R help - Apr 2016 - Question about function DrawDensity3D {VecStatGraphs3D}

Hi,

Here is the function DrawDensity3D in package VecStatGraphs3D. My 
question is: if we use more layers than one, could we change the 
function in a way that in the final plot only the outmost layer is drawn 
(the inner layers omitted)?

Best regards,

Atte Tenkanen

function (vectors, Div = 40, Layers = 3, DrawAxes = FALSE)
{
     open3d(windowRect = c(100, 100, 800, 800))
     bg3d("white")
     Cx = vectors[, 1]
     Cy = vectors[, 2]
     Cz = vectors[, 3]
     Cr <- kde3d(x = Cx, y = Cy, z = Cz, n = Div)
     th <- seq(min(Cr$d), max(Cr$d), len = Layers + 2)
     ramp <- colorRamp(c("white", "yellow",
"red"))
     colo <- rgb(ramp(seq(0, 1, length = Layers)), maxColorValue = 255)
     al <- seq(0.1, 0.6, len = Layers)
     module = sqrt(Cx * Cx + Cy * Cy + Cz * Cz)
     spheres3d(0, 0, 0, radius = max(module), color = "black",
         front = "line", back = "line", lwd = 1, smooth =
TRUE,
         lit = TRUE, line_antialias = FALSE, alpha = 0.2)
     x <- c(0, max(module), 0, 0)
     y <- c(0, 0, max(module), 0)
     z <- c(0, 0, 0, max(module))
     labels <- c("", "X", "Y", "Z")
     i <- c(1, 2, 1, 3, 1, 4)
     text3d(x, y, z, labels, adj = 0.8, cex = 1.5, font = 2, color = 
"black")
     segments3d(x[i], y[i], z[i], lwd = 3)
     rgl.points(x = Cx, y = Cy, z = Cz, size = 3, color = "black")
     contour3d(Cr$d, level = th[c(-1, -(Layers + 2))], x = Cr$x,
         y = Cr$y, z = Cr$z, alpha = al, color = colo, add = TRUE,
         engine = "rgl", fill = TRUE, smooth = 2, material =
"shiny")
     if (DrawAxes == TRUE) {
         axes3d()
     }
}