看一下幫助,裡面有 s=>^ 8[0O
INTERFACE r [ t m m'] ? U'LPaf$O
COAT k coat coat' :{s0tw>Z
-k }z F,dst
+k :(YFIW`59
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. &fW'_,-
+ 指只有折射沒有反射光, wv
- 指只有反射沒有折射。