week11_wendy

電腦圖學 學習日誌

week11

• 主題: OBJ 模型
• 主題: 利用glm讀入OBJ模型
• 進階: OBJ檔、貼圖座標
• 確認作業3(簡單機器手臂)繳交狀況

(一)OBJ模型

首先到以下網址:http://www.cmlab.csie.ntu.edu.tw/~jsyeh/3dcg10/?fbclid=IwAR27zOey6BiJ1AT2bZvAxJJfkbTFXW9S7EJIHNgeYqjKDs2G0VpDDLmXJf8

下載: source、data、win32、glut32.dll
在data中開啟一個obj檔(Notepad++)，了解OBJ檔的內容架構

(二)運用範例建立自己的程(OBJ檔、貼圖座標)

從source開啟3個檔:glm.h、glm.c、transformation.c

1. 新建一個glut專案 ex:week11-1
2. 將glm.h與glm.c檔放到week11-1專案資料夾
3. 改glm.c為glm.cpp
4. 將glm.cpp →add加入project裡
5. 把下載下來的data放入freeglut的bin資料夾中

(三)自己寫一個glut程式入模型


#include <GL/glut.h>
#include "glm.h"


GLMmodel * model=NULL;

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

    if(model == NULL) model = glmReadOBJ("data/Al.obj");
    glmUnitize(model);
    glmFacetNormals(model);
    glmVertexNormals(model,90);
    glmDraw(model, GLM_SMOOTH | GLM_MATERIAL );

    glutSwapBuffers();
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
    glutCreateWindow("week11親手打造");
    glutDisplayFunc(display);

    glutMainLoop();

    return 0;

}



(四)加入打光效果

#include <GL/glut.h>
#include "glm.h"

GLMmodel * model=NULL;

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 display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    if(model == NULL) model = glmReadOBJ("data/Al.obj");
    glmUnitize(model);
    glmFacetNormals(model);
    glmVertexNormals(model,90);
    glmDraw(model, GLM_SMOOTH | GLM_MATERIAL );

    glutSwapBuffers();
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
    glutCreateWindow("week11親手打造");
    glutDisplayFunc(display);

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

    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
    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 0;

}

(四)加入旋轉位移

修改display();程式部分

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

    if(model == NULL){
        model = glmReadOBJ("data/Al.obj");
        glmUnitize(model);
        glmFacetNormals(model);
        glmVertexNormals(model,90);
    }
    glPushMatrix();
        glRotatef(180,0,1,0);
        glmDraw(model, GLM_SMOOTH | GLM_MATERIAL );
    glPopMatrix();
    glutSwapBuffers();

}