Basic OpenGL Rendering using LWJGL can't see a 3Dcube...

[ibelieve]

hi everybody i used your source Basic "OpenGL Rendering using LWJGL" to start opengl under java....
it 's useful but i had some problems when i made some changes...
in fact i want to make a cube but it doesn t work well, when i modify the gluLookAt parameters, i only see lines but not faces of my cube...
could you help me ?

that's my render

/**
   * Render the current frame
   */
  private static void render() {
    // clear the screen
	GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);
    GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
 
    // center square according to screen size
    GL11.glPushMatrix();
    GL11.glTranslatef(Display.getDisplayMode().getWidth() / 2, Display.getDisplayMode().getHeight() / 2, 0.0f);
 
      // rotate square according to angle
     GL11.glRotatef(angle, 0, 0, 1.0f);
 
      // render the square
    
     GL11.glMatrixMode(GL11.GL_MODELVIEW);
     GLU.gluLookAt(1,1,1,0,0,0,1,1,0);
      
      GL11.glBegin(GL11.GL_QUADS);

    
      GL11.glColor3d(1,0,0);
      GL11.glVertex3i(50,50,50);
      GL11.glVertex3i(50,-50,50);
      GL11.glVertex3i(-50,-50,50);
      GL11.glVertex3i(-50,50,50);
      	//1 face
      
      GL11.glColor3d(0,1,0);
      GL11.glVertex3i(50,50,-50);
      GL11.glVertex3i(50,-50,-50);
      GL11.glVertex3i(-50,-50,-50);
      GL11.glVertex3i(-50,50,-50);
      	//2 faces

      GL11.glColor3d(0,0,1);
      GL11.glVertex3i(50,50,50);
      GL11.glVertex3i(50,-50,50);
      GL11.glVertex3i(50,-50,-50);
      GL11.glVertex3i(50,50,-50);
      	//3 faces
      
      GL11.glColor3d(0,1,1);
      GL11.glVertex3i(-50,50,50);
      GL11.glVertex3i(-50,-50,50);
      GL11.glVertex3i(-50,-50,-50);
      GL11.glVertex3i(-50,50,-50);
      	//4 faces

      GL11.glColor3d(1,0,0);
      GL11.glVertex3i(-50,50,-50);
      GL11.glVertex3i(-50,50,50);
      GL11.glVertex3i(50,50,50);
      GL11.glVertex3i(50,50,-50);
      	//5 faces

      GL11.glColor3d(1,1,0);
      GL11.glVertex3i(-50,-50,-50);
      GL11.glVertex3i(-50,-50,50);
      GL11.glVertex3i(50,-50,50);
      GL11.glVertex3i(50,-50,-50);

      GL11.glEnd();

    GL11.glPopMatrix();
  }

maybe bad parameters in vertex ? or lookat ?
thanks

[mark]

I'm a bit inexperienced myself, but you could try setting

GL11.glPolygonMode(GL11.GL_FRONT,GL11.GL_FILL);

before glBegin. That's the best I can think of.

[Fool Running]

Try putting the code

     // render the square
   
     GL11.glMatrixMode(GL11.GL_MODELVIEW);
     GLU.gluLookAt(1,1,1,0,0,0,1,1,0);

in between the

   GL11.glPushMatrix();
    GL11.glTranslatef(Display.getDisplayMode().getWidth() / 2, Display.getDisplayMode().getHeight() / 2, 0.0f);

and look at the parameters for GLU.gluLookAt()... I think you have some parameters NOT what you want them to be.
(Don't try this if Mark's suggestion works :lol: )

[ibelieve]

thanks but it doen t work...
in fact i try this

GLU.gluPerspective(5f,1f,1f,50f);
instead of glulookat

and it is better...

[Fool Running]

Ok... I think I got something (now that I actually tried it :lol: )
change:

// center square according to screen size
    GL11.glPushMatrix();
    GL11.glTranslatef(Display.getDisplayMode().getWidth() / 2, Display.getDisplayMode().getHeight() / 2, 0.0f);
 
      // rotate square according to angle
     GL11.glRotatef(angle, 0, 0, 1.0f);
 
      // render the square
   
     GL11.glMatrixMode(GL11.GL_MODELVIEW);
     GLU.gluLookAt(1,1,1,0,0,0,1,1,0);

to

       GL11.glMatrixMode(GL_PROJECTION);
        GL11.glLoadIdentity();
        GLU.gluPerspective(45.0f, 1f, 1f, 5000f);
        GL11.glMatrixMode(GL11.GL_MODELVIEW);
        
        GL11.glLoadIdentity();
        
        GL11.glPushMatrix();
        GLU.gluLookAt(0, 0, -1000, 0, 0, 0, 0, 1, 0);

        // rotate square according to angle
        GL11.glRotatef(angle, 0, 0, 1.0f);

I think that should get you started

[darkprophet]

       GL11.glMatrixMode(GL_PROJECTION); 
        GL11.glLoadIdentity(); 
        GLU.gluPerspective(45.0f, 1f, 1f, 5000f); 
        GL11.glMatrixMode(GL11.GL_MODELVIEW); 
        
        GL11.glLoadIdentity(); 
        
        GL11.glPushMatrix(); 
        GLU.gluLookAt(0, 0, -1000, 0, 0, 0, 0, 1, 0); 

        // rotate square according to angle 
        GL11.glRotatef(angle, 0, 0, 1.0f);

You dont need that glPushMatrix in that code. In fact, im surprised it even ran because the stack is incomplete when you switch buffers

DP

[Fool Running]

Its needed because there is a popMatrix() at the end. But, yes, its not really needed unless he starts adding other stuff besides a cube.

[ibelieve]

thanks it is great
I've just made changes in function glulookat (put a value in first parameters)

GLU.gluLookAt(10, 0, -10, 0, 0, 0, 0, 1, 0);

so we have a great cube now
thanks to all
i ll put the source when i finished it, but first i want to change colors when i made a click with my mouse...lol
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