看一下幫助,裡面有 X<`
INTERFACE r [ t m m'] ? x=hiQ>BIO0
COAT k coat coat' i&Tbz!
-k |+FubYf?$
+k HZzD VCU
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. zl>nSndRE
+ 指只有折射沒有反射光, G~^r)fm_
- 指只有反射沒有折射。