= Starting a JME3 application from the command-line
:revnumber: 2.0
:revdate: 2020/07/15
:keywords: documentation, install


Although we recommend the jMonkeyEngine xref:sdk:sdk.adoc[SDK] for developing JME3 games, you can use any IDE (integrated development environment) such as xref:jme3/setting_up_netbeans_and_jme3.adoc[NetBeans] or xref:jme3/setting_up_jme3_in_eclipse.adoc[Eclipse], and even work freely from the command-line. Here is a generic IDE-independent "`getting started`" tutorial.


== Installing the JME3 Framework

There are many ways to install the JME framework from the command-line, but for this tutorial we will narrow it down to two, the easy way and the hard way.

== Installing with Git (easy way)

You can build JME3 from the sources. (Recommended for JME3 developers.) This example expects link:https://help.github.com/articles/set-up-git/[Git] to be installed on your system.

[source]
----
mkdir jme3
cd jme3

// if you have a rsa key configured
git clone git@github.com:jMonkeyEngine/jmonkeyengine.git
// or
// if you don't, but you'll be asked for credential after the next command
git clone https://github.com/jMonkeyEngine/jmonkeyengine.git
//can take a while

// build the engine and install it in your local maven repo.
./gradlew install

----

TIP: What is an link:https://help.github.com/articles/adding-a-new-ssh-key-to-your-github-account/[RSA key]?

The install command will install the built jars into your local maven repositories org.jmonkeyengine folder, which on Linux is ~/.m2, and on Windows might be in AppData, or in your home directory.

To use the engine in a game project, you can use link:https://hub.jmonkeyengine.org/t/bootmonkey-bootstrap-your-jme-project/37141[BootMonkey] or clone a template project from GitHub.

To use the template, first create a folder for your project:

[source]
----
cd ..
mkdir HelloJME3
cd HelloJME3
----

Next, clone one of these templates:

*  link:https://github.com/Simsilica/Examples/tree/master/simple-jme[Simsilica/Examples]
*  link:https://github.com/Nehon/base-jme[Nehon/base-jme]

After cloning, open the `build.gradle` file and uncomment the `mavenLocal()` repository, change the version variable, and uncomment any dependencies you will need:

[source]
----
repositories {
    //This is where jme3 dependencies are stored.
    jcenter()

    //Uncomment this if you install local dependencies.
    mavenLocal()

    //Uncomment this if you use external dependencies
    //mavenCentral()

    //Uncomment this if you use jme3-niftygui
    //maven{url 'http://nifty-gui.sourceforge.net/nifty-maven-repo'}

}

ext.jmeVersion = "[3.2,)"

...

dependencies {

    compile "org.jmonkeyengine:jme3-core:$jmeVersion"
    compile "org.jmonkeyengine:jme3-desktop:$jmeVersion"
    compile "org.jmonkeyengine:jme3-lwjgl:$jmeVersion"

    //Those are jme3 additional library uncomment the ones you need
    //compile "org.jmonkeyengine:jme3-android-native:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-android:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-bullet-native-android:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-blender:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-bullet-native:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-bullet:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-effects:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-jogg:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-jogl:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-lwjgl3:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-networking:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-plugins:$jmeVersion"
    //compile "org.jmonkeyengine:jme3-terrain:$jmeVersion"

    //You need to uncomment nifty repository in the repositories section if you use this dependency
    //compile "org.jmonkeyengine:jme3-niftygui:$jmeVersion"

    runtime project(':assets')
}
...

----

For a detailed description of the separate jar files see xref:jme3/jme3_source_structure#structure_of_jmonkeyengine3_jars,this list].

That's it, you're done. After the clone, you will have a project that contains a source package with a default blue cube JME3 app and a subproject that has the proper asset directory structure for your assets.

Build and run your project and you should see a blue cube.


== Manual Download (hard way)


This example shows how to set up and run a simple application (HelloJME3) that depends on the jMonkeyEngine3 libraries.

The directory structure will look as follows:

[source]
----

jme3/
jme3/lib
jme3/src
...
HelloJME3/
HelloJME3/lib
HelloJME3/assets
HelloJME3/src
...
----

To install the development version of jme3, download the latest  link:https://github.com/jMonkeyEngine/jmonkeyengine/releases[stable release], unzip the folder into a directory named `jme3`. The filenames here are just an example, but they will always be something like `jME3.x-stable`.

[source]
----

mkdir jme3
cd jme3
unzip jME3.2-stable.zip
cd ..
----



== Sample Project Directory Structure

First we set up the directory and source package structure for your game project. Note that the game project directory `HelloJME3` is on the same level as your `jme3` folder. In this example, we create a Java package that we call `mygame` in the source directory.

[source]
----

mkdir HelloJME3
mkdir HelloJME3/src
mkdir HelloJME3/src/mygame

----


== Libraries

Next you copy the necessary JAR libraries from the download to your project. You only have to do this set of steps once every time you download a new JME3 build. For a detailed description of the separate jar files see xref:jme3/jme3_source_structure#structure_of_jmonkeyengine3_jars,this list].

[source]
----

mkdir HelloJME3/build
mkdir HelloJME3/lib
cp jme3/lib/*.* HelloJME3/lib

----


=== Sample Code

To test your setup, create the file `HelloJME3/src/mygame/HelloJME3.java` with any text editor, paste the following sample code, and save.

[source,java]
----

package mygame;

import com.jme3.app.SimpleApplication;
import com.jme3.material.Material;
import com.jme3.math.Vector3f;
import com.jme3.scene.Geometry;
import com.jme3.scene.shape.Box;
import com.jme3.math.ColorRGBA;

public class HelloJME3 extends SimpleApplication {

    public static void main(String[] args){
        HelloJME3 app = new HelloJME3();
        app.start();
    }

    @Override
    public void simpleInitApp() {
        Box b = new Box(Vector3f.ZERO, 1, 1, 1);
        Geometry geom = new Geometry("Box", b);
        Material mat = new Material(assetManager,
          "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Blue);
        geom.setMaterial(mat);
        rootNode.attachChild(geom);
    }
}
----


== Build and Run

We build the sample application into the build directory…

[source]
----

cd HelloJME3
javac -d build -cp "lib/eventbus.jar:lib/j-ogg-all.jar:lib/jme3-lwjgl.jar:lib/jme3-bullet.jar:lib/jinput.jar:lib/lwjgl.jar:lib/stack-alloc.jar:lib/vecmath.jar:lib/xpp3.jar:lib/jme3-blender.jar:lib/jme3-core.jar:lib/jme3-desktop.jar:lib/jme3-jogg.jar:lib/jme3-plugins.jar:lib/jme3-terrain.jar:lib/jme3-testdata.jar:lib/jme3-niftygui.jar:lib/nifty-default-controls.jar:lib/nifty-examples.jar:lib/nifty-style-black.jar:lib/nifty.jar:." src/mygame/HelloJME3.java

----

… and run it.

[source]
----

cd build
java -cp "../lib/eventbus.jar:../lib/j-ogg-all.jar:../lib/jme3-lwjgl.jar:../lib/jme3-bullet.jar:../lib/jinput.jar:../lib/lwjgl.jar:../lib/stack-alloc.jar:../lib/vecmath.jar:../lib/xpp3.jar:../lib/jme3-blender.jar:../lib/jme3-core.jar:../lib/jme3-desktop.jar:../lib/jme3-jogg.jar:../lib/jme3-plugins.jar:../lib/jme3-terrain.jar:../lib/jme3-testdata.jar:../lib/jme3-niftygui.jar:../lib/nifty-default-controls.jar:../lib/nifty-examples.jar:../lib/nifty-style-black.jar:../lib/nifty.jar:." mygame/HelloJME3
----

NOTE: If you use Windows, the classpath separator is kbd:[\ ]  instead of kbd:[/].

If a settings dialog pops up, confirm the default settings. You should now see a simple window with a 3-D cube. Use the mouse and the WASD keys to move. It works!


== Recommended Asset Directory Structure

For xref:tutorials:concepts/multi-media_asset_pipeline.adoc[multi-media files, models, and other assets], we recommend creating the following project structure:

[source]
----

cd HelloJME3
mkdir assets
mkdir assets/Interface
mkdir assets/Materials
mkdir assets/MatDefs
mkdir assets/Models
mkdir assets/Scenes
mkdir assets/Shaders
mkdir assets/Sounds
mkdir assets/Textures

----

This directory structure will allow xref:core:app/simpleapplication.adoc[SimpleApplication]'s default xref:core:/asset/asset_manager.adoc[AssetManager] to load media files from your `assets` directory, like in this example:

[source]
----

import com.jme3.scene.Spatial;
...
  Spatial elephant = assetManager.loadModel("Models/Elephant/Elephant.meshxml");
  rootNode.attachChild(elephant);
...

----

You will learn more about the asset manager and how to customize it later. For now feel free to structure your assets (images, textures, models) into further sub-directories, like in this example the `assets/models/Elephant` directory that contains the `elephant.mesh.xml` model and its materials.


== Next Steps

Now follow the xref:tutorials:beginner/beginner.adoc[tutorials] and write your first jMonkeyEngine game.
