Mohanraj
To perform
3D transformations such as translation, scaling, rotation on 3D object.
ALGORITHM:
1.
Start
2.
Initialize the graphics mode.
3.
Draw a 3D object.
4.
A) Translation
a.
Get the translation value tx, ty
b.
Move the object with tx, ty (x’=x+tx,y’=y+ty, z’=z+tz)
c.
Plot (x’, y’)
5.
B)
Scaling
a.
Get the scaling value Sx,Sy
b.
Resize the object with Sx,Sy (x’=x*Sx,y’=y*Sy)
c.
Plot (x’,y’)
6.
C) Rotation
a.
Get the Rotation angle
b.
Rotate the object by the angle ф
1.
x’=x cos ф - y sin ф
2.
y’=x sin ф - y cosф
c.
Plot (x’,y’)
#include<graphics.h>
#include<process.h>
#include<stdlib.h>
#include<conio.h>
#include<math.h>
#include<stdio.h>
#include<dos.h>
#define x 250
#define y 100
#define z 100
int ori[24];
void wtor(int pts3[24]);
void cube(int pts1[16]);
void main()
{
int gd=DETECT,gm,s,ch;
void tran();
void rot();
void scale();
initgraph(&gd,&gm,"e:\\tc\\bgi");
printf("\n\t\t 3D TRANSFORMATION");
printf("\n ***********************");
printf("\n enter the side of the cube");
scanf("%d",&s);
ori[0]=x;
ori[1]=y; ori[2]=z;
ori[3]=x+s;
ori[4]=y; ori[5]=z;
ori[6]=x+s;
ori[7]=y; ori[8]=z+s;
ori[9]=x;
ori[10]=y; ori[11]=z+s;
ori[12]=x;
ori[13]=y-s; ori[14]=z;
ori[15]=x+s; ori[16]=y-s; ori[17]=z;
ori[18]=x+s; ori[19]=y-s; ori[20]=z+s;
ori[21]=x; ori[22]=y-s; ori[23]=z+s;
wtor(ori);
getch();
do
{
clearviewport();
gotoxy(35,5);
printf("\n\t\t 3d transformation\n");
printf("\n\t\t 1.translation\n");
printf("\n\t\t 2.rotation\n");
printf("\n\t\t 3.scaling\n");
printf("\n\t\t 4.exit");
printf("\n\t\t enter ur choice:\n");
scanf("%d",&ch);
switch(ch)
{
case 1:
wtor(ori);
tran();
getch();
break;
case 2:
wtor(ori);
rot();
getch();
break;
case 3:
wtor(ori);
scale();
getch();
break;
case 4:
break;
default:
printf("\n invalid entry!!!");
getch();
break;
}
}
while(ch!=4);
closegraph();
}
void cube(int pts1[16])
{
setcolor(15);
setlinestyle(DOTTED_LINE,1,1);
line(pts1[0],pts1[1],pts1[2],pts1[3]);
delay(200);
line(pts1[2],pts1[3],pts1[4],pts1[5]);
delay(200);
line(pts1[2],pts1[3],pts1[10],pts1[11]);
delay(200);
setlinestyle(SOLID_LINE,1,1);
line(pts1[4],pts1[5],pts1[6],pts1[7]);
delay(200);
line(pts1[6],pts1[7],pts1[0],pts1[1]);
delay(200);
line(pts1[0],pts1[1],pts1[8],pts1[9]);
delay(200);
line(pts1[4],pts1[5],pts1[12],pts1[13]);
delay(200);
line(pts1[6],pts1[7],pts1[14],pts1[15]);
delay(200);
line(pts1[18],pts1[9],pts1[10],pts1[11]);
delay(200);
line(pts1[10],pts1[11],pts1[12],pts1[13]);
delay(200);
line(pts1[12],pts1[13],pts1[14],pts1[15]);
delay(200);
line(pts1[8],pts1[9],pts1[14],pts1[15]);
delay(200);
setcolor(15);
}
void wtor(int pts3[24])
{
int pts2[16],i,j;
float a1=3.14*60/180;
float a2=3.14*60/180;
for(i=0,j=0;i<24,j<16;i+=3,j+=2)
{
pts2[j]=pts3[i]+pts3[i+2]*1/tan(a1)*cos(a2);
pts2[j+1]=pts3[i+1]+pts3[i+2]*1/tan(a1)*cos(a2);
}
cube(pts2);
}
void tran()
{
int tr3[24];
int i,tx,ty,tz;
printf("\n enter the translation vectors:");
scanf("%d%d%d",&tx,&ty,&tz);
for(i=0;i<24;i+=3)
{
tr3[i]=ori[i]+tx;
tr3[i+1]=ori[i+1]+ty;
tr3[i+2]=ori[i+2]+tz;
}
wtor(tr3);
}
void rot()
{
int r3[24];
float deg,rad;
int i,axis;
printf("enter the angle:");
scanf("%f",°);
rad=3.14*deg/180;
printf("x=1/y=2/z=3:\n");
scanf("%d",&axis);
for(i=0;i<24;i+=3)
{
switch(axis)
{
case 1:
r3[i]=ori[i];
r3[i+1]=ori[i+1]*cos(rad)-ori[i+2]*sin(rad);
r3[i+2]=ori[i+1]*sin(rad)+ori[i+2]*cos(rad);
break;
case 2:
r3[i+3]=ori[i+1];
r3[i]=ori[i+2]*sin(rad)+ori[i]*cos(rad);
r3[i+2]=ori[i+2]*cos(rad)-ori[i+2]*sin(rad);
break;
case 3:
r3[i]=ori[i]*cos(rad)-ori[i+1]*sin(rad);
r3[i+1]=ori[i]*sin(rad)+ori[i+1]*cos(rad);
break;
default:
printf("\n invalid choice!!!");
getch();
break;
}
}
wtor(r3);
}
void scale()
{
float sx,sy,sz;
int i,s3[24];
printf("\n Enter the scaling factor:");
scanf("%f%f%f",&sx,&sy,&sz);
for(i=0;i<24;i+=3)
{
s3[i]=ori[i]*sx;
s3[i+1]=ori[i+1]*sy;
s3[i+2]=ori[i+2]*sz;
}
wtor(s3);
}
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