Question

我弄清楚如何放置＆＃34;相机＆＃34;在我创建的立方体内部，我可以像FPS一样移动。我尝试使用gluLookAt和gluPerspective，但我明显错过了一些步骤。在gluLookAt之前我该怎么做？

这是迄今为止编写的代码：

int rotate_Y; //used to rotate the cube about the Y-axis
int rotate_X; //used to rotate the cube about the X-axis

//the display function draws the scene and redraws it
void display(){

    //clear the screen and the z-buffer 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glLoadIdentity(); //resets the transformations

    glRotatef(rotate_X, 1.0, 0.0, 0.0);
    glRotatef(rotate_Y, 0.0, 1.0, 0.0);

    //Front Face of the cube - vertex definition
    glBegin(GL_POLYGON); 
    glColor3f(0.0, 1.0, 0.0);
    glVertex3f(-0.5f, -0.5f, -0.5f);
    glVertex3f(-0.5f, 0.5f, -0.5f);  
    glVertex3f(0.5f, 0.5f, -0.5f);
    glVertex3f(0.5f, -0.5f, -0.5f);
    glEnd();

    //Back Face of the cube - vertex definition
    glBegin(GL_POLYGON);
    glColor3f(1.0, 0.0, 0.0);
    glVertex3f(-0.5f, -0.5f, 0.5f);
    glVertex3f(-0.5f, 0.5f, 0.5f);
    glVertex3f(0.5f, 0.5f, 0.5f);
    glVertex3f(0.5f, -0.5f, 0.5f);
    glEnd();

    //Right Face of the cube - vertex definition
    glBegin(GL_POLYGON);
    glColor3f(1.0, 0.0, 1.0);
    glVertex3f(0.5f, -0.5f, 0.5f);
    glVertex3f(0.5f, 0.5f, 0.5f);
    glVertex3f(0.5f, 0.5f, -0.5f);
    glVertex3f(0.5f, -0.5f, -0.5f);
    glEnd();

    //Left Face of the cube - vertex definition
    glBegin(GL_POLYGON);
    glColor3f(0.7, 0.7, 0.0);
    glVertex3f(-0.5f, -0.5f, -0.5f);
    glVertex3f(-0.5f, 0.5f, -0.5f);
    glVertex3f(-0.5f, 0.5f, 0.5f);
    glVertex3f(-0.5f, -0.5f, 0.5f);
    glEnd();

    //Upper Face of the cube - vertex definition
    glBegin(GL_POLYGON);
    glColor3f(0.7, 0.7, 0.3);
    glVertex3f(-0.5f, 0.5f, 0.5f);
    glVertex3f(-0.5f, 0.5f, -0.5f);
    glVertex3f(0.5f, 0.5f, -0.5f);
    glVertex3f(0.5f, 0.5f, 0.5f);
    glEnd();

    //Bottom Face of the cube - vertex definition
    glBegin(GL_POLYGON);
    glColor3f(0.2, 0.2, 0.8);
    glVertex3f(-0.5f, -0.5f, -0.5f);
    glVertex3f(-0.5f, -0.5f, 0.5f);
    glVertex3f(0.5f, -0.5f, 0.5f);
    glVertex3f(0.5f, -0.5f, -0.5f);
    glEnd();

    glFlush();
    glutSwapBuffers(); //send image to the screen
}

//the special keys function allows interaction via keys (also special ones)
void specialKeys(int key, int x, int y){
    switch (key){
        case GLUT_KEY_F1:
            exit(0);
            break;
        case GLUT_KEY_LEFT:
            rotate_Y -= 5;
            break;
        case GLUT_KEY_UP:
            rotate_X -= 5;
            break;
        case GLUT_KEY_RIGHT:
            rotate_Y += 5;
            break;
        case GLUT_KEY_DOWN:
            rotate_X += 5;
            break;
    }

    glutPostRedisplay(); //request a screen refresh to see changes 

}

int main(int argc, char*argv[]){

    //initialize GLUT 
    glutInit(&argc, argv);

    //request double buffering, RGB colors window and a z-buffer
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);

    //create a window
    glutInitWindowSize(600, 600);
    glutInitWindowPosition(100, 100);
    glutCreateWindow("Space");

    //enable depth
    glEnable(GL_DEPTH_TEST);

    //callback functions
    glutDisplayFunc(display); //display - redraws the scene
    glutSpecialFunc(specialKeys); //special - allows interaction with specialkeys

    //pass control to GLUT for events
    glutMainLoop(); 

    return 0; //this line is never reached
}

Answer 1

您希望使用glTranslatef(float x,float y,float z)来移动相机。

请注意，由于OpenGL的工作原理，转换实际上适用于世界其他地方，而不是相机。因此，上述功能实际上将按照指定的量移动之后绘制的所有内容（而不是相机）。

要让相机移动到某个位置，您需要在将位置传递给函数之前否定该位置的所有组件。这将把世界推向相反的方向，将相机放在你想要的地方。

如何把＃34;相机＆＃34;在OpenGL中的多维数据集内

1 个答案: