Make a 3D rendered plot of time-series

Question

I have a set of 3D coordinates (below - just for a single point, in 3D space):

x <- c(-521.531433, -521.511658, -521.515259, -521.518127, -521.563416, -521.558044, -521.571228, -521.607178, -521.631165, -521.659973)
y <- c(154.499557, 154.479568, 154.438705, 154.398682, 154.580688, 154.365189, 154.3564, 154.559189, 154.341309, 154.344223)
z <- c(864.379272, 864.354675, 864.365479, 864.363831, 864.495667, 864.35498, 864.358582, 864.50415, 864.35553, 864.359863)
xyz <- data.frame(x,y,z)

I need to make a time-series plot of this point with a 3D rendering (so I can rotate the plot, etc.). The plot will visualize a trajectory of the point above in time (for example in the form of solid line). I used 'rgl' package with plot3d method, but I can't make it to plot time-series (below, just plot a single point from first frame in time-series):

require(rgl)    
plot3d(xyz[1,1],xyz[1,2],xyz[1,3],axes=F,xlab="",ylab="",zlab="") 

I found this post, but it doesn't really deal with a real-time rendered 3D plots. I would appreciate any suggestions. Thank you.

Answer 1

The solution was simpler than I thought and the problem was that I didn't use as.matrix on my data. I was getting error (list) object cannot be coerced to type 'double' when I was simply trying to plot my entire dataset using plot3d (found a solution for this here). So, if you need to plot time-series of set of coordinates (in my case motion capture data of two actors) here is my complete solution (only works with the data set below!):

• download example data set

• read the above data into a table:

  data <- read.table("Bob12.txt",sep="\t")
  

• extract XYZ coordinates into a separate matrixes:

  x <- as.matrix(subset(data,select=seq(1,88,3)))
  y <- as.matrix(subset(data,select=seq(2,89,3)))
  z <- as.matrix(subset(data,select=seq(3,90,3)))
  

• plot the coordinates on a nice, 3D rendered plot using 'rgl' package:

  require(rgl)
  plot3d(x[1:nrow(x),],y[1:nrow(y),],z[1:nrow(z),],axes=F,xlab="",ylab="",zlab="")
  

You should get something like on the image below (but you can rotate it etc.) - hope you can recognise there are joint centers for people there. I still need to tweak it to make it visually better - to have first frame as a points (to clearly see actor's joints), then a visible break, and then the rest of frames as a lines.

Answer 2

If you read help(plot3d) you can see how to draw lines:

require(rgl)    
plot3d(xyz$x,xyz$y,xyz$z,type="l")

Is that what you want?

Answer 3

How about this? It uses rgl.pop() to remove a point and a line and draw them as a trail - change the sleep argument to control the speed:

ts <- function(xyz,sleep=0.3){
  plot3d(xyz,type="n")
  n = nrow(xyz)
  p = points3d(xyz[1,])
  l = lines3d(xyz[1,])
  for(i in 2:n){
    Sys.sleep(sleep)
    rgl.pop("shapes",p)
    rgl.pop("shapes",l)
    p=points3d(xyz[i,])
    l=lines3d(xyz[1:i,])
  }
}