Week15

攝影機與運鏡

去 http://www.cmlab.csie.ntu.edu.tw/~jsyeh/3dcg10/ 載 data , windows , glut32.dll

gluPerspective()

開glut檔 修改程式碼
改resize()函式裡面的glFrustum()變成gluPerspective()



gluPerspective()裡面的aspect ratio用 ar=寬度除高度,就可以順利做出來

glOrtho()

用透視投影gluPerspective()來看茶壼




把剛剛的茶壼程式
加glutMotionFunc(motion),在void motion(int x, int y)裡, 改變eyeX,eyeY
再用3行,去修改gluLookAt()

#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>

static int slices = 16;
static int stacks = 16;

float eyeX=0, eyeY=0, eyeZ=1; ///TODO3 for gluLookAt()
float centerX=0, centerY=0, centerZ=0;///TODO3 for gluLookAt()
static void resize(int width, int height)
{
    const float ar = (float) width / (float) height;

    glViewport(0, 0, width, height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    ///glFrustum(-ar, ar, -1.0, 1.0, 2.0, 100.0);
    gluPerspective( 60, ar, 0.001, 1000 );///TODO3
    ///glOrtho(-1,+1, -1,+1, -1,+1);///預設值,很限制
    ///glOrtho(-3.4, +3.4,  -2.2, +2.2, -6.0, +16.0);///TODO2

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity() ;///TODO3 for gluLookAt()
    gluLookAt(eyeX,eyeY,eyeZ, centerX,centerY,centerZ, 0,1,0);
}

static void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glutSolidTeapot(0.3);///TODO3,只放我們的Teapot

    glutSwapBuffers();
}

///key全刪....

static void idle(void)
{
    ///TODO3: 等一下要在這裡做動作....
    glutPostRedisplay();
}

const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_position[] = { 2.0f, 5.0f, 5.0f, 0.0f };

const GLfloat mat_ambient[]    = { 0.7f, 0.7f, 0.7f, 1.0f };
const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[]   = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat high_shininess[] = { 100.0f };

void motion(int x,int y)
{
    eyeX = (x-320)/320.0;
    eyeY = (y-240)/240.0;
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(eyeX,eyeY,eyeZ, centerX, centerY, centerZ, 0,1,0);
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitWindowSize(640,480);
    glutInitWindowPosition(10,10);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    glutReshapeFunc(resize);
    glutDisplayFunc(display);
    ///glutKeyboardFunc(key);
    glutIdleFunc(idle);
    glutMotionFunc(motion);

    glClearColor(1,1,1,1);

    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);

    glEnable(GL_LIGHT0);
    glEnable(GL_NORMALIZE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHTING);

    glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glMaterialfv(GL_FRONT, GL_AMBIENT,   mat_ambient);
    glMaterialfv(GL_FRONT, GL_DIFFUSE,   mat_diffuse);
    glMaterialfv(GL_FRONT, GL_SPECULAR,  mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);

    glutMainLoop();

    return EXIT_SUCCESS;
}