display 3D space

[lonbame]

I have a program showing 3D space as follows:

 
#include <conio.h>
#include <graphics.h>
#include <math.h>
 
typedef struct {
  double x, y, z;
} Point3D;
 
double yaw, roll, pitch, depth;
static Point3D p[] = {
{-35.0, -35.0, 35.0},
{35.0, -35.0, 35.0},
{35.0, 35.0, 35.0},
{-35.0, 35.0, 35.0},
{-35.0, -35.0, 35.0},
{-35.0, -35.0, -35.0},
{35.0, -35.0, -35.0},
{35.0, 35.0, -35.0},
{-35.0, 35.0, -35.0},
{-35.0, -35.0, -35.0}
};
 
void show_3d(Point3D p[], int n)
{
  double sinyaw, cosyaw, sinroll, cosroll, sinpitch, cospitch,
     yawx, yawy, rollx, rollz, pitchx, pitchy, pitchz, sx, sy;
  int r;
 
  cleardevice();
 
  sinyaw = sin(yaw);
  cosyaw = cos(yaw);
  sinroll = sin(roll);
  cosroll = cos(roll);
  sinpitch = sin(pitch);
  cospitch = cos(pitch);
 
  for (r=0; r<n; r++)
  {
    yawx = (cosyaw * p[r].x) - (sinyaw * p[r].y);
    yawy = (sinyaw * p[r].x) + (cosyaw * p[r].y);
    rollx = (cosroll * yawx) + (sinroll * p[r].z);
    rollz = (cosroll * p[r].z) - (sinroll * p[r].z);
    pitchy = (cospitch * yawy) - (sinpitch * rollz);
    pitchz = (sinpitch * yawy) + (cospitch * rollz);
 
    sx = depth * (rollx+5) / (pitchy+250);
    sy = depth * (pitchz-5) / (pitchy+250);
    if (r == 0)
      moveto(sx+getmaxx() / 2, sy + getmaxy() / 2);
    else
      lineto(sx+getmaxx() / 2, sy+getmaxy() / 2);
  }
}
 
void main()
{
  int gr_drive = DETECT, gr_mode, c=0;
 
  initgraph(&gr_drive, &gr_mode, "C:\\TC\\BGI");
 
  yaw = 5.7;
  roll = 6.3;
  pitch = 5.9;
  depth = 360;
  while (c != 27)
  {
    show_3d(p, 10);
    c = getch();
    if (c==0)
      c = getch();
    switch (c)
    {
      case 75 : yaw -= 0.1;
        break;
      case 77 : yaw += 0.1;
        break;
      case 72 : pitch -= 0.1;
        break;
      case 80 : pitch += 0.1;
        break;
    }
  }
  closegraph();
  getch();
}
 

How to apply effects to the image??

[JosAH]

@lonbame
What effects? All you do now is display a projection of a three dimensional 'connect the dots' wire figure.

kind regards,

Jos

[RRick]

Welcome to the world of 3D graphics. Most people's first attempt is some kind of wire frame representation of an object. Jos is right in that points and lines don't lend themselves to advanced effects like texturing, shading and lighting.

For those effects you need some kind of surface like a triangle or quadratic. But these polygon primitives add a new set of problems beyond rendering, like who's in front of who (hidden line removal), pixel to pixel shading and texturing.

Which way you go forward from here depends on what you are interested in. If you like the low level algorithms, then keep on the same track as you are right now. You'll learn a lot as you go along.

If you are more interested in the end product, then a 3D toolkit/framework is the best way to go. There is opengl open source and Directx->Direct3D for windows. Each of these toolkits provide you with functions for the manipulating 3D objects.