31. Binary j3o

The mesh file is a text file. The data has to be converted to binary before release, to run outside SDK.

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You should right-click on the mesh.xml file and select the first option to convert to j3o binary.

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This will create the mesh.j3o file inside the Textures, Pyramid folder. Move it to Models, Pyramid subfolder. This will get the project structure shown here.

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To use the new file, we will have to change the load String.

// Load model
        Spatial pyramid = assetManager.loadModel(
                "Models/pyramid/pyramid.mesh.j3o");

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30. UV Unwrap + Texture

Mesh surfaces are usually textured.

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Texture is a 2D image, and the 3D surface has to be UV mapped into 2D space.

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In Blender, we select all vertices in the Edit Mode. Then using Mesh header menu, we select UV Unwrap and Smart UV Project. The UV should now appear in the UV/Image Editor. We should create a new image file.

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Next from the UVs header menu, we have to select Export UV Layout, and save the image.

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Any image editing software can be used. We could even make the edits in UV/Image Editor in Blender. However, the software used most often is GIMP. The Bucket Fill tool quickly adds a pattern to the different slots for different surfaces. We have to make sure the patterns are tileable. If we need more control, we could also write a script to create a texture image.

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In the GIMP, the different slot corresponding to different surfaces, are filled in with a suitable pattern.

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After exporting the structure with a material and texture, we create a pyramid folder in Textures folder and put the files there, after renaming them.

// JMonkey30.java

package mygame;

import com.jme3.app.SimpleApplication;
import com.jme3.light.AmbientLight;
import com.jme3.math.ColorRGBA;
import com.jme3.math.FastMath;
import com.jme3.renderer.RenderManager;
import com.jme3.scene.Spatial;
import com.jme3.system.AppSettings;

public class JMonkey30 extends SimpleApplication {
    public static void main(String[] args) {
        // App Settings
        AppSettings settings = new AppSettings(true);
        settings.setTitle("Pyramid!");
        settings.setFrameRate(60);
        JMonkey30 app = new JMonkey30();
        app.setSettings(settings);
        app.setDisplayFps(false);
        app.setDisplayStatView(false);
        app.start();
    }

    @Override
    public void simpleInitApp() {
        flyCam.setEnabled(false); // disable camera inputs
        viewPort.setBackgroundColor(ColorRGBA.LightGray); // background
        // Load model
        Spatial pyramid = assetManager.loadModel(
                "Textures/pyramid/pyramid.mesh.xml");
        // Ambient light
        AmbientLight ambient = new AmbientLight();
        ambient.setColor(ColorRGBA.White);
        rootNode.addLight(ambient);
        
        // Initial Rotation
        pyramid.rotate(45*FastMath.DEG_TO_RAD, 0, 0);
        rootNode.attachChild(pyramid);
    }

    @Override
    public void simpleUpdate(float tpf) {
        // Rotation per frame
        rootNode.rotate(0,0.005f,.005f);
    }

    @Override
    public void simpleRender(RenderManager rm) {
    }
}

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Output:

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