Odd 3D Invis Objects?

Ok, i am using a Glut Shell if you will, that i was shown on these forums. Just incase you notice lol :p.

My problem is this, i am using glut and taking NeHe tutorials, i am checkin out lesson 05, making 3d objects rotate.

Now i have made simple 3d objects before, however i have never encountered this. For some reason they are invis, and this is my first time using this glut shell. So i assume it is the shell but i have no idea what would cause this.

And let me restate that about the invisible objects, there is a triangle and a cube, the triangle, made up of 4 other triangles to form the 3d object; then the cube, 6 quads. Very simple, each of them also have some color.

Now the problem is that some of the triangles/quads (the flat triangles/quads ofcourse) seem to be partially invisible, and on the cube where there is solid colors, it looks almost as if certin colors overlap to disapear and junk like that. I am sure you are confused, i dont know really how to explain it. Basically some sides on these 3d pbjects are partially invisible to me, any ideas why? Here is the following code.

Code:

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//#include <windows.h>
#include <iostream>
#include <gl\gl.h>
#include <gl\glut.h>

    GLfloat                rquad;
    GLfloat                rtri;
   
    void draw();


// process menu option 'op'
void menu(int op) {

  switch(op) {
  case 'Q':
  case 'q':
    exit(0);
  }
}

// executed when a regular key is pressed
void keyboardDown(unsigned char key, int x, int y) {

  switch(key) {
  case 'Q':
  case 'q':
  case  27:  // ESC
    exit(0);
  }
}

// executed when a regular key is released
void keyboardUp(unsigned char key, int x, int y) {

}

// executed when a special key is pressed
void keyboardSpecialDown(int k, int x, int y) {

}

// executed when a special key is released
void keyboardSpecialUp(int k, int x, int y) {

}

// reshaped window
void reshape(int width, int height) {

  GLfloat fieldOfView = 90.0f;
  glViewport (0, 0, (GLsizei) width, (GLsizei) height);

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(fieldOfView, (GLfloat) width/(GLfloat) height, 0.1, 500.0);

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}


void mouseClick(int button, int state, int x, int y) {

}

void mouseMotion(int x, int y) {

}

// executed when program is idle
void idle() {
    draw();
}

// render the scene
void draw() {

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glTranslatef(-1.5f,0.0f,-6.0f);       
 
  glRotatef(rtri,0.0f,1.0f,0.0f);
  glBegin(GL_TRIANGLES);                                        // Start Drawing A Triangle
                glColor3f(1.0f,0.0f,0.0f);                        // Red
                glVertex3f( 0.0f, 1.0f, 0.0f);                        // Top Of Triangle (Front)
                glColor3f(0.0f,1.0f,0.0f);                        // Green
                glVertex3f(-1.0f,-1.0f, 1.0f);                        // Left Of Triangle (Front)
                glColor3f(0.0f,0.0f,1.0f);                        // Blue
                glVertex3f( 1.0f,-1.0f, 1.0f);                        // Right Of Triangle (Front)

                glColor3f(1.0f,0.0f,0.0f);                        // Red
                glVertex3f( 0.0f, 1.0f, 0.0f);                        // Top Of Triangle (Right)
                glColor3f(0.0f,0.0f,1.0f);                        // Blue
                glVertex3f( 1.0f,-1.0f, 1.0f);                        // Left Of Triangle (Right)
                glColor3f(0.0f,1.0f,0.0f);                        // Green
                glVertex3f( 1.0f,-1.0f, -1.0f);                        // Right Of Triangle (Right)

                glColor3f(1.0f,0.0f,0.0f);                        // Red
                glVertex3f( 0.0f, 1.0f, 0.0f);                        // Top Of Triangle (Back)
                glColor3f(0.0f,1.0f,0.0f);                        // Green
                glVertex3f( 1.0f,-1.0f, -1.0f);                        // Left Of Triangle (Back)
                glColor3f(0.0f,0.0f,1.0f);                        // Blue
                glVertex3f(-1.0f,-1.0f, -1.0f);                        // Right Of Triangle (Back)

                glColor3f(1.0f,0.0f,0.0f);                        // Red
                glVertex3f( 0.0f, 1.0f, 0.0f);                        // Top Of Triangle (Left)
                glColor3f(0.0f,0.0f,1.0f);                        // Blue
                glVertex3f(-1.0f,-1.0f,-1.0f);                        // Left Of Triangle (Left)
                glColor3f(0.0f,1.0f,0.0f);                        // Green
                glVertex3f(-1.0f,-1.0f, 1.0f);                        // Right Of Triangle (Left)
  glEnd();
 
  glLoadIdentity();                                        // Reset The Current Modelview Matrix
  glTranslatef(1.5f,0.0f,-6.0f);                                // Move Right 1.5 Units And Into The Screen 6.0
  glRotatef(rquad,1.0f,0.0f,0.0f);                        // Rotate The Quad On The X axis ( NEW )
 
        glColor3f(0.5f,0.5f,1.0f);                                // Set The Color To A Nice Blue Shade
        glBegin(GL_QUADS);                                        // Start Drawing A Quad
                glColor3f(0.0f,1.0f,0.0f);                        // Set The Color To Green
                glVertex3f( 1.0f, 1.0f,-1.0f);                        // Top Right Of The Quad (Top)
                glVertex3f(-1.0f, 1.0f,-1.0f);                        // Top Left Of The Quad (Top)
                glVertex3f(-1.0f, 1.0f, 1.0f);                        // Bottom Left Of The Quad (Top)
                glVertex3f( 1.0f, 1.0f, 1.0f);                        // Bottom Right Of The Quad (Top)

                glColor3f(1.0f,0.5f,0.0f);                        // Set The Color To Orange
                glVertex3f( 1.0f,-1.0f, 1.0f);                        // Top Right Of The Quad (Bottom)
                glVertex3f(-1.0f,-1.0f, 1.0f);                        // Top Left Of The Quad (Bottom)
                glVertex3f(-1.0f,-1.0f,-1.0f);                        // Bottom Left Of The Quad (Bottom)
                glVertex3f( 1.0f,-1.0f,-1.0f);                        // Bottom Right Of The Quad (Bottom)
               
                glColor3f(1.0f,0.0f,0.0f);                        // Set The Color To Red
                glVertex3f( 1.0f, 1.0f, 1.0f);                        // Top Right Of The Quad (Front)
                glVertex3f(-1.0f, 1.0f, 1.0f);                        // Top Left Of The Quad (Front)
                glVertex3f(-1.0f,-1.0f, 1.0f);                        // Bottom Left Of The Quad (Front)
                glVertex3f( 1.0f,-1.0f, 1.0f);                        // Bottom Right Of The Quad (Front)

                glColor3f(1.0f,1.0f,0.0f);                        // Set The Color To Yellow
                glVertex3f( 1.0f,-1.0f,-1.0f);                        // Bottom Left Of The Quad (Back)
                glVertex3f(-1.0f,-1.0f,-1.0f);                        // Bottom Right Of The Quad (Back)
                glVertex3f(-1.0f, 1.0f,-1.0f);                        // Top Right Of The Quad (Back)
                glVertex3f( 1.0f, 1.0f,-1.0f);                        // Top Left Of The Quad (Back)
               
                glColor3f(0.0f,0.0f,1.0f);                        // Set The Color To Blue
                glVertex3f(-1.0f, 1.0f, 1.0f);                        // Top Right Of The Quad (Left)
                glVertex3f(-1.0f, 1.0f,-1.0f);                        // Top Left Of The Quad (Left)
                glVertex3f(-1.0f,-1.0f,-1.0f);                        // Bottom Left Of The Quad (Left)
                glVertex3f(-1.0f,-1.0f, 1.0f);                        // Bottom Right Of The Quad (Left)

                glColor3f(1.0f,0.0f,1.0f);                        // Set The Color To Violet
                glVertex3f( 1.0f, 1.0f,-1.0f);                        // Top Right Of The Quad (Right)
                glVertex3f( 1.0f, 1.0f, 1.0f);                        // Top Left Of The Quad (Right)
                glVertex3f( 1.0f,-1.0f, 1.0f);                        // Bottom Left Of The Quad (Right)
                glVertex3f( 1.0f,-1.0f,-1.0f);                        // Bottom Right Of The Quad (Right)
        glEnd();                                                // Done Drawing The Quad

 
  glFlush();
  glutSwapBuffers();
  rtri+=0.2f;
  rquad-=0.15f;
}

// initialize OpenGL settings
void initGL(int width, int height) {

  reshape(width, height);

  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
  glClearDepth(1.0f);
}

// initialize GLUT settings, register callbacks, enter main loop
int main(int argc, char** argv) {
 
  glutInit(&argc, argv);

  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutInitWindowSize(800, 600);
  glutInitWindowPosition(100, 100);
  glutCreateWindow("EmptyGLUT");

  // register glut call backs
  glutKeyboardFunc(keyboardDown);
  glutKeyboardUpFunc(keyboardUp);
  glutSpecialFunc(keyboardSpecialDown);
  glutSpecialUpFunc(keyboardSpecialUp);
  glutMouseFunc(mouseClick);
  glutMotionFunc(mouseMotion);
  glutReshapeFunc(reshape);
  glutDisplayFunc(draw); 
  glutIdleFunc(idle);
  glutIgnoreKeyRepeat(true); // ignore keys held down

  // create a sub menu
  int subMenu = glutCreateMenu(menu);
  glutAddMenuEntry("Do nothing", 0);
  glutAddMenuEntry("Really Quit", 'q');

  // create main "right click" menu
  glutCreateMenu(menu);
  glutAddSubMenu("Sub Menu", subMenu);
  glutAddMenuEntry("Quit", 'q');
  glutAttachMenu(GLUT_RIGHT_BUTTON);

  initGL(800, 600);

  glutMainLoop();
  return 0;
}

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Also i know i am not using any of the key commands and junk so its wasted code, like i said its just a glut overall shell program. Anyway, any ideas on why some are partially invisible?

If there is anything else you need to know please ask, umm, i am using Dev C++, 4.9.9.0. Glut version 3.7 (beta i believe), from the main opengl website. But like i said iv made a bunch of the same type of 3D objects and i havent seen this partial invisibility thing before.

Hope i have given you enough information to help, thanks for any replies :)

A screenshot of the problem would be nice.

Just hit PrtScrn - paste to your fav paint program, resample to 640x480 and convert to JPG. Click manage attachments when you post and browse to the JPG file you just created.

That GLUT framework doesnt configure your openGL rendering states. In this case you need to enable depth testing. Put this in your initGL() function

Code:

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glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);

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on an unrelated note: yay! someones getting some use out of the GLUT template i posted! :D

lol yup :), but thanks, i'll test it tomorrow, hope it fixes it hehe :)

FYI, yes it fixed it, thx :)