如果给定一个模为1的三维矢量,把他显示在球面上的一个点,也就是在一个透视球体上取点,怎样做这个球体并描点<img src="attachments/dvbbs/2006-6/200661610235074699.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2006-6/200661610235074699.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />