看一下幫助,裡面有 KN<S}3MN
INTERFACE r [ t m m'] ? R3x3]]D
COAT k coat coat' `uOT+B%R
-k K2TcOFQ
+k B2>H_dmQ
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. 'u *DA|HC
+ 指只有折射沒有反射光, yv t.
- 指只有反射沒有折射。