视点变化了，对象选中不了

ts_chen

我想实现opengl场景中对象拾取功能，视点不变即初始场景时可以选取物体，但视点变化之后选中不了，各位高手帮我看看
void CScene:rocessSelection (CPoint point)
{
    GLuint selectBuf[BUFSIZE];//create the selection buffer
    GLint hits;
    GLint viewport[4];//create a viewport
    int x=0;
    int y=0;
    x=point.x;
    y=point.y;
    glGetIntegerv (GL_VIEWPORT, viewport);
    glSelectBuffer (BUFSIZE, selectBuf);
    (void) glRenderMode (GL_SELECT);
    glInitNames();
    glPushName(0);
    glPopName();   
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();
    //setup a pick matrix
    gluPickMatrix ((GLdouble) x, (GLdouble) (viewport[3] - y),
        5, 5, viewport);
    GLdouble aspect(0);
    aspect=(GLdouble)viewport[2]/(GLdouble)viewport[3];
    //gluPerspective(45.0f, aspect, .01f, 200.0f);
    gluPerspective(45.0f, aspect, 0.1,10);
    Render(GL_SELECT);// Draw to the pick matrix instead of our normal one
    glMatrixMode (GL_PROJECTION);
    glPopMatrix ();
    glFlush ();
    hits = glRenderMode (GL_RENDER);
    ProcessObject (selectBuf);
}

ts_chen

我怀疑是gluPerspective(45.0f, aspect, 0.1,10); 的问题，最后这个参数改大了的话也选中不了物体，不知为什么