3D sphere OpenGL

Question

I would like to create a sphere, actually a globe. But I can’t find any useful information on how to handle vertices and indexes in a sphere, how to configure them. Can any of you lead me on the right path, maybe give me a sample code or a link to a tutorial?

Answer 1

The octahredon subsection works very well.

Answer 2

The simplest thing is to use glu functions. I work mainly in C, but in Java it is probably something like:

import net.java.games.jogl.GL; import net.java.games.jogl.GLU; import net.java.games.jogl.GLUquadric; ... GLUquadric quad = glu.gluNewQuadric(); glu.gluSphere(quad, 2, 10, 15); glu.gluDeleteQuadric(quad); 

This will create a sphere of radius 2 with 10 longitude divisions and 15 latitudinal divisions. It will also handle the creation of texture coordinates and regular normals.

If you really want to understand how to make subdivisions and create a spherical approximation yourself, you can see this code .

Answer 3

 import java.awt.Dimension; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import javax.media.opengl.GL; import javax.media.opengl.GL2; import javax.media.opengl.GLAutoDrawable; import javax.media.opengl.GLCapabilities; import javax.media.opengl.GLEventListener; import javax.media.opengl.awt.GLJPanel; import javax.swing.JFrame; public class Sphere extends GLJPanel implements GLEventListener,KeyListener { /** * */ private static final long serialVersionUID = -7419599978736850207L; private float rotateX, rotateY, rotateZ; public static void main(String[] args) { JFrame window = new JFrame("Cube"); GLCapabilities caps = new GLCapabilities(null); Sphere panel = new Sphere(caps); window.setContentPane(panel); window.pack(); window.setLocation(50, 50); window.setResizable(false); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.setVisible(true); panel.requestFocusInWindow(); } public Sphere(GLCapabilities capabilities) { // TODO Auto-generated constructor stub super(capabilities); setPreferredSize(new Dimension(500, 500)); addGLEventListener(this); addKeyListener(this); rotateX = 15; rotateY = 15; rotateZ = 0; } void drawSphere(double r, int lats, int longs,GL2 gl) { int i, j; for(i = 0; i <= lats; i++) { double lat0 = Math.PI * (-0.5 + (double) (i - 1) / lats); double z0 = Math.sin(lat0); double zr0 = Math.cos(lat0); double lat1 = Math.PI * (-0.5 + (double) i / lats); double z1 = Math.sin(lat1); double zr1 = Math.cos(lat1); gl.glBegin(gl.GL_QUAD_STRIP); for(j = 0; j <= longs; j++) { double lng = 2 * Math.PI * (double) (j - 1) / longs; double x = Math.cos(lng); double y = Math.sin(lng); gl.glNormal3d(x * zr0, y * zr0, z0); gl.glVertex3d(x * zr0, y * zr0, z0); gl.glNormal3d(x * zr1, y * zr1, z1); gl.glVertex3d(x * zr1, y * zr1, z1); } gl.glEnd(); } } void computeLocation(GL2 gl) { double x = 2 * Math.cos(0); // my x-, y-, and z-coordinates double y = 2 * Math.sin(0); double z = 20; double d = Math.sqrt(x * x + y * y + z * z); // distance to origin gl.glMatrixMode(gl.GL_PROJECTION); // Set projection parameters. gl.glLoadIdentity(); gl.glFrustum(-d * 0.5, d * 0.5, -d * 0.5, d * 0.5, d - 1.1, d + 1.1); } public void display(GLAutoDrawable drawable) { GL2 gl = drawable.getGL().getGL2(); gl.glClearColor(0, 0, 0, 0); gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT); gl.glMatrixMode(GL2.GL_PROJECTION); gl.glLoadIdentity(); gl.glMatrixMode(GL2.GL_MODELVIEW); gl.glLoadIdentity(); gl.glRotatef(rotateZ, 0, 0, 1); gl.glRotatef(rotateY, 0, 1, 0); gl.glRotatef(rotateX, 1, 0, 0); gl.glColor3d(1.0, 0.0, 0.0); drawSphere(1, 10, 10, gl); } public void init(GLAutoDrawable drawable) { // called when the panel is created GL2 gl = drawable.getGL().getGL2(); computeLocation(gl); gl.glEnable(GL.GL_DEPTH_TEST); } @Override public void dispose(GLAutoDrawable drawable) { } @Override public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) { } @Override public void keyPressed(java.awt.event.KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_LEFT) rotateY -= 15; else if (key == KeyEvent.VK_RIGHT) rotateY += 15; else if (key == KeyEvent.VK_DOWN) rotateX += 15; else if (key == KeyEvent.VK_UP) rotateX -= 15; else if (key == KeyEvent.VK_PAGE_UP) rotateZ += 15; else if (key == KeyEvent.VK_PAGE_DOWN) rotateZ -= 15; else if (key == KeyEvent.VK_HOME) rotateX = rotateY = rotateZ = 0; repaint(); } @Override public void keyReleased(java.awt.event.KeyEvent e) { // TODO Auto-generated method stub } @Override public void keyTyped(java.awt.event.KeyEvent e) { // TODO Auto-generated method stub } }