alpha=pi/6
theta=pi/4
beta=pi/3
T1=[1,0,0;0,cos(beta),-sin(beta);0,sin(beta),cos(beta)]
T2=[cos(alpha),0,sin(alpha);0,1,0;-sin(alpha),0,cos(alpha)]
T3=[cos(theta),-sin(theta),0;sin(theta),cos(theta),0;0,0,1]
n1=1.5
n2=1.2
x=0:10:100
y=0:10:100
z=0:10:100
F_refraction=[n1/n2x,n1/n2y,-sqrt(1-power((n1/n2),2)+power((n1/n2),2)*power(z,2))]
sr=[x,y,z].*T1.T2.T3F_refractioninv(T1)*inv(T2)*inv(T3)
mesh(x,y,z,sr)