Help w/External Library Support on Linux

Building Urho3D has been pretty easy. No problems there. But I’m embarrassed to admit how long I’ve been working to get the cmake system to work properly with Urho3D as an external library, on Linux.

What I’ve done:
Cloned the repo
created Urho3D/build
configured cmake via cmake-gui to use build.
Made Urho3D into build as a static library.

At this point all the demos in build/bin work without issue. Cool beans! Next I create an external project directory. I reference [http]:// I specifically note this part of the page.

So I, “export URHO3D_HOME=/home/blah/project/Urho3D/build”. Side note, setting this or changing its value doesn’t seem to have any impact.
I create my CMakeLists.txt per the instructions.
No mention of a build directory is made on the page, but I go ahead and create one. I’ve also tried without. No change.
So, via cmake-gui, the source directory is set as the root of my project and the build directory is set as the build directory.
Tell it to configure. Get errors:

Interestingly enough, neither of those files exist inside the Urho3D tree. So no idea why it says it needs to locate files which simply don’t exist.

So, moving on, I set CMAKE_BUILD_TYPE to “Debug”. Now I’m specifically left with Urho3D_DIR. I’ve tried just about every combination I can imagine and nothing seems to make it happy. Regardless of the assigned value it’s always reset back to ‘Urho3D_DIR-NOTFOUND’. Which I guess it makes sense as the comments imply it should find of the files which has never existed.

Now then, I eventually did get things to work, but that was with actually installing things into /usr/local, via, “make install”, however, that’s not what I desire.

So, please feel free to kick me in the seat and tell me what I’m doing wrong. And in case it’s not clear, heeeeellllpppp! :frowning:


Ok, so you have the Urho3D source folder, and a build folder. And set the URHO3D_HOME environment variable.
so far so good.

This is what I do.

I have a project folder, example “/urho_project”.
Inside this folder I have a “/bin” folder and a “/src” folder.
And from the docs a "CMakeLists.txt"
as well, I have this script, that I call "/"
So I have so far:


Use the script passing in the path to the Urho3D source directory.

sh ./ /Urho3D

Pardon my bash, but it works:


#i need to create a bin folder if it does not exists /Urho3D_Source
#needs 1 arguents, the urho source folder

  if [ ! -e $3 ];then
    #link does not exist, we can make it
    ln -s $2 $3
    echo "          -"$1" directory LINKED"
    echo "          -"$1" link ALREADY EXISTS"

#first make sure that the given folder is good

if [ $# -eq 0 ];then
  echo "***********************************"
  echo "no arguments given, please provide:"
  echo "     -urho source path"
  echo "***********************************"
  if [ -d $URHOPATH ];then
  #if [[ ( -d $URHOPATH ) && ( -d $URHOBUILD ) ]];then

    echo "***********************************"
    echo "linking folders from urho source"

    # Absolute path this script is in, thus /home/user/bin
    SCRIPT=$(readlink -f "$0")
    SCRIPTPATH=$(dirname "$SCRIPT")

    #link the data and core data folder
    echo "     -link CMake, CoreData and Data folders"
    make_alias "CMake" $URHOPATH"/CMake" $SCRIPTPATH"/CMake"
    make_alias "CoreData" $URHOPATH"/bin/CoreData" $SCRIPTPATH"/bin/CoreData"
    make_alias "Data" $URHOPATH"/bin/Data" $SCRIPTPATH"/bin/Data"

    echo "***********************************"
    echo "create launch editor script"

    EDIT=$URHOPATH"/bin/Urho3DPlayer /Scripts/ -pp "$SCRIPTPATH"/bin -p \"CoreData;Data;Resources\" -w -s"
    if [ -f "$EFILE" ];then
      printf "$EDIT" > $EFILE
      echo " edited"
      touch $EFILE
      printf "$EDIT" > $EFILE
      echo " created"

    echo "***********************************"

    echo "***********************************"
    echo "invalid path or paths given:"
    echo "     -source:" $URHOPATH
    echo "***********************************"

What this script does it a few things.
It makes some necessary symbolic links.


Side note: The bash script also creates another bash script called “” I do this cause I usually modify it to pass in variables specific to my project as far as renderpaths that I want to editor to use, etc.

For completion, here is my CMakeLists.txt with a modification that searches sub folders in my “/src” directory:

# Set project name
project (your_urho_project_name)
# Set minimum version
cmake_minimum_required (VERSION 2.8.6)
if (COMMAND cmake_policy)
    cmake_policy (SET CMP0003 NEW)
        # INTERFACE_LINK_LIBRARIES defines the link interface
        cmake_policy (SET CMP0022 NEW)
    endif ()
        # Disallow use of the LOCATION target property - therefore we set to OLD as we still need it
        cmake_policy (SET CMP0026 OLD)
        # MACOSX_RPATH is enabled by default
        cmake_policy (SET CMP0042 NEW)
    endif ()
endif ()
# Set CMake modules search path
# Include Urho3D Cmake common module
include (Urho3D-CMake-common)
# Find Urho3D library
find_package (Urho3D REQUIRED)
include_directories (${URHO3D_INCLUDE_DIRS})
# Define target name
set (TARGET_NAME urho_project_executable_name)

# Define source files
#define_source_files (GLOB_CPP_PATTERNS src/*.cpp src/*.cc GLOB_H_PATTERNS src/*.h)

define_source_files (GLOB_CPP_PATTERNS src/*.c* GLOB_H_PATTERNS src/*.h* RECURSE GROUP )

# Setup target with resource copying
setup_main_executable ()

special attentions to the lines:

project (your_urho_project_name)
set (TARGET_NAME urho_project_executable_name)

Add your code to src, and that should do it. It does it for me anyway.

Thank you so much!

While I didn’t mention it, I was already linking CoreData and Data. I wasn’t, however, linking CMake at the root level. That instantly made everything happy.

I double checked the reference documentation (link above) and the phrasing implies this is optional. Linking or copying the CMake directory is clearly mandatory and not something you may want to consider. In retrospect I should have given it a go since it is specifically mentioned as optional. Perhaps the documentation will be updated to indicate it is in fact mandatory, not optional?

Sweet! Thanks so much!

There is an even simpler way, especially since you are using Linux as Ruby/Rake is already preinstalled. Execute this in the Urho3D project root (Urho3D repo clone dir).

rake scaffolding dir=/path/to/your/own/project/root

I had to install ruby and rake to test. It too works fine.