Error in "make" step (Raspberry Pi)

Hi everyone.

I’m trying to install Urho3D on RPi 3. (GPU = 768 MB)

I installed all the essential dependencies. All the steps went fine.
Until this error which occurred during the final make step:

[ 56%] Building CXX object Source/Urho3D/CMakeFiles/Urho3D.dir/Graphics/Skybox.cpp.o [ 57%] Building CXX object Source/Urho3D/CMakeFiles/Urho3D.dir/Graphics/Graphics.cpp.o In file included from /root/Urho3D/Source/Urho3D/Graphics/../Graphics/GraphicsImpl.h:29:0, from /root/Urho3D/Source/Urho3D/Graphics/Graphics.cpp:34: /root/Urho3D/Source/Urho3D/Graphics/../Graphics/OpenGL/OGLGraphicsImpl.h:36:23: fatal error: GLES2/gl2.h: No such file or directory #include <GLES2/gl2.h> ^ compilation terminated. Source/Urho3D/CMakeFiles/Urho3D.dir/build.make:1916: recipe for target 'Source/Urho3D/CMakeFiles/Urho3D.dir/Graphics/Graphics.cpp.o' failed make[2]: *** [Source/Urho3D/CMakeFiles/Urho3D.dir/Graphics/Graphics.cpp.o] Error 1 CMakeFiles/Makefile2:1198: recipe for target 'Source/Urho3D/CMakeFiles/Urho3D.dir/all' failed make[1]: *** [Source/Urho3D/CMakeFiles/Urho3D.dir/all] Error 2 Makefile:137: recipe for target 'all' failed make: *** [all] Error 2

Any suggestions?
What should I do !?

Although it is not related, do not use “root” account for anything else than administering your system!

Thanks @weitjong for your point.

One question:
Do I have to run “cmake_rpi.sh” instead of “cmake .” ?
(I followed the general linux tutorial.)