library(rgl)
v1<-c(0,0,0)
v2<-c(1,0,0)
v3<-c(1,1,0)
v4<-c(0,1,0)
alpha<-0.3
beta1<-0.2
beta2<-0.7
v5<-c(alpha,beta1,0)
v6<-c(alpha,beta2,0)
L<-1.5
v7<-c(alpha,beta2,L)
Vs<-rbind(v1,v2,v3,v4,v5,v6,v7)
plot3d(Vs,xlim=c(-0.5,1.5),ylim=c(-0.5,1.5),zlim=c(-0.5,1.5))
segments3d(Vs[c(1,2,2,3,3,4,4,1,5,6,6,7,7,5),1],Vs[c(1,2,2,3,3,4,4,1,5,6,6,7,7,5),2],Vs[c(1,2,2,3,3,4,4,1,5,6,6,7,7,5),3],col=2)
Ntri<-20
for(i in 1:Ntri){
tmpalpha<-runif(1)
tmpbeta1<-runif(1)
tmpbeta2<-runif(1)
tmpbeta1.2<-min(tmpbeta1,tmpbeta2)
tmpbeta2.2<-max(tmpbeta1,tmpbeta2)
tmpL<-runif(1)*L
tmpv5<-c(tmpalpha,tmpbeta1.2,0)
tmpv6<-c(tmpalpha,tmpbeta2.2,0)
tmpv7<-c(tmpalpha,tmpbeta2.2,tmpL)
tri<-rbind(tmpv5,tmpv6,tmpv7)
triangles3d(tri)
}