CODEWITHSUNDEEP
rplotrgl
naco
naco

Reputation: 373

How do I make planes in RGL thicker?

I will try 3D printing data to make some nice visual illustration for a binary classification example.

Here is my 3D plot:

require(rgl)
#Get example data from mtcars and normalize to range 0:1
fun_norm <- function(k){(k-min(k))/(max(k)-min(k))}
x_norm <- fun_norm(mtcars$drat)
y_norm <- fun_norm(mtcars$mpg)
z_norm <- fun_norm(mtcars$qsec)

#Plot nice big spheres with rgl that I hope will look good after 3D printing
plot3d(x_norm, y_norm, z_norm, type="s", radius = 0.02, aspect = T)
#The sticks are meant to suspend the spheres in the air
plot3d(x_norm, y_norm, z_norm, type="h", lwd = 5, aspect = T, add = T)
#Nice thick gridline that will also be printed
grid3d(c("x","y","z"), lwd = 5)

Next, I wanted to add a z=0 plane, inspired by this blog here describing the r2stl written by Ian Walker. It is supposed to be the foundation of the printed structure that holds everything together.

planes3d(a=0, b=0, c=1, d=0)

However, it has no volume, it is a thin slab with height=0. I want it to form a solid base for the printed structure, which is meant to keep everything together (check out the aforementioned blog for more details, his examples are great). How do I increase the thickness of my z=0 plane to achieve the same effect?

Here is the final step to exporting as STL:

writeSTL("test.stl")

One can view the final product really nicely using the open source Meshlab as recommended by Ian in the blog.

Additional remark: I noticed that the thin plane is also separate from the grids that I added on the -z face of the cube and is floating. This might also cause a problem when printing. How can I merge the grids with the z=0 plane? (I will be sending the STL file to a friend who will print for me, I want to make things as easy for him as possible)

Upvotes: 2

Views: 208

Answers (2)

user101089
user101089

Reputation: 3992

In the matlib package, there's a function regvec3d() that draws a vector space representation of a 2-predictor multiple regression model. The plot method for the result of the function has an argument show.base that draws the base x1-x2 plane, and draws it thicker if show.base >0.

It is a simple hack that just draws a second version of the plane at a small offset. Maybe this will be enough for your application.

if (show.base > 0) planes3d(0, 0, 1, 0, color=col.plane, alpha=0.2)
if (show.base > 1) planes3d(0, 0, 1, -.01, color=col.plane, alpha=0.1)

Upvotes: 1

user2554330
user2554330

Reputation: 44887

You can't make a plane thicker. You can make a solid shape (extrude3d() is the function to use). It won't adapt itself to the bounding box the way a plane does, so you would need to draw it last.

For example, 

example(plot3d)
bbox <- par3d("bbox")
slab <- translate3d(extrude3d(bbox[c(1,2,2,1)], bbox[c(3,3,4,4)], 0.5),
                    0,0, bbox[5])
shade3d(slab, col = "gray")

produces this output:

sample output

This still isn't printable (the points have no support), but it should get you started.

Upvotes: 1

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