Can't get LWJGL lighting to work
- by Zarkonnen
I'm trying to enable lighting in lwjgl according to the method described by NeHe and this post. However, no matter what I try, all faces of my shapes always receive the same amount of light, or, in the case of a spinning shape, the amount of lighting seems to oscillate. All faces are lit up by the same amount, which changes as the pyramid rotates. Concrete example (apologies for the length):
Note how all panels are always the same brightness, but the brightness varies with the pyramid's rotation.
This is using lwjgl 2.8.3 on Mac OS X.
package com;
import com.zarkonnen.lwjgltest.Main;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
import org.lwjgl.util.glu.*;
import org.lwjgl.input.Keyboard;
import java.nio.FloatBuffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
/**
*
* @author penguin
*/
public class main {
public static void main(String[] args) {
try {
Display.setDisplayMode(new DisplayMode(800, 600));
Display.setTitle("3D Pyramid");
Display.create();
} catch (Exception e) {
}
initGL();
float rtri = 0.0f;
Texture texture = null;
try {
texture = TextureLoader.getTexture("png", Main.class.getResourceAsStream("tex.png"));
} catch (Exception ex) {
ex.printStackTrace();
}
while (!Display.isCloseRequested()) {
// Draw a Triangle :D
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
GL11.glLoadIdentity();
GL11.glTranslatef(0.0f, 0.0f, -10.0f);
GL11.glRotatef(rtri, 0.0f, 1.0f, 0.0f);
texture.bind();
GL11.glBegin(GL11.GL_TRIANGLES);
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(0.0f, 1.0f, 0.0f);
GL11.glTexCoord2f(-1.0f, -1.0f);
GL11.glVertex3f(-1.0f, -1.0f, 1.0f);
GL11.glTexCoord2f(1.0f, -1.0f);
GL11.glVertex3f(1.0f, -1.0f, 1.0f);
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(0.0f, 1.0f, 0.0f);
GL11.glTexCoord2f(-1.0f, -1.0f);
GL11.glVertex3f(1.0f, -1.0f, 1.0f);
GL11.glTexCoord2f(1.0f, -1.0f);
GL11.glVertex3f(1.0f, -1.0f, -1.0f);
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(0.0f, 1.0f, 0.0f);
GL11.glTexCoord2f(-1.0f, -1.0f);
GL11.glVertex3f(-1.0f, -1.0f, -1.0f);
GL11.glTexCoord2f(1.0f, -1.0f);
GL11.glVertex3f(1.0f, -1.0f, -1.0f);
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(0.0f, 1.0f, 0.0f);
GL11.glTexCoord2f(-1.0f, -1.0f);
GL11.glVertex3f(-1.0f, -1.0f, -1.0f);
GL11.glTexCoord2f(1.0f, -1.0f);
GL11.glVertex3f(-1.0f, -1.0f, 1.0f);
GL11.glEnd();
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex3f(1.0f, -1.0f, 1.0f);
GL11.glVertex3f(1.0f, -1.0f, -1.0f);
GL11.glVertex3f(-1.0f, -1.0f, -1.0f);
GL11.glVertex3f(-1.0f, -1.0f, 1.0f);
GL11.glEnd();
Display.update();
rtri += 0.05f;
// Exit-Key = ESC
boolean exitPressed = Keyboard.isKeyDown(Keyboard.KEY_ESCAPE);
if (exitPressed) {
System.out.println("Escape was pressed!");
Display.destroy();
}
}
Display.destroy();
}
private static void initGL() {
GL11.glEnable(GL11.GL_LIGHTING);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GLU.gluPerspective(45.0f, ((float) 800) / ((float) 600), 0.1f, 100.0f);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glShadeModel(GL11.GL_SMOOTH);
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glClearDepth(1.0f);
GL11.glEnable(GL11.GL_DEPTH_TEST);
GL11.glDepthFunc(GL11.GL_LEQUAL);
GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST);
float lightAmbient[] = {0.5f, 0.5f, 0.5f, 1.0f}; // Ambient Light Values
float lightDiffuse[] = {1.0f, 1.0f, 1.0f, 1.0f}; // Diffuse Light Values
float lightPosition[] = {0.0f, 0.0f, 2.0f, 1.0f}; // Light Position
ByteBuffer temp = ByteBuffer.allocateDirect(16);
temp.order(ByteOrder.nativeOrder());
GL11.glLight(GL11.GL_LIGHT1, GL11.GL_AMBIENT, (FloatBuffer) temp.asFloatBuffer().put(lightAmbient).flip()); // Setup The Ambient Light
GL11.glLight(GL11.GL_LIGHT1, GL11.GL_DIFFUSE, (FloatBuffer) temp.asFloatBuffer().put(lightDiffuse).flip()); // Setup The Diffuse Light
GL11.glLight(GL11.GL_LIGHT1, GL11.GL_POSITION, (FloatBuffer) temp.asFloatBuffer().put(lightPosition).flip()); // Position The Light
GL11.glEnable(GL11.GL_LIGHT1); // Enable Light One
}
}
