24. Using Mesh

We will use the icosphere mesh created in Blender.

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First we have to copy the file to the Models folder of our project.

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We will set a background color of yellow.

        // *** 1. Start (Set background color as yellow)
        viewPort.setBackgroundColor(ColorRGBA.Yellow);
        // *** 1. End

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We show the 3 axes. Note, they are at a fixed place in 3D space, and we will not move them. However, they will rotate along the icosphere since they are all attached to rootNode.

        // *** 2. Start (Show coordinates, red x, green y, blue z)
        attachCoordinateAxes(new Vector3f(0,1,0));
        // *** 2. End

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We then load the icosphere mesh to a Spatial object.

        // *** 3. Start (Load Icoshpere --> ico)
        Spatial ico = assetManager.loadModel("Models/Icosphere.mesh.xml");
        // *** 3. End

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The material, applied to the Spatial object, is an unshaded Pink.

        // *** 4. Start (Set ico to pink color)
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Pink);
        ico.setMaterial(mat);
        // *** 4. End

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We attach it to rootNode.

        // *** 5. Start (Show it)
        rootNode.attachChild(ico);
        // *** 5. End

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In the update, we rotate the icosphere in all 3 directions. Since the icosphere is almost spherical, we only note slight changes in the sphere. However, we can easily see the changes in the arrows.

        // *** 6. Start (Rotate at different rates in x,y,z)
        rootNode.rotate(100*FastMath.DEG_TO_RAD*tpf,
                200*FastMath.DEG_TO_RAD*tpf,
                300*FastMath.DEG_TO_RAD*tpf);
        // *** 6. End

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// JMonkey3.java
package mygame;

import com.jme3.app.SimpleApplication;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.FastMath;
import com.jme3.math.Vector3f;
import com.jme3.renderer.RenderManager;
import com.jme3.scene.Geometry;
import com.jme3.scene.Mesh;
import com.jme3.scene.Spatial;
import com.jme3.scene.debug.Arrow;

public class JMonkey3 extends SimpleApplication {
    float rot = 0f;
    public static void main(String[] args) {
        JMonkey3 app = new JMonkey3();
        app.start();
    }
    
    private Geometry putShape(Mesh shape, ColorRGBA color) {
        Geometry g = new Geometry("coordinate axis", shape);
        Material mat = new Material(assetManager,
                "Common/MatDefs/Misc/Unshaded.j3md");
        mat.getAdditionalRenderState().setWireframe(true);
        mat.setColor("Color", color);
        g.setMaterial(mat);
        rootNode.attachChild(g);
        return g;
    }
    
    private void attachCoordinateAxes(Vector3f pos){
        Arrow arrow = new Arrow(Vector3f.UNIT_X);
        arrow.setLineWidth(2);
        putShape(arrow, ColorRGBA.Red).setLocalTranslation(pos);
        arrow = new Arrow(Vector3f.UNIT_Y);
        arrow.setLineWidth(2);
        putShape(arrow, ColorRGBA.Green).setLocalTranslation(pos);
        arrow = new Arrow(Vector3f.UNIT_Z);
        arrow.setLineWidth(2);
        putShape(arrow, ColorRGBA.Blue).setLocalTranslation(pos);
    }

    @Override
    public void simpleInitApp() {
        // *** 1. Start (Set background color as yellow)
        viewPort.setBackgroundColor(ColorRGBA.Yellow);
        // *** 1. End
        // *** 2. Start (Show coordinates, red x, green y, blue z)
        attachCoordinateAxes(new Vector3f(0,1,0));
        // *** 2. End
        // *** 3. Start (Load Icoshpere --> ico)
        Spatial ico = assetManager.loadModel("Models/Icosphere.mesh.xml");
        // *** 3. End
        // *** 4. Start (Set ico to pink color)
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Pink);
        ico.setMaterial(mat);
        // *** 4. End
        // *** 5. Start (Show it)
        rootNode.attachChild(ico);
        // *** 5. End
    }

    @Override
    public void simpleUpdate(float tpf) {
        // *** 6. Start (Rotate at different rates in x,y,z)
        rootNode.rotate(100*FastMath.DEG_TO_RAD*tpf,
                200*FastMath.DEG_TO_RAD*tpf,
                300*FastMath.DEG_TO_RAD*tpf);
        // *** 6. End
    }

    @Override
    public void simpleRender(RenderManager rm) {
        //TODO: add render code
    }
}

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Output: