# Using part of VTK in my own project?
**URL:** https://discourse.vtk.org/t/using-part-of-vtk-in-my-own-project/3010
**Category:** Support
**Created:** [April 9, 2020, 9:53pm UTC](https://discourse.vtk.org/t/using-part-of-vtk-in-my-own-project/3010 "2020-04-09T21:53:36Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Ahmed\_Salih](https://discourse.vtk.org/u/Ahmed_Salih)
#### Post date: [April 9, 2020, 9:53pm UTC](https://discourse.vtk.org/t/using-part-of-vtk-in-my-own-project/3010/1 "2020-04-09T21:53:36Z")
Hello!
So this is my first time trying to achieve something like this. What I want to is basically to use some functionality provided in this example in my own project;
[https://lorensen.github.io/VTKExamples/site/Cxx/IO/WriteVTP/](https://lorensen.github.io/VTKExamples/site/Cxx/IO/WriteVTP/)
I have managed to build VTK and know that I can run the example without any errors, so every header is functional etc.
What I think I have to do is to use cmake in something like this:
> cmake\_minimum\_required(VERSION 3.3 FATAL\_ERROR)
>
> project(MyProject VERSION 1.0.0)
>
> add\_library(
>
> ```
> AllTheCode
>
> Bi4File.cpp
>
> Bi4File.h
>
> bi4read.c
>
> bi4read.h
>
> Block.cpp
>
> Block.h
>
> BlockHelper.h
>
> drawGeom.h
>
> Geometry.h
>
> horspool.c
>
> horspool.h
>
> Particle.cpp
>
> Particle.h
>
> Statistics.h
>
> SubBlock.cpp
>
> SubBlock.h
>
> Tuple.h
>
> Vector.h
>
> ```
>
> )
>
> #a.out is executable
>
> add\_executable(a.out main.cpp)
>
> set(LIBS AllTheCode)
>
> target\_link\_libraries(a.out PRIVATE ${LIBS})
So this code is all the code except the vtk example and I am very unsure of how to include it, since it needs its own CMakeLists.txt to even compile. I have not been succesful in doing this but I am doing something like:
> cmake\_minimum\_required(VERSION 3.3 FATAL\_ERROR)
>
> project(WriteVTP)
>
> SET(VTK\_DIR “/home/aras/vtk-build/” CACHE PATH “VTK directory override” FORCE)
>
> find\_package(VTK COMPONENTS
>
> CommonCore
>
> CommonDataModel
>
> IOXML)
>
> if (NOT VTK\_FOUND)
>
> message(“Skipping WriteVTP: ${VTK\_NOT\_FOUND\_MESSAGE}”)
>
> return ()
>
> endif()
>
> message (STATUS “VTK\_VERSION: ${VTK\_VERSION}”)
>
> if (VTK\_VERSION VERSION\_LESS “8.90.0”)
>
> # old system
>
> include(${VTK\_USE\_FILE})
>
> add\_executable(WriteVTP MACOSX\_BUNDLE WriteVTP.cxx )
>
> target\_link\_libraries(WriteVTP PRIVATE ${VTK\_LIBRARIES})
>
> else ()
>
> # include all components
>
> add\_executable(WriteVTP MACOSX\_BUNDLE WriteVTP.cxx )
>
> target\_link\_libraries(WriteVTP PRIVATE ${VTK\_LIBRARIES})
>
> # vtk\_module\_autoinit is needed
>
> vtk\_module\_autoinit(
>
> ```
> TARGETS WriteVTP
>
> MODULES ${VTK_LIBRARIES}
>
> )
>
> ```
>
> endif ()
And when ever I try to include it, it ends up not working. Could anyone help me to get this up and running?
To sum up again; I want to use this specific vtk functionality in my own code - unsure how to go about that and cannot make CMake accept it, so I can use the function in my own code. If I just add it as a “header file” it can’t find the vtk headers correctly.
Kind regards
---
### Author:  [@Ahmed\_Salih](https://discourse.vtk.org/u/Ahmed_Salih)
#### Post date: [April 10, 2020, 2:48pm UTC](https://discourse.vtk.org/t/using-part-of-vtk-in-my-own-project/3010/2 "2020-04-10T14:48:23Z")
Am I the first to want to do, what I am writing about or maybe I was not clear enough initially?
Basically what I have now is:
Which generates a working executable. But I am not able to link it to my main project. Any suggestions?
Kind regards
---
### Author:  [@danlipsa](https://discourse.vtk.org/u/danlipsa)
#### Post date: [April 10, 2020, 3:02pm UTC](https://discourse.vtk.org/t/using-part-of-vtk-in-my-own-project/3010/3 "2020-04-10T15:02:34Z")
Please, copy paste the commands you issued and the error you got, directly from the terminal.
---
### Author:  [@Ahmed\_Salih](https://discourse.vtk.org/u/Ahmed_Salih)
#### Post date: [April 10, 2020, 3:14pm UTC](https://discourse.vtk.org/t/using-part-of-vtk-in-my-own-project/3010/4 "2020-04-10T15:14:47Z")
Sure 🙂 So this is what I have right now:
For the VTK file generation
For the whole project:
And when I compile the error I get right now is:
I think I am pretty close… just having some small misunderstanding I guess.
Kind regards
---
### Author:  [@Ahmed\_Salih](https://discourse.vtk.org/u/Ahmed_Salih)
#### Post date: [April 10, 2020, 3:23pm UTC](https://discourse.vtk.org/t/using-part-of-vtk-in-my-own-project/3010/5 "2020-04-10T15:23:47Z")
Okay, so I actually got it to build succesfully now by changing in “VTK file generation”, at line 11, by including “SHARED” keyword as such:
And it seems to link properly to my main program now. But I am a bit unsure on how to call a function from a .so file in C++?
Basically the function looks like this:
But how would I use this “func” in my main file for example?
Kind regards