Question

我有以下场景。

     glMatrixMode (GL_PROJECTION);
     glLoadIdentity ();
     gluPerspective(45, w/h,.1, 100);

     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
     gluLookAt(cameraX,cameraY,cameraZ,0.0,0.0,0.0,0.0,1.0,0.0);

         drawtheBOT();
         drawUserTrackedBall();  // This ball moves in 3d with user controlling it.

当我更改cameraX，cameraY，cameraZ的值时，球的移动也会根据glulookat值而改变。例如，如果我从正x方向看，我的原始左右运动现在将变为近和远的运动。

如何取消外观转换？

Answer 1

glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();

drawUserTrackedBall();

glMatrixMode(GL_MODELVIEW);
glPopMatrix();

或

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

glPushMatrix();
gluLookAt(cameraX,cameraY,cameraZ,0.0,0.0,0.0,0.0,1.0,0.0);
drawtheBOT();

glMatrixMode(GL_MODELVIEW);
glPopMatrix();

drawUserTrackedBall();  // This ball moves in 3d with user controlli

或

glMatrixMode(GL_MODELVIEW);
glLoadMatrix(bot_modelview);
drawtheBOT();

glMatrixMode(GL_MODELVIEW);
glLoadMatrix(ball_modelview);
drawUserTrackedBall();

glMatrixMode的调用并不多余，因为我不知道绘图函数内部会发生什么。

如何反转场景中特定对象的gluLookat变换？

1 个答案: