Learn JMONKEYENGINE with Real Code Examples

import com.jme3.app.SimpleApplication;
import com.jme3.font.BitmapText;

public class CounterApp extends SimpleApplication {
    private int count = 0;
    private BitmapText counterText;

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

    @Override
    public void simpleInitApp() {
        counterText = new BitmapText(guiFont, false);
        counterText.setSize(guiFont.getCharSet().getRenderedSize());
        counterText.setText("Count: " + count);
        counterText.setLocalTranslation(300, counterText.getLineHeight(), 0);
        guiNode.attachChild(counterText);
    }

    @Override
    public void simpleUpdate(float tpf) {
        count++;
        counterText.setText("Count: " + count);
    }
}

A minimal jMonkeyEngine application displaying a counter in a 3D scene and updating it each frame.

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

public class MovingBoxApp extends SimpleApplication {
    private Geometry box;

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

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

    @Override
    public void simpleUpdate(float tpf) {
        box.move(0, 0, 1 * tpf);
    }
}

A simple box moving forward in the 3D scene.

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

public class RotatingCubeApp extends SimpleApplication {
    private Geometry cube;

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

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

    @Override
    public void simpleUpdate(float tpf) {
        cube.rotate(0, 1 * tpf, 0);
    }
}

Rotates a cube around the Y axis every frame.

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

public class JumpingSphereApp extends SimpleApplication {
    private Geometry sphere;
    private float vy = 0;
    private float y = 1;
    private float gravity = -9.8f;

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

    @Override
    public void simpleInitApp() {
        Sphere s = new Sphere(16,16,1);
        sphere = new Geometry("Sphere", s);
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Green);
        sphere.setMaterial(mat);
        sphere.setLocalTranslation(0,y,0);
        rootNode.attachChild(sphere);
    }

    @Override
    public void simpleUpdate(float tpf) {
        vy += gravity * tpf;
        y += vy * tpf;
        if (y < 1) { y = 1; vy = 5; } // bounce
        sphere.setLocalTranslation(0, y, 0);
    }
}

A sphere jumps up and falls down simulating gravity.

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

public class CameraFollowApp extends SimpleApplication {
    private Geometry box;

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

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

    @Override
    public void simpleUpdate(float tpf) {
        box.move(1 * tpf, 0, 0);
        cam.setLocation(box.getLocalTranslation().add(0,5,10));
        cam.lookAt(box.getLocalTranslation(), Vector3f.UNIT_Y);
    }
}

Camera follows a moving object.

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

public class ColorBoxApp extends SimpleApplication {
    private Geometry box;
    private float time = 0;

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

    @Override
    public void simpleInitApp() {
        Box b = new Box(1,1,1);
        box = new Geometry("Box", b);
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        box.setMaterial(mat);
        rootNode.attachChild(box);
    }

    @Override
    public void simpleUpdate(float tpf) {
        time += tpf;
        box.getMaterial().setColor("Color", new ColorRGBA((float)Math.abs(Math.sin(time)), 0, 1-(float)Math.abs(Math.sin(time)), 1));
    }
}

Box changes color every frame.

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

public class SpinningTorusApp extends SimpleApplication {
    private Geometry torus;

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

    @Override
    public void simpleInitApp() {
        Torus t = new Torus(16,16,1,2);
        torus = new Geometry("Torus", t);
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Cyan);
        torus.setMaterial(mat);
        rootNode.attachChild(torus);
    }

    @Override
    public void simpleUpdate(float tpf) {
        torus.rotate(tpf, tpf, 0);
    }
}

A torus spinning along multiple axes.

import com.jme3.app.SimpleApplication;
import com.jme3.bullet.BulletAppState;
import com.jme3.bullet.control.RigidBodyControl;
import com.jme3.scene.Geometry;
import com.jme3.scene.shape.Box;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;

public class FallingBoxApp extends SimpleApplication {
    private BulletAppState bulletAppState;

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

    @Override
    public void simpleInitApp() {
        bulletAppState = new BulletAppState();
        stateManager.attach(bulletAppState);
        Box b = new Box(1,1,1);
        Geometry box = new Geometry("Box", b);
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Magenta);
        box.setMaterial(mat);
        box.addControl(new RigidBodyControl(1f));
        rootNode.attachChild(box);
        bulletAppState.getPhysicsSpace().add(box);
    }
}

Box falls under gravity using Bullet physics.

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

public class OrbitCameraApp extends SimpleApplication {
    private float angle = 0;

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

    @Override
    public void simpleInitApp() {
        Sphere s = new Sphere(16,16,1);
        Geometry sphere = new Geometry("Sphere", s);
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.White);
        sphere.setMaterial(mat);
        rootNode.attachChild(sphere);
    }

    @Override
    public void simpleUpdate(float tpf) {
        angle += tpf;
        cam.setLocation(new Vector3f(10 * (float)Math.cos(angle), 5, 10 * (float)Math.sin(angle)));
        cam.lookAt(Vector3f.ZERO, Vector3f.UNIT_Y);
    }
}

Camera orbits around a central object.