正确使用gluLookAt()吗?

时间:2019-05-20 12:59:57

标签: c opengl glut opengl-compat

我正在尝试使用gluLookAt()

设置视角

这里有我的代码,试图将相机设置为无结果

这里的功能displaycone()

void displayCone(void)
{

    glMatrixMode(GL_MODELVIEW);
    // clear the drawing buffer.
    glClear(GL_COLOR_BUFFER_BIT);
    // clear the identity matrix.
    glLoadIdentity();
    // traslate the draw by z = -4.0
    // Note this when you decrease z like -8.0 the drawing will looks       far , or smaller.
    glTranslatef(0.0,0.0,-4.5);
    // Red color used to draw.
    glColor3f(0.8, 0.2, 0.1);
    // changing in transformation matrix.
    // rotation about X axis
    glRotatef(xRotated,1.0,0.0,0.0);
    // rotation about Y axis
    glRotatef(yRotated,0.0,1.0,0.0);
    // rotation about Z axis
    glRotatef(zRotated,0.0,0.0,1.0);

    // scaling transfomation
    glScalef(1.0,1.0,1.0);
    // built-in (glut library) function , draw you a Cone.

    // move the peak of the cone to the origin
    glTranslatef(0.0, 0.0, -height);

    glutSolidCone(base,height,slices,stacks);
    // Flush buffers to screen
    gluLookAt(3,3,3,0,0,-4.5,0,1,0);

    glFlush();
    // sawp buffers called because we are using double buffering
    // glutSwapBuffers();
}

我的主语:

int main (int argc, char **argv)
{
    glutInit(&argc, argv);
    //double buffering used to avoid flickering problem in animation
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    // window size
    glutInitWindowSize(400,350);

    // create the window
    glutCreateWindow("Cone Rotating Animation");
    glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);

    glClearColor(0.0,0.0,0.0,0.0);
    //Assign  the function used in events

    glutDisplayFunc(displayCone);
    glutReshapeFunc(reshapeCone);
    glutIdleFunc(idleCone);
    //Let start glut loop
    glutMainLoop();
    return 0;
}

函数idlecone会更改xRotatedyRotated ...的值并显示圆锥。有什么想法吗?

我很确定我不了解在正确的时间使用gluLookAt() ...

1 个答案:

答案 0 :(得分:2)

gluLookAt更改当前矩阵,类似于@RestControllerAdvice public class GlobalExceptionHandler { @ExceptionHandler(FeignException.class) public String handleFeignStatusException(FeignException e, HttpServletResponse response) { response.setStatus(e.status()); return "feignError"; } } response.getOutputStream().write(e.content());
该操作定义了一个转换矩阵,并将当前矩阵乘以新的转换矩阵。

glTranslatef必须在glRotatef之前调用,例如:

gluLookAt
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