Tcomp1<-T[,1] ........................T values for the first PC
Tcomp2<-T[,2] ........................T values for the second PC
Tcomp3<-T[,3] ........................T values for the third PC
Now there are diferent options to see this T matrix in 3D:
One of them can be:
library(scatterplot3d)scatterplot3d(Tcomp1,Tcomp2,Tcomp3)
and we get a plot.
library(rgl)
plot3d(Tcomp1,Tcomp2,Tcomp3,col="red",size=5)
We can move the plot with the mouse and see the different faces of the cube.