week16👻

 1.excel內插

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2.打開window/projection,eye是看,center是中心,up攝影機旋轉

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3.調整長寬

aspect radio=寬度/長度

程式碼

#include<GL/glut.h>

void motion(int x,int y)

{

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

    gluLookAt((x-150)/15.0,(y-150)/15.0,3,

              0,0,0,

              0,1,0);

    glutPostRedisplay();

}

 void reshape(int w, int h)

{///aspect ratio

    const float ar = (float) w / (float) h;

    glViewport(0, 0, w, h);

    glMatrixMode(GL_PROJECTION);///投影，把3D投影到2D

    glLoadIdentity();

    gluPerspective(60,ar,0.1,100);

    //glFrustum(, ar, -1.0, 1.0, 2.0, 100.0);

    ///3D經過轉換到你最後的攝影機

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity() ;

    gluLookAt(0,0,3,0,0,0,0,1,0);

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    //glColor3f(1,1,0);

    glutSolidTeapot(1);

    glutSwapBuffers();

}

int main(int argc, char**argv)

{

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

glutCreateWindow("week16 camera lookat");

glutReshapeFunc(reshape);

glutDisplayFunc(display);

glutMotionFunc(motion);

glutMainLoop();

}