38. Cylinder

A Cylinder is one of the built-in mesh shapes.

---

We can find number of vertices and their coordinates.

        // *** 2. Start (Vertices)
        VertexBuffer position = cylinder.
                getBuffer(Type.Position);
        Vector3f[] array = BufferUtils.
                getVector3Array((FloatBuffer)position.
                getData());
        System.out.println("cylinder has " +
                array.length +
                " vertices. Coordinates are: ");
        int i = 0;
        for (Vector3f v : array) {
            System.out.printf("%d\t%s\n",i++,v);
        }
        // *** 2. End

---

This materials tests if the mesh structure is correctly loaded.

        // *** 3. Start (Material)
        Material mat = new Material(assetManager,
                "Common/MatDefs/Misc/ShowNormals.j3md");
        geoCylinder.setMaterial(mat);
        // *** 3. End

---

We have constant rotations to see the mesh from different angles.

        // *** 4. Start (Rotation per frame)
        rootNode.rotate(.5f*tpf, .1f*tpf, .2f*tpf);
        // *** 4. End

---

// JMonkey38.java

package mygame;

import com.jme3.app.SimpleApplication;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.Vector3f;
import com.jme3.renderer.RenderManager;
import com.jme3.scene.Geometry;
import com.jme3.scene.VertexBuffer;
import com.jme3.scene.VertexBuffer.Type;
import com.jme3.scene.shape.Cylinder;
import com.jme3.system.AppSettings;
import com.jme3.util.BufferUtils;
import java.nio.FloatBuffer;

public class JMonkey38 extends SimpleApplication {
    public static void main(String[] args) {
        AppSettings settings = new AppSettings(true);
        settings.setFrameRate(57);
        settings.setTitle("Cylinder !");
        JMonkey38 app = new JMonkey38();
        app.setSettings(settings);
        app.start();
    }

    @Override
    public void simpleInitApp() {
        viewPort.setBackgroundColor(
                new ColorRGBA(1f,.9f,.8f,1));
        setDisplayFps(false);
        setDisplayStatView(false);
        flyCam.setEnabled(false);
        // *** 1. Start (cylinder mesh)
        Cylinder cylinder = new Cylinder(8,8,1.5f,2.5f,true);
        Geometry geoCylinder = new Geometry("cylinder", cylinder);
        
        // *** 2. Start (Vertices)
        VertexBuffer position = cylinder.
                getBuffer(Type.Position);
        Vector3f[] array = BufferUtils.
                getVector3Array((FloatBuffer)position.
                getData());
        System.out.println("cylinder has " +
                array.length +
                " vertices. Coordinates are: ");
        int i = 0;
        for (Vector3f v : array) {
            System.out.printf("%d\t%s\n",i++,v);
        }
        // *** 2. End
        // *** 3. Start (Material)
        Material mat = new Material(assetManager,
                "Common/MatDefs/Misc/ShowNormals.j3md");
        geoCylinder.setMaterial(mat);
        // *** 3. End

        rootNode.attachChild(geoCylinder);
    }

    @Override
    public void simpleUpdate(float tpf) {
        // *** 4. Start (Rotation per frame)
        rootNode.rotate(.5f*tpf, .1f*tpf, .2f*tpf);
        // *** 4. End
    }

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

---

Output: