YJ week16

 內插、攝影機運鏡

1 . Excel 學習內插

-> time : 0.0 ....... 1.0

     alpha : 0.0 ....... 1.0

     angle : 13 ....... 90

-> 內插公式 :  alpha *新的 + (1-alpha) *舊的

2. 來寫程式

-> 建立新GLUT專案

-> 複製上週week1_TRT_angles_again,稍作修改

-> 變成按下"p"可以一直讀檔,連續播放動作

#include <GL/glut.h>

#include <stdio.h>

float angle[20], oldX=0;

int angleID=0; ///0:第0個關節，1:第一個關節，2:第二個關節

FILE*fout=NULL, *fin=NULL;

void myWrite()

{

    if(fin != NULL){

        fclose(fin);

        fin = NULL;

    }

    if(fout==NULL) fout=fopen("file.txt", "w+");

    for(int i=0; i<20; i++){

        printf(      "%.2f" , angle[i]);

        fprintf(fout, "%.2f", angle[i]);

    }

    printf("\n");

    fprintf(fout,"\n");

}

float NewAngle[20],OldAngle[20];

void myRead()

{

    if(fout!=NULL)

    {

fclose(fout);

fout=NULL;

    }

    if(fin==NULL) fin=fopen("file.txt", "r");

    for(int i=0; i<20; i++){

        OldAngle[i] = NewAngle [i];

        fscanf(fin,"%f",&NewAngle[i]);

        ///fscanf(fin,"%f",&angle[i]);

    }

    glutPostRedisplay(); ///重畫畫面

}

void myInterpolate(float alpha)

{

    for(int i=0 ;i<20 ;i++){

        angle[i] =alpha * NewAngle[i] + (1-alpha) * OldAngle[i];

        printf("%.2f",angle[i]);

    }

    printf("\n");

    glutPostRedisplay();

}

float alpha = 0;

void keyboard(unsigned char key,int x,int y)

{

     if(key=='p'){

        myInterpolate(alpha);

        alpha =(alpha+0.1);

        if(alpha>1) alpha = alpha-1;

    }

    if(key=='r')myRead();

    if(key=='s')myWrite(); ///save

    if(key=='0')angleID=0; ///預設這是第一個

    if(key=='1')angleID=1;

    if(key=='2')angleID=2;

    if(key=='3')angleID=3;

}

void mouse(int button, int state , int x, int y) ///mouse按下去

{

    oldX = x;

}

void motion(int x,int y)

{

    angle[angleID] += (x-oldX);

    ///myWrite(); ///沒有必要一直寫檔

    oldX=x;

    glutPostRedisplay();

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glColor3f(1,1,1); ///白色

    glRectf(0.3,0.5,-0.3,-0.2);

    glPushMatrix();

        glTranslatef(0.3,0.5,0); ///掛在0.5,0.5

        glRotatef(angle[0],0,0,1);

        glTranslatef(-0.3,-0.4,0);

        glColor3f(1,0,0); ///紅色

        glRectf(0.3,0.5,0.8,0.3); ///右上手臂

        glPushMatrix();

        glTranslatef(0.8,0.4,0);

        glRotatef(angle[1],0,0,1);

        glTranslatef(-0.8,-0.4,0);

        glColor3f(0,1,0); ///綠色

        glRectf(0.8,0.5,1.1,0.3);

        glPopMatrix();

    glPopMatrix();

    glPushMatrix(); ///左半邊

        glTranslatef(-0.3,0.5,0); ///掛在0.5,0.5

        glRotatef(angle[2],0,0,1);

        glTranslatef(+0.3,-0.4,0);

        glColor3f(1,0,0); ///紅色

        glRectf(-0.3,0.5,-0.8,0.3); ///左上手臂

        glPushMatrix();

        glTranslatef(-0.8,0.4,0);

        glRotatef(angle[3],0,0,1);

        glTranslatef(+0.8,-0.4,0);

        glColor3f(0,1,0); ///綠色

        glRectf(-0.8,0.5,-1.1,0.3); ///左下手肘

        glPopMatrix();

    glPopMatrix();

    glutSwapBuffers();

}

int main(int argc,char ** argv)

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutInitWindowSize(600,600);

    glutCreateWindow("Week14 interpolation");

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutKeyboardFunc(keyboard);

    glutDisplayFunc(display);

    glutMainLoop();

}

3. 利用timer 自動做內插

-> 加上timer , 利用glutTimerFunc(0,timer,0); 開始播放

-> 在if (key =='p') 進行 play

-> 先myRead(); 再註冊timer

-> void timer(t) 裡面做的事 : 依照時間,算出適當的alpha

#include <GL/glut.h>

#include <stdio.h>

float angle[20], oldX=0;

int angleID=0; ///0:第0個關節，1:第一個關節，2:第二個關節

FILE*fout=NULL, *fin=NULL;

void myWrite()

{

    if(fin != NULL){

        fclose(fin);

        fin = NULL;

    }

    if(fout==NULL) fout=fopen("file.txt", "w+");

    for(int i=0; i<20; i++){

        printf(      "%.2f" , angle[i]);

        fprintf(fout, "%.2f", angle[i]);

    }

    printf("\n");

    fprintf(fout,"\n");

}

float NewAngle[20],OldAngle[20];

void myRead()

{

    if(fout!=NULL)

    {

fclose(fout);

fout=NULL;

    }

    if(fin==NULL) fin=fopen("file.txt", "r");

    for(int i=0; i<20; i++){

        OldAngle[i] = NewAngle [i];

        fscanf(fin,"%f",&NewAngle[i]);

        ///fscanf(fin,"%f",&angle[i]);

    }

    glutPostRedisplay(); ///重畫畫面

}

void myInterpolate(float alpha)

{

    for(int i=0 ;i<20 ;i++){

        angle[i] =alpha * NewAngle[i] + (1-alpha) * OldAngle[i];

        printf("%.2f",angle[i]);

    }

    printf("\n");

    glutPostRedisplay();

}

///float alpha = 0;

void timer(int t)

{

    float alpha =(t%30)/30.0;

    if(t%30==0) myRead(); ///遇到30整除時,做新舊交接

    myInterpolate(alpha);

    glutTimerFunc(33,timer,t+1);

}

void keyboard(unsigned char key,int x,int y)

{

    if(key=='p'){ ///play

        myRead(); ///先讀一行

        glutTimerFunc(0,timer,0); ///馬上開始播動畫

        ///myInterpolate(alpha);

        ///alpha =(alpha+0.1);

        ///if(alpha>1) alpha = alpha-1;

    }

    if(key=='r')myRead();

    if(key=='s')myWrite(); ///save

    if(key=='0')angleID=0; ///預設這是第一個

    if(key=='1')angleID=1;

    if(key=='2')angleID=2;

    if(key=='3')angleID=3;

}

void mouse(int button, int state , int x, int y) ///mouse按下去

{

    oldX = x;

}

void motion(int x,int y)

{

    angle[angleID] += (x-oldX);

    ///myWrite(); ///沒有必要一直寫檔

    oldX=x;

    glutPostRedisplay();

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glColor3f(1,1,1); ///白色

    glRectf(0.3,0.5,-0.3,-0.2);

    glPushMatrix();

        glTranslatef(0.3,0.5,0); ///掛在0.5,0.5

        glRotatef(angle[0],0,0,1);

        glTranslatef(-0.3,-0.4,0);

        glColor3f(1,0,0); ///紅色

        glRectf(0.3,0.5,0.8,0.3); ///右上手臂

        glPushMatrix();

        glTranslatef(0.8,0.4,0);

        glRotatef(angle[1],0,0,1);

        glTranslatef(-0.8,-0.4,0);

        glColor3f(0,1,0); ///綠色

        glRectf(0.8,0.5,1.1,0.3);

        glPopMatrix();

    glPopMatrix();

    glPushMatrix(); ///左半邊

        glTranslatef(-0.3,0.5,0); ///掛在0.5,0.5

        glRotatef(angle[2],0,0,1);

        glTranslatef(+0.3,-0.4,0);

        glColor3f(1,0,0); ///紅色

        glRectf(-0.3,0.5,-0.8,0.3); ///左上手臂

        glPushMatrix();

        glTranslatef(-0.8,0.4,0);

        glRotatef(angle[3],0,0,1);

        glTranslatef(+0.8,-0.4,0);

        glColor3f(0,1,0); ///綠色

        glRectf(-0.8,0.5,-1.1,0.3); ///左下手肘

        glPopMatrix();

    glPopMatrix();

    glutSwapBuffers();

}

int main(int argc,char ** argv)

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutInitWindowSize(600,600);

    glutCreateWindow("Week14 interpolation");

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutKeyboardFunc(keyboard);

    glutDisplayFunc(display);

    glutMainLoop();

}

-> float alpha = 0不要是因為會跟void myInterpolate裡的alpha撞 , 所以把它放到timer去做

4. 了解camera調整角度 

-> 到https://jsyeh.org/3dcg10/

-> 下載win32 、 data , 把data資料夾放進windows

-> 打開Projection.exe

5. 調整camera角度和視角的實作

->建立新GLUT專案

#include <GL/glut.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glutSolidTeapot(2); ///大茶壼

    glutSwapBuffers();

}

void motion(int x, int y)

{

    glMatrixMode(GL_MODELVIEW); ///3D經過轉換到你最後的攝影機

    glLoadIdentity();

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

                0, 0, 0, ///center

                0, 1, 0); ///up

    glutPostRedisplay();

}

void reshape(int w, int h)

{

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

    glViewport(0, 0, w, h);

    glMatrixMode(GL_PROJECTION); ///投影,把3D投射到2D畫面

    glLoadIdentity();

    gluPerspective(60, ar, 0.1, 100);

    glMatrixMode(GL_MODELVIEW); ///3D經過轉換到你最後的攝影機

    glLoadIdentity() ;

    gluLookAt( 0, 0, 3, 0, 0, 0, 0, 1, 0);

}

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();

}