void gluPerspective( GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar )
near 和 far 决定了投影参考点与裁剪窗口的距离,fovy决定了裁剪窗口的高度,还有个参数 aspect 确定了裁剪窗口的长宽比例。
所以fovy越大,裁剪窗口越大,相对的裁剪窗口中的物体就越小。
void gluLookAt(GLdouble eyex,GLdouble eyey,GLdouble eyez,GLdouble centerx,GLdouble centery,GLdouble centerz,GLdouble upx,GLdouble upy,GLdouble upz);
正交投影与 glOrtho :void glOrtho(GLdouble left,GLdouble right,GLdouble bottom,GLdouble top,GLdouble near,GLdouble far)
在现场可见量由两个浅蓝色飞机围成块。
透视与 gluPerspective :
void gluPerspective( GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar )
在现场可见卷是由两截断金字塔浅蓝色飞机包围。
透视与 glFrustum :void glFrustum(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble nearVal, GLdouble farVal);