..

Do I need to run make as well? When I try to do that, I get the following error:

Scanning dependencies of target apriltags
[  6%] Building CXX object CMakeFiles/apriltags.dir/src/FloatImage.cc.o
[ 13%] Building CXX object CMakeFiles/apriltags.dir/src/Quad.cc.o
/home/user/apriltags/src/Quad.cc:1:23: fatal error: Eigen/Dense: No such file or directory
compilation terminated.
CMakeFiles/apriltags.dir/build.make:86: recipe for target 'CMakeFiles/apriltags.dir/src/Quad.cc.o' failed
make[2]: *** [CMakeFiles/apriltags.dir/src/Quad.cc.o] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/apriltags.dir/all' failed
make[1]: *** [CMakeFiles/apriltags.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2

I get the same error if I try to run make from the repo root directory as well.

[MattClarkson]

No. You should not build within the source folder. Given you have

/home/user/apriltags/src/

I suggest you delete it and reclone the src repository to make sure it is clean. Then,

mkdir /home/user/apriltags/build
cd /home/user/apriltags/build
ccmake ../src

set whichever options you need, but probably leave default. Then generate.
Then compile with

make

If you are unsure of CMake try stuff like: https://cliutils.gitlab.io/modern-cmake/chapters/intro/running.html

[jackm]

Still no good. I believe that cmake is not finding or was not given the eigen3 library include directory. On my system running Ubuntu 16.04.5 LTS, the eigen library is found at /usr/include/eigen3/.

A quick hack was to add the line set(Eigen_DIR "/usr/include/eigen3/") to the root CMakeLists.txt before the first configure_file() line. After this, I was able to compile everything using make without errors.

Could you please update the main README to include build steps?

[onlineth]

This should definitely be added, thank you @jackm