看一下幫助，裡面有 (k&aD2PH INTERFACE r [ t m m'] ? w/6@R 4)p COAT k coat coat' S6tH!Z=(g -k `_^=OOn
+k n$l]+[> The signs in front of k can be used to instruct ASAP to either propagate only a reflected ray (-k: t=0) at that object or to propagate only a transmitted ray (+k: r=0) at that object. yo?Q%w'Nh + 指只有折射沒有反射光， UdJV;T'rm - 指只有反射沒有折射。